tag:theconversation.com,2011:/global/topics/tongue-11747/articlesTongue – The Conversation2021-07-13T20:11:31Ztag:theconversation.com,2011:article/1545522021-07-13T20:11:31Z2021-07-13T20:11:31ZHow do you teach a child to swallow a pill? Hint: use lollies<figure><img src="https://images.theconversation.com/files/410240/original/file-20210707-21-12b5x7.jpg?ixlib=rb-1.1.0&rect=0%2C1%2C1000%2C663&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pill-child-mouth-1035027634">from www.shutterstock.com</a></span></figcaption></figure><p>When was the last time you swallowed a pill, be it a tablet or capsule? This morning or sometime in the past week? Now, can you remember the very first time you had to take a pill? Probably not. </p>
<p>Unlike your first kiss, there is usually nothing remarkable about the first time you take a pill. But taking solid medicines orally <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6065591/">does not come naturally</a> and chances are you had to be taught how to do it. And because you don’t remember how you were taught it can be hard for parents to figure out how to teach their kids to do it too.</p>
<p>But here’s how to make the learning process fun and safe.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-we-burp-137493">Curious Kids: why do we burp?</a>
</strong>
</em>
</p>
<hr>
<h2>Is this necessary?</h2>
<p>Before trying to teach your child to swallow a pill, first see if your child really needs to learn.</p>
<p>Most medicines commonly used by children under 12 years of age are readily available as formulations other than pills. These include liquids, <a href="https://link.springer.com/chapter/10.1007/978-1-4419-1087-5_4">suspensions</a>, chewable tablets and <a href="https://www.healthline.com/health/general-use/how-to-use-rectal-suppositories">suppositories</a>. The liquids and suspensions usually come in palatable flavours. </p>
<p>Doctors can also write prescriptions to allow pharmacists <a href="https://www.nps.org.au/australian-prescriber/articles/extemporaneously-compounded-medicines-1">to compound (make up)</a> some drugs usually available as a pill into a suspension instead. </p>
<p>If these options aren’t available, you will need to teach your child to swallow a pill. You’ll also need to go down this path as your child gets older, their weight increases, and some of the child-friendly formulations are no longer suitable. That’s because the higher doses often needed can be impractical to give using children’s products. So it would be much easier and cheaper to use a tablet or a capsule.</p>
<p>However, don’t be tempted to <a href="https://theconversation.com/health-check-is-it-ok-to-chew-or-crush-your-medicine-39630">crush or break a pill for them, or ask them to chew it</a>, unless your pharmacist has given the go-ahead for that medicine. This can affect the way the medicine is absorbed, which could lead to an overdose.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-is-it-ok-to-chew-or-crush-your-medicine-39630">Health Check: is it OK to chew or crush your medicine?</a>
</strong>
</em>
</p>
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<h2>Turn it into a game</h2>
<p>Teaching relaxation techniques, learning by imitation or modelling, and learning by repetition and exercise are all useful ways to teach pill swallowing. However, <a href="https://www.hamiltonhealthsciences.ca/wp-content/uploads/2019/08/SwallowPillsHelpChild-lw.pdf">turning it into a game</a> is popular.</p>
<p>First of all, this method is NOT suitable for children under five. The mechanics of swallowing are too difficult for them to understand and both you and the child are likely to end up frustrated. Also, the younger they are, the smaller their throat and the likelihood something will get stuck.</p>
<p>The basis of the game is to start your child trying to swallow very small, everyday foodstuffs and work your way up to things the size of a pill. Lollies (candy) are best because you don’t have to convince your child to play the game.</p>
<p>More importantly, lollies are water soluble so if there are any problems you can ask your child to have a big drink of water to break it apart. If you don’t know if the lolly is water soluble, test it first in a glass of water to see if it dissolves.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sickly-sweet-or-just-right-how-genes-control-your-taste-for-sugar-113455">Sickly sweet or just right? How genes control your taste for sugar</a>
</strong>
</em>
</p>
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<h2>Ready, steady, go!</h2>
<p>Start your child on the smallest sized lolly. Ask them to sit up straight, facing forward, without tilting their head up or down. Ask them to take a sip of water before each lolly, to get them prepared for the swallowing action. Then ask them to place the lolly on their tongue (<a href="https://www.hamiltonhealthsciences.ca/wp-content/uploads/2019/08/SwallowPillsHelpChild-lw.pdf#:%7E:text=small%2C%20like%20a%20candy%20sprinkle,try%20a%20slightly%20larger%20candy.&text=Work%20up%20to%20a%20candy,your%20child%20will%20be%20taking.&text=candies.">towards the back is best</a>) and take another sip to wash it down.</p>
<p>If they can swallow that, move up to the next size. But if they can’t, ask them to chew and swallow it, and try again.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/410242/original/file-20210707-15-1x14tog.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Pile of snake lollies (candies)" src="https://images.theconversation.com/files/410242/original/file-20210707-15-1x14tog.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/410242/original/file-20210707-15-1x14tog.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/410242/original/file-20210707-15-1x14tog.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/410242/original/file-20210707-15-1x14tog.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/410242/original/file-20210707-15-1x14tog.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/410242/original/file-20210707-15-1x14tog.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/410242/original/file-20210707-15-1x14tog.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Snake lollies can come in handy and your child is unlikely to complain.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/snake-candies-close-1222479028">from www.shutterstock.com</a></span>
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</figure>
<p>Our version of the game uses lollies available in Australia, increasing in size: sprinkles (such as hundreds and thousands), Nerds, Tic Tacs, M&Ms (normal, not peanut or crispy), and then snakes.</p>
<p>With snakes, you can cut off and swallow the head, about the size of a pill, before cutting up pieces of the body to the same size.</p>
<h2>Some dos</h2>
<ul>
<li><p><strong>do joke around and make the activity fun</strong>. Get family involved as children need to be comfortable when playing</p></li>
<li><p><strong>do make sure it’s the only activity they are doing</strong>. You want your child’s full attention</p></li>
<li><p><strong>do give praise</strong>. The game is all about building confidence</p></li>
<li><p><strong>do put the lolly into a soft food stuff if you want</strong>. Some children find lollies, or even real pills, easier to swallow if they are in a small spoonful of pureed fruit or custard. Don’t use peanut butter as that is sticky and hard to swallow</p></li>
<li><p><strong>do consolidate their skill when they are finally successful</strong>. Once they can swallow a tablet or capsule sized lollie, keep your child’s confidence up by asking them to swallow an age-appropriate vitamin pill every now and then.</p></li>
</ul>
<h2>Some don'ts</h2>
<ul>
<li><p><strong>don’t stop on a stuck point</strong>. If your child has difficulty with a particular sized lolly that day drop back down to the size they can do so you finish on a win</p></li>
<li><p><strong>don’t use a sultana or peanut-based lolly</strong>. These do not dissolve in water and if they get stuck, become be a choking hazard</p></li>
<li><p><strong>don’t ask children to lay on their back</strong>. <a href="https://www.everydayhealth.com/specialists/healthy-living/when-a-pill-gets-stuck/#:%7E:text=Never%20take%20a%20medication%20when,pill%20is%20%E2%80%9Cchased%E2%80%9D%20down.">This can make it more difficult to swallow</a>. Instead just have them sit up straight. If they like, they can tilt their head forward to place the lolly in their mouth, and then when they are ready to swallow, they can tilt their head slightly back to help it go down.</p></li>
</ul>
<h2>Final take-home advice</h2>
<p>Teaching your child to swallow a pill is not easy and is likely to take weeks. Most kids will get stuck at one size of lolly at some stage. And they’ll likely not be able to swallow the largest lolly the first time they try.</p>
<p>This is normal, so persevere and keep the game fun. Your child will get there.</p><img src="https://counter.theconversation.com/content/154552/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Associate Professor Wheate in the past has received funding from the ACT Cancer Council, Tenovus Scotland, Medical Research Scotland, Scottish Crucible, and the Scottish Universities Life Sciences Alliance. He is Fellow of the Royal Australian Chemical Institute and a member of the Australasian Pharmaceutical Science Association. Nial is science director of the medicinal cannabis company Canngea Pty Ltd, a board member of the Australian Medicinal Cannabis Association, and a Standards Australia committee member for sunscreen agents.</span></em></p><p class="fine-print"><em><span>Elise Schubert is a registered pharmacist and also receives a scholarship from the University of Sydney and Canngea Pty Ltd. </span></em></p>Here’s how to make the learning process fun and safe.Nial Wheate, Associate Professor of the Sydney Pharmacy School, University of SydneyElise Schubert, Pharmacist and PhD Candidate, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1395612020-06-11T01:39:14Z2020-06-11T01:39:14ZMy baby has ‘tongue-tie’. Should I be worried?<figure><img src="https://images.theconversation.com/files/340832/original/file-20200610-34661-1t42r0s.jpg?ixlib=rb-1.1.0&rect=0%2C1%2C1000%2C664&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/crying-baby-on-his-first-day-18806152">Shutterstock</a></span></figcaption></figure><p>Congratulations on your new bundle of joy! Is it joyful? What if your baby cries, fusses and isn’t feeding well? Perhaps you’ve tried breast and bottle-feeding without success. </p>
<p>After talking to family, friends and searching social media, someone mentions your baby may have a tongue-tie. Could this be the answer?</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/essays-on-health-australia-is-failing-new-parents-with-conflicting-advice-its-urgent-we-get-it-right-77943">Essays on health: Australia is failing new parents with conflicting advice – it's urgent we get it right</a>
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<h2>What is tongue-tie?</h2>
<p><a href="http://www.ada.org.au/ankyloglossia">Tongue-tie</a> (or ankyloglossia) is when the tissue under the tongue is short, thick or tight. This can restrict how the tongue moves. </p>
<p>Babies, children and adults can have tongue-tie, with <a href="https://pubmed.ncbi.nlm.nih.gov/17872781/">4-10%</a> of the population affected. This means
<a href="https://www.abs.gov.au/ausstats/abs@.nsf/0/F41B99AB234B2074CA25792F00161838?Opendocument">12,000-32,000</a> Australian children are born with a tongue-tie each year.</p>
<p>We don’t know the precise cause of tongue-tie. But it can run in some <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3408277/">families</a> and occurs more in males than females. </p>
<h2>How is it diagnosed?</h2>
<p>The diagnosis includes a health professional looking at the tongue’s structure and appearance, and thoroughly testing how the tongue moves and works (known as a “functional assessment”).</p>
<p>Your child health nurse or lactation consultant may suspect your baby has tongue-tie. For older children or adults, a speech pathologist may notice tongue restriction affecting eating, drinking and speech.</p>
<h2>Will it affect my baby’s feeding or speech?</h2>
<p><strong>Impact on breastfeeding</strong></p>
<p>Tongue-tie can <a href="https://www.breastfeeding.asn.au/bf-info/tongue-tie">make it hard</a> for babies to breastfeed. In some babies, it can <a href="https://journals.sagepub.com/doi/abs/10.1177/0890334404266976?casa_token=03PuNlSRPrQAAAAA:q_p0WOPDEH5ob5DczAlXtiJ5C9W9fJrNL7ncgvwQ_LHir45UY7aCVhk58VfWTYrj9zoT_GSMyG13">cause problems</a> latching to the breast, pain for the mother, and more frequent feeds due to inadequate intake. </p>
<p>The Australian Breastfeeding Association outlines the <a href="https://www.breastfeeding.asn.au/bf-info/tongue-tie">following signs</a> that may relate to tongue-tie:</p>
<ul>
<li>baby is not gaining enough weight</li>
<li>breastfeeding is painful</li>
<li>the nipple is damaged or flattened after breastfeeding.</li>
</ul>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"861688702782783489"}"></div></p>
<p>Tongue-tie in <a href="https://journals.sagepub.com/doi/full/10.1177/0009922820928055?casa_token=mMzpogLldkcAAAAA%3Abw9Zv8uwyQ5ZiJx9PnQ_-btMzQSoGNd3xRPoxls5zZ9Oe5E0J_VzRMSaFtBPpIU-k99zXbIK5YPJ">older children</a> and <a href="https://www.researchgate.net/profile/Harsha_Babu3/publication/47929335_Surgical_Management_of_Ankyloglossia_-_A_Case_Report/links/09e415120eafb578e5000000/Surgical-Management-of-Ankyloglossia-A-Case-Report.pdf">adults</a> can also restrict tongue movements, causing difficulties eating. </p>
<p><strong>Impact on speech</strong></p>
<p>Occasionally tongue-tie causes significant restriction where a child cannot produce <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/ped.12474?casa_token=W8s2ZDqtWQ8AAAAA%3AgtRi0XJ5CWHJ7uwKXVJC7qBvz2QLCqqQ9eWNW-RUmD_asFCAJ3GiUGvNSTMr6kqd-hrJ9LqR5dTx4a">sounds</a> correctly. This is particularly the case with sounds that require the tongue to elevate, such as “t”, “s” and “r”.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/common-myths-about-speech-problems-in-children-38599">Common myths about speech problems in children</a>
</strong>
</em>
</p>
<hr>
<h2>How is it treated?</h2>
<p>If a tongue-tie is not causing problems with breastfeeding, eating, drinking or speech production, then treatment is <a href="http://www.ada.org.au/ankyloglossia">not recommended</a>. But when treatment is warranted, there are non-surgical and surgical approaches.</p>
<p><strong>Non-surgical approaches</strong></p>
<p>Non-surgical management might include seeing a lactation consultant who can provide breastfeeding advice, preferably one certified as an <a href="https://iblce.org/">International Board Certified Lactation Consultant</a>.</p>
<p>A speech pathologist can assess and treat your baby or child’s feeding, eating, drinking and speech. If non-surgical methods don’t work or are not suitable, surgery may be warranted.</p>
<p><strong>Surgery</strong></p>
<p><a href="https://www.ncbi.nlm.nih.gov/books/NBK299112/">Surgical options</a> include snipping the tissue under the tongue with scissors or a scalpel, laser frenotomy (dividing the tissue under the tongue, called the frenum), frenuloplasty (dividing the frenum and using stitches), and frenectomy (removal of the frenum). A paediatrician, ear, nose and throat surgeon, dentist or surgeon can perform the surgery on infants, children or adults. </p>
<p>Some experts are concerned about the large increase in the number of children surgically treated for tongue-tie <a href="https://pubmed.ncbi.nlm.nih.gov/28168891/">globally</a>. In Australia, surgery rates for frenotomy increased by <a href="https://pubmed.ncbi.nlm.nih.gov/29385976/">420%</a> from 2006 to 2016.</p>
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<p>This prompted a group of health professionals from a number of disciplines to <a href="https://www.ada.org.au/ankyloglossia">recently warn against</a> unnecessary surgery for tongue-tie, before a comprehensive assessment of tongue structure and function. </p>
<h2>Does surgery work? Are there risks?</h2>
<p>A <a href="https://tonguetieal.com/wp-content/uploads/2020/05/Baxter-et-al-2020-Feeding-Speech-Sleep-Improvements.pdf">small study</a> shows parents of preschool children reported improvements in their child’s speech after surgery.</p>
<p>A <a href="https://www.sciencedirect.com/science/article/abs/pii/S0165587620301786">larger study</a> of children aged two to four found no difference between the speech or tongue movement of tongue-tied children who had surgery as an infant and those who didn’t.</p>
<p>Therefore, surgery is <a href="https://www.ada.org.au/ankyloglossia">not</a> <a href="https://www.sciencedirect.com/science/article/abs/pii/S0165587620301786">recommended</a> for babies with tongue-tie during infancy, with the sole aim of improving speech later in life.</p>
<p>A large study of 215 babies under three months old reported <a href="https://journals.sagepub.com/doi/abs/10.1177/0890334404266976?casa_token=t_C4NmXiFD8AAAAA:WvkOUaFSvkUUPcxL9j2-wXXFgQq74GxnjC1PjIX_sH_iHTEtyaI-3k55De4j6TFYOCjY8kBFnhtG">improvements in breastfeeding</a> following surgery. In a more recent <a href="https://pediatrics.aappublications.org/content/135/6/e1458.short?casa_token=dmMScsYfORwAAAAA:c2GmYCgSgKjh7HgWz39Gyl99BGoTG2RkiXnf7LL3bJZtAihmJ-sdtG8f3KlMMvnS_3FeCPqfZS-W">review</a>, mothers reported improvements in breastfeeding and nipple pain. </p>
<p>The <a href="https://www.breastfeeding.asn.au/bf-info/tongue-tie#:%7E:text=If%20it%20is%20decided%20that,professionals%20performing%20tongue%2Dtie%20releases">Australian Breastfeeding Association</a> recommends surgery to release a tight frenum for babies with a tongue-tie having difficulties breastfeeding.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/deep-cuts-under-babies-tongues-are-unlikely-to-solve-breastfeeding-problems-54040">Deep cuts under babies' tongues are unlikely to solve breastfeeding problems</a>
</strong>
</em>
</p>
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<p>As with any surgical procedure, there are potential risks. <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/jpc.14682">Babies</a> <a href="https://www.sciencedaily.com/releases/2019/11/191120121133.htm">can experience</a> pain, bleeding, breathing problems, weight loss and poor feeding after minor surgery for tongue-tie. </p>
<p>Your dentist or surgeon will be able to discuss these potential complications, as they apply to your particular situation.</p>
<h2>Where to go for help?</h2>
<p>It can be challenging for parents to know which health professional to see with any concerns about your child’s breastfeeding, eating, drinking or speech. Different professions differ in how they assess and manage tongue-tie.</p>
<p>A lactation consultant, child health nurse, or speech pathologist are good places to start to assess how the tongue looks and works during feeding and talking.</p>
<p>The Australian Dental Association <a href="http://www.ada.org.au/ankyloglossia">recommends</a> a multidisciplinary approach, including lactation consultants, speech pathologists, paediatricians, and dentists or surgeons.</p>
<p>Whichever health professional you see, they will still need to properly assess how the tongue works to guide any future treatment.</p>
<hr>
<p><em>For more information about tongue-tie, see websites from the <a href="https://www.breastfeeding.asn.au/bf-info/tongue-tie">Australian Breastfeeding Association</a>, <a href="https://www.ada.org.au/News-Media/News-and-Release/Latest-News/Ankyloglossia-statement-4-June-2020">Australian Dental Association</a> and <a href="https://www.speechpathologyaustralia.org.au/SPAweb/Resources_for_the_Public/Fact_Sheets/SPAweb/Resources_for_the_Public/Fact_Sheets/Fact_Sheets.aspx?hkey=e0ad33fb-f640-45b1-8a06-11ed2b73f293">Speech Pathology Australia</a>.</em></p><img src="https://counter.theconversation.com/content/139561/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Some experts are concerned about the rise in surgery to treat the common condition known as tongue-tie, when the tissue under the tongue is short, thick or tight. Here’s a guide to your options.Sharon Smart, Lecturer, School of Occupational Therapy, Social Work and Speech Pathology and Speech Pathologist., Curtin UniversityMary Claessen, Senior Lecturer, School of Occupational Therapy, Social Work and Speech Pathology, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1037442019-01-16T00:06:52Z2019-01-16T00:06:52ZCurious Kids: how do tongues taste food?<figure><img src="https://images.theconversation.com/files/252774/original/file-20190107-32145-12tv3t8.jpg?ixlib=rb-1.1.0&rect=5%2C0%2C992%2C666&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Your tongue has special parts, bundled together as taste buds, that pick up flavour. But your other senses also help your brain work out how something tastes.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/theloushe/4969741592/in/photolist-578e4-btvDyb-nN5GgH-yA1n7-4TXJg2-8dUuKJ-T9fx9A-8dUsgC-6X5sWY-578e3-2UNLSe-hnNcu-5bomEF-WcHAM5-docpAz-DoCa33-G8umGo-rVJovA-5bLSDc-7MboFw-4KUj1Y-docxRy-rXNMXG-Q1uGpF-6XszFr-Dzf5tm-Lt2d55-24M5dVJ-AK95dx-v3xzyv-riz5rw-2Spdb1-rXWmR6-9P71mP-eSrqB8-dgxp2W-ckcpYU-ckcpHC-c4KNJ7-8KuSKj-8FGXYB-8ziXDR-8zae2S-8z76mH-8w8ziy-8mP2GQ-7KfoTf-4D8Pdj-3cEycT-iaffP">Flickr/Jessica Lucia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. Kids can send questions to curiouskids@theconversation.edu.au. You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>How do tongues taste food? – Ridley, age 4, Melbourne.</strong></p>
</blockquote>
<hr>
<p>Dear Ridley,</p>
<p>This is a really good question. Tasting food actually uses all of your senses. Your senses gather up all the information and combine it into a message about the taste of food that gets sent to your brain. For example, your eyes help you recognise food and remember how it tastes.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/251163/original/file-20181218-27767-1rmdcm3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/251163/original/file-20181218-27767-1rmdcm3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/251163/original/file-20181218-27767-1rmdcm3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/251163/original/file-20181218-27767-1rmdcm3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/251163/original/file-20181218-27767-1rmdcm3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/251163/original/file-20181218-27767-1rmdcm3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/251163/original/file-20181218-27767-1rmdcm3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/251163/original/file-20181218-27767-1rmdcm3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It’s not just about the tongue. The five senses - taste, touch, sight, hearing and smell – help collect messages about a food and send it to your brain.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-do-we-get-allergic-to-food-82503">Curious Kids: How do we get allergic to food?</a>
</strong>
</em>
</p>
<hr>
<p>Your tongue has special parts that pick up flavour, bundled together as taste buds. They help you taste different flavours, like sweet, salty, sour, bitter, and a special one called “umami” which some people <a href="https://www.sbs.com.au/food/article/2017/01/20/whats-umami-all-about">say</a> is a bit like a mix of all the others put together. </p>
<p>The taste buds pick up clues about how a food tastes and sends messages about it to your brain along special wires called nerves. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/252773/original/file-20190107-32124-1sfs0cu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/252773/original/file-20190107-32124-1sfs0cu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252773/original/file-20190107-32124-1sfs0cu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252773/original/file-20190107-32124-1sfs0cu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252773/original/file-20190107-32124-1sfs0cu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252773/original/file-20190107-32124-1sfs0cu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=487&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252773/original/file-20190107-32124-1sfs0cu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=487&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252773/original/file-20190107-32124-1sfs0cu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=487&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Your brain gets messages from your taste buds via nerves.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>To taste something properly, you need to chew food into small pieces and to have a lot of drool, or saliva. This help the flavour molecules (also known as “tastants”) reach your taste buds. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/252771/original/file-20190107-32127-qo2at3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/252771/original/file-20190107-32127-qo2at3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252771/original/file-20190107-32127-qo2at3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252771/original/file-20190107-32127-qo2at3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252771/original/file-20190107-32127-qo2at3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252771/original/file-20190107-32127-qo2at3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252771/original/file-20190107-32127-qo2at3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252771/original/file-20190107-32127-qo2at3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This picture shows a close-up of taste buds on a tongue.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Try this experiment: if you lick a piece of sliced apple, how does it taste? Now drink some water to wash away the flavour, and take a bite of the apple and chew it up. When you cut an apple, only some flavour is released. But if you chew it into smaller pieces, more flavour can escape into your mouth. </p>
<p>Foods taste sweeter if the sugar particles are smaller. Want to try another experiment? With permission, put some large sugar crystals on your tongue for five seconds. How sweet do they taste? Now rinse your mouth with water and put some fine icing sugar on your tongue – is it sweeter or less sweet than the big sugar crystals? </p>
<p>The smaller the sugar particles are, the easier it is for your tongue to taste the sweetness. (For the adults reading, this is because smaller particles have a higher surface area). This trick helps food scientists develop sweet foods with less sugar.</p>
<h2>Saliva and smell</h2>
<p>When you chew your food, you also produce saliva (or spit) which dissolves some of the food flavour for your to tongue taste. </p>
<p>Want to try another experiment? Stick out your tongue as far as it can go and dry the saliva off with some thick paper towel. While your tongue is still sticking out, have your parent put some food on your tongue, like yoghurt. How strong is the flavour? Next, pull your tongue back into your mouth and taste the food. Is the flavour stronger, weaker, or the same?</p>
<p>If your nose is blocked, food tastes weaker. This is because your nose also helps you “taste” food too. </p>
<p>Try it! While holding your nose closed, put some food in your mouth and chew. Can you taste it? While still eating the food, let go of your nose and keep eating. Is the flavour stronger, weaker, or the same? </p>
<p>In fact, without your sense of smell it can be hard to taste the difference between a raw apple and a raw onion!</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/252784/original/file-20190107-32142-109cuyl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/252784/original/file-20190107-32142-109cuyl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252784/original/file-20190107-32142-109cuyl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=496&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252784/original/file-20190107-32142-109cuyl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=496&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252784/original/file-20190107-32142-109cuyl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=496&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252784/original/file-20190107-32142-109cuyl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=624&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252784/original/file-20190107-32142-109cuyl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=624&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252784/original/file-20190107-32142-109cuyl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=624&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">When it comes to tasting flavour, your nose helps a lot.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/savannahgrandfather/312427606/in/photolist-tBgQS-e9JjjZ-26ZYtLy-c4NE35-4G3spu-5DEy7y-6BPnh-4YExex-85W1D8-4yEAbn-7ZEFsF-3By63S-28M2Rfn-T2WJQH-5iwZZB-WpoMc2-CwLZAd-QSawgU-hRao3x-ZdXVQh-61T135-PBtAzi-LTQJ2D-54vNyk-hyCDVb-4Ru36f-gns5G3-c5faC-2dwKEYh-22KbkQr-W4P2oJ-exd9r5-eRGnyM-5q3Sy1-8NB5w9-9zeSbD-kdq5hZ-2cdyEGM-f3p3kn-8kohiL-4XvnbF-37LB28-4UgRjJ-kZniSa-8kohtN-9N7NgD-N4qPC-nhKAiR-Zpckej-cXtwbC">Flickr/Bruce Tuten</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>So your tongue and nose work together to help you taste your food. I hope you can help your tongue taste more by chewing your food fully and using your saliva to help make the flavour stronger. </p>
<p>And if you have something to eat that you don’t like, try holding your nose!</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-some-people-find-some-foods-yummy-but-others-find-the-same-foods-yucky-77671">Curious Kids: why do some people find some foods yummy but others find the same foods yucky?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au</em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/103744/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Your tongue, saliva and nose work together to help you taste your food.Paulomi (Polly) Burey, Senior Lecturer (Food Science), University of Southern QueenslandUrsula Kennedy, Lecturer of Wine Science, University of Southern QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1070072018-11-18T21:54:51Z2018-11-18T21:54:51ZCool for cats: that spiny tongue does more than keep a cat well groomed<figure><img src="https://images.theconversation.com/files/245689/original/file-20181115-194494-a3sr15.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A domestic cat grooming its fur.</span> <span class="attribution"><span class="source">Image courtesy of Candler Hobbs (Georgia Institute of Technology, Atlanta).</span></span></figcaption></figure><p>Have you ever been licked by a cat? If so you’ll know the feline tongue feels more like sandpaper than satin. </p>
<p>A cat’s tongue is covered in hundreds of sharp, scoop-shaped spines made of keratin that spring into action during grooming. Until now we haven’t really known why their tongues are so rough. </p>
<p>But new research, <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1809544115">published today in Proceedings of the National Academy of Sciences</a>, shows they play a role in helping a cat keep cool.</p>
<h2>Cat grooming</h2>
<p>Domestic cats spend up to a quarter of their waking time grooming their fur coat to help remove pesky fleas and loose hairs. If they didn’t groom, then any excess debris could tangle fur, causing painful tugging of the skin, and even lead to infection.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/senate-inquiry-calls-for-tougher-rules-on-pet-food-in-australia-102410">Senate inquiry calls for tougher rules on pet food in Australia</a>
</strong>
</em>
</p>
<hr>
<p>But the new study reports something else that happens when a cat uses its tongue for grooming.</p>
<p>The scientists used CT scans of cat tongues to work out the structure of the spines, known as papillae. The spines are about 2mm long and have a U-shaped cavity at their tip (more on why later). The researchers also measured the hardness of the papillae, and found it is similar to that of human fingernails.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/245701/original/file-20181115-194509-o4a07.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/245701/original/file-20181115-194509-o4a07.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245701/original/file-20181115-194509-o4a07.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245701/original/file-20181115-194509-o4a07.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245701/original/file-20181115-194509-o4a07.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245701/original/file-20181115-194509-o4a07.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245701/original/file-20181115-194509-o4a07.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245701/original/file-20181115-194509-o4a07.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This is the surface of a cat’s tongue. Rigid, hollow papillae near the tongue tip are shown on the right, while soft, conical papillae near the throat are shown to the left.</span>
<span class="attribution"><span class="source">Alexis Noel</span></span>
</figcaption>
</figure>
<p>It got more interesting when the scientists used high-speed videography to work out what happens to the spines when a cat is grooming. Only the spines at the end of the tongue contact the fur during grooming. These are larger and not as closely packed as the spines nearer the bottom of the tongue.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/245707/original/file-20181115-194513-oocc4g.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/245707/original/file-20181115-194513-oocc4g.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/245707/original/file-20181115-194513-oocc4g.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/245707/original/file-20181115-194513-oocc4g.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/245707/original/file-20181115-194513-oocc4g.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/245707/original/file-20181115-194513-oocc4g.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/245707/original/file-20181115-194513-oocc4g.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/245707/original/file-20181115-194513-oocc4g.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A slice of a cat tongue, displaying papillae embedded in tissue.</span>
<span class="attribution"><span class="source">Image courtesy of Taren Carter (photographer).</span></span>
</figcaption>
</figure>
<p>As a cat grooms, there are four steps. First the tongue is extended out of the mouth. Then the muscles in the tongue expand the surface, and the spines rotate to become perpendicular to the tongue. </p>
<p>In the final two steps the tongue sweeps through the fur and is taken back into the mouth with a U-shaped curl. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/grbxv5JpnCs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This is a black cat grooming its fur, displaying the papillae on the tongue.</span></figcaption>
</figure>
<p>Using some fake fur and a force plate, the scientists calculated that with the amount of compression of the tongue on the fur, the spines can actually contact the skin of the cat. </p>
<p>This is where it gets even more interesting – and also a bit icky, as we need to think about cat saliva.</p>
<h2>The saliva action</h2>
<p>The U-shaped cavity in the tip of the spines, which we mentioned earlier, acts as a wick in the mouth to take up saliva. This is the same action as when you put the tip of a tissue in water and the water creeps up the tissue.</p>
<p>Because scientists like to work out the detail, they calculated that these cavities would take up around 4μL (microlitres) of saliva across 290 spines. (It would take around 1,200 times this amount of saliva to fill a 5ml metric teaspoon.) </p>
<p>This 4μl is only around 5% of the total saliva on the surface of the cat’s tongue. Not much, but it has a really important function as it can deposit saliva right down to a cat’s skin.</p>
<p>The scientists used the estimate that cats spend around a quarter of their time awake grooming (about 2.4 hours a day) and lick about once per second.</p>
<p>This means cats can lose around a quarter of the total heat they need to lose per day through the tiny bit of saliva in their tongue spines. (We lose heat through liquid by sweating when we’re hot.)</p>
<h2>Cool for cats</h2>
<p>Many (not all) cats live in hot climates, so this would be really important for their survival. The researchers looked at the tongues of several species of cat, including domestic cat, bobcat, cougar, snow leopard, tiger and lion.</p>
<p>Most cats groom themselves very effectively, helped by enzymes (special chemicals) in their saliva that dissolve blood and other debris.</p>
<p>By working out how far the spines penetrate cat fur, and measuring the length of fur in different breeds, the scientists also worked out the only cats that can’t groom themselves effectively are domestic Persians, which are typically long-haired.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/chocolate-labradors-die-earlier-than-yellow-or-black-and-have-more-disease-105366">Chocolate Labradors die earlier than yellow or black, and have more disease</a>
</strong>
</em>
</p>
<hr>
<p>This means if you own a Persian you need to take the time to brush them, or else matts form and can damage their skin and lead to infections. But here’s where the scientists made another breakthrough.</p>
<h2>A new brush</h2>
<p>In the final part of this research, the scientists used the knowledge they gained about the spiny form of a cat’s tongue, and used 3D printing to develop a better grooming brush to use on cats.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ejv7YYAc414?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The prototype grooming tool allows easy removal of hair after grooming.</span></figcaption>
</figure>
<p>The scientists say the biology-inspired brush should help remove allergens from cat fur, and help with the application of any cleaning lotions and medications on cats’ skin.</p>
<p>The brush design may also help inspire news ways to clean other complex hairy surfaces. </p>
<p>So next time you watch a cat grooming, take a moment to marvel at just how much awesome science is involved in the evolutionary design of its tongue.</p><img src="https://counter.theconversation.com/content/107007/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Susan Hazel is on the Dog & Cat Management Board of South Australia. </span></em></p>Domestic cats spend a quarter of their waking hours grooming. But that tongue action on the fur does more than keep fur clean – it also helps keep a cat cool.Susan Hazel, Senior Lecturer, School of Animal and Veterinary Science, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/720642017-02-01T00:02:26Z2017-02-01T00:02:26ZThe frog tongue is a high-speed adhesive<figure><img src="https://images.theconversation.com/files/154678/original/image-20170130-7894-20l6t5.jpg?ixlib=rb-1.1.0&rect=5%2C410%2C3384%2C2273&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Gotcha, five times faster than the blink of an eye. </span> <span class="attribution"><span class="source">Candler Hobbs/Georgia Tech</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>How does one get stuck studying frog tongues? Our study into the sticky, slimy world of frogs all began with a <a href="https://www.youtube.com/watch?v=LbNl3J8HXw4">humorous video</a> of a real African bullfrog lunging at fake insects in a mobile game. This frog was clearly an expert at gaming; the speed and accuracy of its tongue could rival the thumbs of texting teenagers.</p>
<figure>
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<figcaption><span class="caption">The frog that was the genesis of the authors’ tongue research.</span></figcaption>
</figure>
<p>Further YouTube research yielded amazing videos of frogs eating <a href="https://www.youtube.com/watch?v=6AILF4Spwpo">mice</a>, <a href="https://www.youtube.com/watch?v=b-K0KcbUWmI">tarantulas</a> and even other <a href="https://www.youtube.com/watch?v=2kwrWl8zWdg">frogs</a>. </p>
<p>The versatile frog tongue can grab wet, hairy and slippery surfaces with equal ease. It does a lot better than our engineered adhesives – not even household tapes can firmly stick to wet or dusty surfaces. What makes this tongue even more impressive is its speed: Over 4,000 species of frog and toad <a href="http://psycnet.apa.org/psycinfo/1990-97523-000">snag prey faster than a human can blink</a>. What makes the frog tongue so uniquely sticky? <a href="http://dx.doi.org/10.1098/rsif.2016.0764">Our group aimed to find out</a>.</p>
<h2>Baseline frog tongue knowledge</h2>
<p>Early modern scientific attention to frog tongues came in 1849, when biologist Augustus Waller published the <a href="http://dx.doi.org/10.1098/rstl.1849.0010">first documented frog tongue study</a> on nerves and papillae – the surface microstructures found on the tongue. Waller was fascinated with the soft, sticky nature of the frog tongue and what he called:</p>
<blockquote>
<p>“the peculiar advantages possessed by the tongue of the living frog…the extreme elasticity and transparency of this organ induced me to submit it to the microscope.”</p>
</blockquote>
<p>Fast-forward 165 years, when biomechanics researchers Kleinteich and Gorb were the first to <a href="http://dx.doi.org/10.1038/srep05225">measure tongue forces in the horned frog</a> <em>Ceratophrys cranwelli</em>. They found in 2014 that frog adhesion forces can reach up to 1.4 times the body weight. That means the sticky frog tongue is strong enough to lift nearly twice its own weight. They postulated that the <a href="http://dx.doi.org/10.1098/rsos.150333">tongue acts like sticky tape or a pressure-sensitive adhesive</a> – a permanently tacky surface that adheres to substrates under light pressure.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155018/original/image-20170131-3244-7r5phb.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Frog tongue holding up a petri dish just with its stickiness.</span>
<span class="attribution"><span class="source">Alexis Noel/Georgia Tech</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>To begin our own study on sticky frog tongues, we filmed various frogs and toads eating insects using high-speed videography. We found that the frog’s tongue is able to capture an insect in under 0.07 seconds, five times faster than a human eye blink. In addition, insect acceleration toward the frog’s mouth during capture can reach 12 times the acceleration of gravity. For comparison, astronauts normally experience around three times the acceleration of gravity during a rocket launch.</p>
<h2>On to the materials testing</h2>
<p>Thoroughly intrigued, we wanted to understand how the sticky tongue holds onto prey so well at high accelerations. We first had to gather some frog tongues. Here at Georgia Tech, we tracked down an on-campus biology dissection class, who used <a href="https://en.wikipedia.org/wiki/Northern_leopard_frog">northern leopard frogs</a> on a regular basis.</p>
<p>The plan was this: Poke the tongue tissue to determine softness, and spin the frog saliva between two plates to determine viscosity. Softness and viscosity are common metrics for comparing solid and fluid materials, respectively. Softness describes tongue deformation when a stretching force is applied, and viscosity describes saliva’s resistance to movement. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1067&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1067&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1067&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1340&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1340&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155021/original/image-20170131-3269-v89zmh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1340&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">When the indentation head pulls away from the tongue, it adheres and stretches.</span>
<span class="attribution"><span class="source">Alexis Noel/Georgia Tech</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Determining the softness of frog tongue tissue was no easy task. We had to create our own indentation tools since the tongue softness was beyond the capabilities of the traditional materials-testing equipment on campus. We decided to use an indentation machine, which pokes biological materials and measures forces. The force-displacement relationship can then describe softness based on the indentation head shape, such as a cylinder or sphere.</p>
<p>However, typical heads for indentation machines can cost US$500 or more. Not wanting to spend the money or wait on shipping, we decided to make our own spherical and flat-head indenters from stainless steel earrings. After our tests, we found frog tongues are about as soft as brain tissue and 10 times softer than the human tongue. Yes, we tested brain and human tongue tissue (post mortem) in the lab for comparison.</p>
<p>For testing saliva properties, we ran into a problem: The machine that would spin frog saliva required about one-fifth of a teaspoon of fluid to run the test. Sounds small, but not in the context of collecting frog spit. Amphibians are unique in that they <a href="http://dx.doi.org/10.1111/j.1463-6395.1969.tb00527.x">secrete saliva through glands located on their tongue</a>. So, one night we spent a few hours scraping 15 dead frog tongues to get a saliva sample large enough for the testing equipment.</p>
<p>How do you get saliva off a frog tongue? Easy. First, you pull the tongue out of the mouth. Second, you rub the tongue on a plastic sheet until a (tiny) saliva globule is formed. Globules form due to the long-chain mucus proteins that exist in the frog saliva, much like human saliva; these <a href="http://dx.doi.org/10.1007/BF00305337">proteins tangle like pasta when swirled</a>. Then you quickly grab the globule using tweezers and place it in an airtight container to reduce evaporation.</p>
<p>After testing, we were surprised to find that the saliva is a two-phase viscoelastic fluid. The two phases are dependent on how quickly the saliva is sheared, when resting between parallel plates. At low shear rates, the saliva is very thick and viscous; at high shear rates, the frog saliva becomes thin and liquidy. This is similar to paint, which is easily spread by a brush, yet remains firmly adhered on the wall. Its these two phases that give the saliva its reversibility in prey capture, for adhering and releasing an insect.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/26xFAMpG2R8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A South American horned frog demonstrates capturing a cricket in this slow motion video.</span></figcaption>
</figure>
<h2>To catch a cricket</h2>
<p>How does soft tissue and a two-phase saliva help the frog tongue stick to an insect? Let’s walk through a prey-capture scenario, which begins with a frog tongue zooming out of the mouth and slamming into an insect.</p>
<p>During this impact phase, the tongue deforms and wraps around the insect, increasing contact area. The saliva becomes liquidy, penetrating the insect cracks. As the frog pulls its tongue back into the mouth, the tissue stretches like a spring, reducing forces on the insect (similar to how a bungee cord reduces forces on your ankle). The saliva returns to its thick, viscous state, maintaining high grip on the insect. Once the insect is inside the mouth, the eyeballs push the insect down the throat, causing the saliva to once again become thin and liquidy. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/fwThZXXXdTc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Frogs’ eyeballs actually help them swallow their food by physically pushing what’s in the mouth back into the throat.</span></figcaption>
</figure>
<p>It’s possible that <a href="http://dx.doi.org/10.1098/rsif.2016.0764">untangling the adhesion secrets of frog tongues</a> could have future applications for things like high-speed adhesive mechanisms for conveyor belts, or fast grabbing mechanisms in soft robotics.</p>
<p>Most importantly, this work provides valuable insight into the biology and function of amphibians – 40 percent of which are in <a href="http://www.iucnredlist.org">catastrophic decline or already extinct</a>. Working with conservation organization <a href="http://www.amphibianfoundation.org">The Amphibian Foundation</a>, we had access to live and preserved species of frog. The results of our research provide us with a greater understanding of this imperiled group. The knowledge gathered on unique functions of frog and toad species can inform conservation decisions for managing populations in dynamic and declining ecosystems.</p>
<p>While it’s not easy being green, a frog may find comfort in the fact that its tongue is one amazing adhesive.</p>
<hr>
<p><em>Mark Mandica of <a href="http://www.amphibianfoundation.org">The Amphibian Foundation</a> collaborated on the <a href="http://dx.doi.org/10.1098/rsif.2016.0764">research published in Journal of the Royal Society Interface</a> and coauthored this article.</em></p><img src="https://counter.theconversation.com/content/72064/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This material is based upon work supported by the National Science Foundation Graduate Research Fellowship (DGE-1148903).</span></em></p><p class="fine-print"><em><span>David Hu does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>How do a frog’s tongue and saliva work together to be sticky enough to lift 1.4 times the animal’s body weight? Painstaking lab work found their spit switches between two distinct phases to nab prey.Alexis Noel, PhD Student in Biomechanics, Georgia Institute of TechnologyDavid Hu, Associate Professor of Mechanical Engineering and Biology, Adjunct Associate Professor of Physics, Georgia Institute of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/540402016-03-04T02:51:01Z2016-03-04T02:51:01ZDeep cuts under babies’ tongues are unlikely to solve breastfeeding problems<figure><img src="https://images.theconversation.com/files/113480/original/image-20160302-12134-zptncc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's unclear just how many infants are undergoing these procedures.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-212769577/stock-photo-mother-nursing-her-week-old-daughter-image-taken-at-davis-creek-regional-park-in-reno-nevada.html?src=1fUPBLjyCMg9VkVWQnlVIw-1-60">Tanya Little/Shutterstock</a></span></figcaption></figure><p>Breastfed infants diagnosed with “tongue tie” are being unnecessarily treated with deep laser or scissor cuts under both their tongue and upper lip in the first weeks and months of life. </p>
<p>In order to avoid re-healing of the surfaces, parents are <a href="http://www.kiddsteeth.com/dental-topics.php?mode=desktop#post-surgical-tongue-ties">often instructed</a> to pull the wounds apart multiple times a day for two or three weeks afterwards, causing further pain and discomfort. </p>
<p>It’s unclear just how many infants are undergoing these procedures in Australia, the United Kingdom and North America. But there is little evidence to support the practice. </p>
<p>Classic tongue tie can usually be treated relatively painlessly with a simple snip, without the need for deep surgical cuts. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/OEWyaVUL-co?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Classic tongue tie is treated with a non-invasive snip, called a frenotomy.</span></figcaption>
</figure>
<h2>What is tongue tie?</h2>
<p>A frenulum is any connective tissue fold that tethers or anchors mobile organs in the body. The frenula of the tongue or upper lip in babies have a wonderful diversity of thicknesses, lengths, points of insertion, and elasticity. They tether the tongue to the floor of the mouth, and the upper lip to the gum.</p>
<p>The diagnosis of tongue tie was traditionally reserved for membrane-like tissue connecting the under-surface of the tongue to the lower gum-line, or somewhere behind it, and causing visible restriction of the tongue’s movement. </p>
<p>Midwives have long recognised that infant tongue tie can result in nipple pain for the mother and breastfeeding failure unless promptly snipped. </p>
<p>But from the 1950s, with the medicalisation of birth and the breakdown of traditional breastfeeding support, classic tongue tie was often left untreated. </p>
<p>The trend of over-treatment began in 2004, when a new diagnosis of “posterior” or “submucosal” (deep in the mouth and not easily visible) tongue tie was proposed in an <a href="http://jgh.ca/uploads/breastfeeding/aaptonguetie2004.pdf">American Academy of Pediatrics newsletter</a> and then widely promoted in lactation circles. More recently, the diagnosis of “upper lip tie” has been added to the list. </p>
<p>Today, “tight” frenula are commonly diagnosed if a breastfeeding mother has nipple pain or bouts of mastitis, or if the baby has difficulty attaching to the breast, or fusses or pulls off the breast, or clicks and splutters during feeds, or gains weight poorly, or has <a href="http://www.drscottsiegel.com/apps/blog/categories/show/1877960-patient-stories-tongue-and-lip-tie">reflux or wind</a>. </p>
<p>The baby may then be referred to the dentist or surgeon for deep laser or scissors “release”.</p>
<p>In some circles, only pointy tongues that extend to beyond the lower lip are deemed as safe. This unusual degree of tongue mobility has become the new gold standard, and shorter, squarer tongues with less elastic frenula are viewed as failures. </p>
<h2>What does the research say?</h2>
<p>Definitions aren’t agreed upon, but it’s useful to define a frenectomy as a cut that aims to sever the entire frenulum, down to the tongue muscle or gum. </p>
<p>A frenotomy, then, is a simpler snip that removes a congenital membrane from in front of the frenulum, but doesn’t aim to remove the frenulum in its entirety. </p>
<p>Two recent systematic reviews have examined the effectiveness of frentomies and frenectomies. </p>
<p><a href="http://pediatrics.aappublications.org/content/pediatrics/early/2015/04/28/peds.2015-0658.full.pdf">The first</a>, from 2014, concludes that half of breastfeeding babies with tongue-tie will not have problems. If there are difficulties, mothers report improvements after frenotomies or frenectomies. But it’s difficult to determine how much of the effect is a placebo. </p>
<p>The other review, <a href="http://adc.bmj.com/content/early/2014/11/07/archdischild-2014-306211.abstract?ct=ct">published in 2015</a>, concludes there is a small body of evidence to suggest frenotomies or frenectomies may be associated with the mother reporting improvements in breastfeeding and nipple pain. But researchers say the strength of this evidence is low to insufficient. </p>
<p>Based on the research evidence, Australia’s National Health and Medical Research Council’s (NHMRC) <a href="https://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/n56_infant_feeding_guidelines_150917.pdf">2012 Infant Feeding Guidelines</a> state: </p>
<blockquote>
<p>There is limited evidence that “tongue tie” occurs in appropriately 4-10% of healthy newborn infants (Evidence Grade D). There is limited evidence (Evidence Grade D) to suggest that infants with “tongue tie” more commonly experience breastfeeding difficulties.</p>
</blockquote>
<p>(Level D evidence is of very low quality, based on no direct research evidence or with very uncertain estimate of effect.)</p>
<p>The NHMRC <a href="https://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/n56_infant_feeding_guidelines_150917.pdf">concludes</a>:</p>
<blockquote>
<p>while surgical management of tongue-tie has been tried… further controlled trials are required.</p>
</blockquote>
<p>Other guidelines were written prior to the rise of “posterior” and “upper lip-ties” (such as the <a href="http://www.bfmed.org/Media/Files/Protocols/ankyloglossia.pdf">Academy of Breastfeeding Medicine 2004</a>, <a href="https://www.nice.org.uk/guidance/ipg149">National Institute for Health and Care Excellence 2005</a>) or lean heavily on uncertain definitions and <a href="http://www.ncbi.nlm.nih.gov/pubmed/17276561">unreliable clinical tools</a>, such as the Hazelbaker Assessment of Lingual Frenulum Function (ATLFF)).</p>
<p>Our guidelines aren’t very helpful because of serious problems in the existing research. The nature of the tongue tie, associated breastfeeding difficulties and type of surgical intervention are poorly defined, as is the kind of breastfeeding support offered alongside the surgery.</p>
<p>We need long-term follow-up studies, including research that compares the effects of these procedures with high-quality breastfeeding support over time. </p>
<h2>My clinical practice</h2>
<p>In the absence of workable guidelines, clinicians such as myself have to fall back on <a href="http://www.pameladouglas.com.au/sites/default/files/pdfs/Douglas%20BFM%202013.pdf">theoretical frames and clinical experience</a>. </p>
<p>In the clinic, I perform an oral assessment on babies who’ve been diagnosed with tongue and lip ties and whose parents want a second opinion. I do a simple frenotomy on any who have a classic tongue tie. </p>
<p>There are very occasionally babies with an unusual kind of classic tongue tie, best referred on to oral surgeons. </p>
<p>Mostly, I observe normal, if highly variable, tongue and upper lip frenula, attached to adequately mobile tongues and springy upper lips, all perfectly suitable for breastfeeding. </p>
<p>When I perform comprehensive breastfeeding assessments on babies with breastfeeding problems or fussiness, including those who’ve had oral surgery in the previous weeks or months, I find a range of underlying problems that have not been properly identified and addressed, though the women have usually seen multiple health professionals. </p>
<p>I regularly see babies who have become even fussier at the breast after they’ve had the deep laser or scissor cuts and the distressing wound-stretching exercises. We call this “oral aversion”. </p>
<p>Occasionally, I find other unexpected side-effects of frenectomies: an under-surface of a tongue partly separated into two, or stitches inserted under the baby’s tongue, or into the upper gum. Parents are told the stitches were because the tie was so bad. But stitches are only put in to control excessive bleeding. </p>
<p>My colleagues and I then offer our “gestalt” breastfeeding intervention – that is, our focused fit and hold work with mothers and infants, integrated with our <a href="http://www98.griffith.edu.au/dspace/bitstream/handle/10072/56075/88980_1.pdf?sequence=1">evidence-based approach</a> to unsettled infant behaviour. </p>
<p>In our experience, with the right help, the feeding difficulties and unmanageable fussiness usually resolve. </p>
<h2>Support for breastfeeding women</h2>
<p><a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2815%2901024-7/abstract">Breastfeeding offers</a> substantial short- and long-term health benefits to both mother and child. </p>
<p>Yet clinical breastfeeding support is not prioritised within the overcrowded primary health care agenda, and primary health care research is not prioritised within the national health research agenda. </p>
<p>In the meantime, parents can feel comfortable that a simple frenotomy for a classic tongue tie just as soon as possible after birth is likely to protect breastfeeding and, if severe, speech and oral hygiene down the track. </p>
<p>If the baby has been referred for deep surgical cuts due to a diagnosis of tongue and upper lip tie, it’s worth getting a second opinion from a GP or paediatrician with special interest in breastfeeding. </p>
<p><em>A longer essay on this issue is published this week in the <a href="https://griffithreview.com/articles/tongues-tied-about-tongue-tie/">Griffith Review</a>.</em></p><img src="https://counter.theconversation.com/content/54040/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pamela S Douglas is medical director of the non-profit Possums Clinic <a href="http://www.possumsonline.com">www.possumsonline.com</a>. Evaluation of the Possums approach to unsettled infant behaviour was funded by The RACGP Foundation and the Queensland Centre for Mothers and Babies. </span></em></p>Breastfed infants diagnosed with “tongue tie” are being unnecessarily treated with deep laser or scissors cuts under both their tongue and upper lip in the first weeks and months of life.Pamela S Douglas, General Practitioner, Researcher, Writer, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/442172015-07-07T09:00:01Z2015-07-07T09:00:01ZThat neat and tidy map of tastes on the tongue you learned in school is all wrong<p>Everybody has seen the tongue map – that little diagram of the tongue with different sections neatly cordoned off for different taste receptors. Sweet in the front, salty and sour on the sides and bitter at the back. </p>
<p>It’s possibly the most recognizable symbol in the study of taste, but it’s wrong. In fact, it was debunked by chemosensory scientists (the folks who study how organs, like the tongue, respond to chemical stimuli) long ago. </p>
<p>The ability to taste sweet, salty, sour and bitter isn’t sectioned off to different parts of the tongue. The receptors that pick up these tastes are actually distributed all over. We’ve known this for a long time.</p>
<p>And yet you probably saw the map in school when you learned about taste. So where did it come from?</p>
<h2>Origins of the taste map</h2>
<p>That familiar but not-quite-right map has its roots in a 1901 paper, <a href="http://books.google.com/books?id=FmAUAQAAIAAJ&pg=PA1#v=onepage&q&f=false">Zur Psychophysik des Geschmackssinnes</a>, by German scientist David P Hänig. </p>
<p>Hänig set out to measure the thresholds for taste perception around the edges of the tongue (what he referred to as the “taste belt”) by dripping stimuli corresponding to salty, sweet, sour and bitter tastes in intervals around the edges of the tongue. </p>
<p>It is true that the tip and edges of the tongue are particularly sensitive to tastes, as these areas contain many tiny sensory organs called taste buds.</p>
<p>Hänig found that there was some variation around the tongue in how much stimulus it took for a taste to register. Though his research never tested for the now-accepted fifth basic taste, umami (the savory taste of glutamate, as in monosodium glutamate or MSG), Hänig’s hypothesis generally holds up. Different parts of the tongue do have a lower threshold for perceiving certain tastes, but these differences are rather minute. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/87245/original/image-20150703-11301-1v6p8ii.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/87245/original/image-20150703-11301-1v6p8ii.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1023&fit=crop&dpr=1 600w, https://images.theconversation.com/files/87245/original/image-20150703-11301-1v6p8ii.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1023&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/87245/original/image-20150703-11301-1v6p8ii.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1023&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/87245/original/image-20150703-11301-1v6p8ii.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1285&fit=crop&dpr=1 754w, https://images.theconversation.com/files/87245/original/image-20150703-11301-1v6p8ii.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1285&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/87245/original/image-20150703-11301-1v6p8ii.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1285&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The taste map: 1. Bitter 2. Sour 3. Salt 4. Sweet.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Taste_buds.svg">MesserWoland via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The problem isn’t with Hänig’s findings. It’s how he decided to present that information. When Hänig published his results, he included a line graph of his measurements. The graph plots the relative change in sensitivity for each taste from one point to the next, not against other tastes. </p>
<p>It was more of an artistic interpretation of his measurements than an accurate representation of them. And that made it look as though different parts of the tongue were responsible for different tastes, rather than showing that some parts of the tongue were slightly more sensitive to certain tastes than others.</p>
<p>But that artful interpretation still doesn’t get us to the taste map. For that, we need to look to Edwin G Boring. In the 1940s, this graph was reimagined by Boring, a Harvard psychology professor, in his book <a href="http://www.researchgate.net/publication/232480794_Sensation_and_perception_in_the_history_of_experimental_psychology">Sensation and Perception in the History of Experimental Psychology</a>. </p>
<p>Boring’s version also had no meaningful scale, leading to each taste’s most sensitive area being sectioned off in what we now know as the tongue map.</p>
<h2>Long in dispute</h2>
<p>In the decades since the tongue map was created, many researchers have refuted it.</p>
<p>Indeed, results from a number of experiments indicate that all areas of the mouth containing taste buds – including several parts of the tongue, the soft palate (on the roof of your mouth) and the throat – are sensitive to all taste qualities. </p>
<p>Our understanding of how taste information is carried from the tongue to the brain shows that individual taste qualities are not restricted to a single region of the tongue. There are two cranial nerves responsible for taste perception in different areas of the tongue: the glossopharyngeal nerve in the back and the chorda tympani branch of the facial nerve in the front. If tastes were exclusive to their respective areas, then damage to the chorda tympani, for instance, would take away one’s ability to taste sweet.</p>
<p>In 1965, surgeon TR Bull <a href="https://www.researchgate.net/publication/231967815_Taste_and_the_Chorda_Tympani">found that</a> subjects who had had their chorda tympani cut in medical procedures also reported no loss of taste. And in 1993, Linda Bartoshuk from the University of Florida <a href="http://www.researchgate.net/publication/240429854_The_biological_basis_of_food_perception_and_acceptance">found that</a> by applying anesthesia to the chorda tympani nerve, not only could subjects still perceive a sweet taste, but they could taste it even more intensely. </p>
<h2>Molecular biologists weigh in</h2>
<p>Modern molecular biology also argues against the tongue map. Over the past 15 years, researchers <a href="http://dx.doi.org/10.1146/annurev.nutr.26.061505.111329">have identified</a> <a href="http://dx.doi.org/10.1038/35007072">many</a> of the <a href="http://dx.doi.org/10.1016/S0092-8674(00)80658-3">receptor</a> <a href="http://dx.doi.org/10.1016/S0092-8674(00)80706-0">proteins</a> found on taste cells in the mouth that are critical for detecting taste molecules. </p>
<p>For example, we now know that everything that we perceive to be sweet can activate the same receptor, while bitter compounds activate a completely different type of receptor. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/87246/original/image-20150703-11318-rzpqn2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/87246/original/image-20150703-11318-rzpqn2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/87246/original/image-20150703-11318-rzpqn2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/87246/original/image-20150703-11318-rzpqn2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/87246/original/image-20150703-11318-rzpqn2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/87246/original/image-20150703-11318-rzpqn2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/87246/original/image-20150703-11318-rzpqn2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">You taste with your whole tongue.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-221859838/stock-photo-adorable-little-boy-helping-and-baking-apple-pie-in-home-s-kitchen-indoor-tasting-vanilla-dough.html?src=dj0dHDKj5k5SNMjT60xCag-2-29">Boy via www.shutterstock.com.</a></span>
</figcaption>
</figure>
<p>If the tongue map were correct, one would expect sweet receptors to be localized to the front of the tongue and bitter receptors restricted to the back. But this is not the case. Rather, each receptor type is found across all taste areas in the mouth.</p>
<p>Despite the scientific evidence, the tongue map has burrowed its way into common knowledge and is still taught in many classrooms and textbooks today.</p>
<p>The true test doesn’t require a laboratory, though. Brew a cup of coffee. Crack open a soda. Touch a salted pretzel to the tip of the tongue. In any test, it becomes clear the tongue can perceive these tastes all over.</p>
<hr>
<p><em>This piece was coauthored by Drew Wilson, communications specialist at the University of Florida Center for Smell and Taste.</em></p><img src="https://counter.theconversation.com/content/44217/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steven D Munger receives funding from the National Institute on Deafness and Other Communication Disorders.</span></em></p>We can thank scholarly misinterpretation for the well-known but inaccurate map of the tongue.Steven D. Munger, Associate Director, Center for Smell and Taste; Professor of Pharmacology and Therapeutics, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/396482015-04-02T09:07:41Z2015-04-02T09:07:41ZGeographic tongue: the mysterious condition that makes maps in your mouth<figure><img src="https://images.theconversation.com/files/76778/original/image-20150401-31316-1rxs876.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What in the world ..?</span> <span class="attribution"><a class="source" href="http://en.wikipedia.org/wiki/Geographic_tongue#/media/File:Geographic_tongue_(cropped).jpg">Jbarta</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Geographic tongue (GT) is a medical condition in which the upper layer of the tongue, which consists of tiny hair-like protrusions (called papillae), is damaged due to an expanding inflammation. As a result, red patches devoid of papillae can be observed on the surface of the tongue. A noticeable characteristic of the condition is an evolving map-like appearance of the affected tongue (hence its name). </p>
<p>GT, which is harmless and affects <a href="http://www.aaomp.org/public/geographic-tongue.php">about 2%</a> of the population, was first reported more than 180 years ago. It has been investigated ever since, but the actual cause of the condition remains unknown. GT has been associated with different diseases <a href="http://www.ncbi.nlm.nih.gov/pubmed/16487088">such as psoriasis</a>.</p>
<h2>Maps and maths</h2>
<p>In <a href="http://iopscience.iop.org/1367-2630/17/3/033049">a recent investigation</a>, published in New Journal of Physics, we treated GT <a href="http://mathinsight.org/dynamical_system_idea">as a dynamical system</a> – a mathematical description that enables one to examine how something evolves over time – that consists of a large number of coupled (interacting) elements such as the hair protrusions. Each of these elements can be found in one of three states: a healed (unaffected) state, an excited state and a recovering state. Once an element is excited, it then goes through a remission period in which it cannot be excited. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/76782/original/image-20150401-31268-1ojyo2q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/76782/original/image-20150401-31268-1ojyo2q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/76782/original/image-20150401-31268-1ojyo2q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/76782/original/image-20150401-31268-1ojyo2q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/76782/original/image-20150401-31268-1ojyo2q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/76782/original/image-20150401-31268-1ojyo2q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/76782/original/image-20150401-31268-1ojyo2q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Excited element: the trees.</span>
<span class="attribution"><span class="source">Forest fire by Shutterstock</span></span>
</figcaption>
</figure>
<p>Other well-known natural phenomena that can be treated in this manner include the heart muscle (where the cardiac cells are the coupled elements) and forest fires (where the trees are the elements) – once a fire has started, it then moves to fresh areas until it has burned everywhere that it can. The forest then enters a long recovering period and eventually completely recovers. Systems that can be described in this way fall in the category of “excitable media”. </p>
<p>A similar process also happens with GT. But as it is a chronic condition, it will reoccur at a later time. By identifying GT as a novel example of excitable media dynamics, we were able to examine and visualise the evolution of the condition using numerical simulations. </p>
<h2>Swirls and movement</h2>
<p>Taking a dynamical systems approach to GT enabled us to classify the severity of the condition, based on the patterns observed on the tongue of a GT patient. Typically GT-affected tongues fall into two main categories. The first corresponds to oblate patterns that expands and merges with other growing oblate regions. In this case, like with forest fires, the tongue is gradually affected but then subsequently heals. Another more “exotic” form of the condition involves patterns consisting of open-ended tips, most notably spirals, which can evolve into the recovering regions of the tongue. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/76779/original/image-20150401-31292-17dh1dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/76779/original/image-20150401-31292-17dh1dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=730&fit=crop&dpr=1 600w, https://images.theconversation.com/files/76779/original/image-20150401-31292-17dh1dc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=730&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/76779/original/image-20150401-31292-17dh1dc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=730&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/76779/original/image-20150401-31292-17dh1dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=917&fit=crop&dpr=1 754w, https://images.theconversation.com/files/76779/original/image-20150401-31292-17dh1dc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=917&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/76779/original/image-20150401-31292-17dh1dc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=917&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Like a forest fire.</span>
<span class="attribution"><a class="source" href="http://en.wikipedia.org/wiki/Geographic_tongue#/media/File:Landkartenzunge_005.jpg">Bin im Garten</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>As the spiral pattern evolves, its arm rotates and continuously affects recovering regions. This self-sustaining characteristic might hinder the tongue from healing and so cause a more acute condition, which will linger for longer periods of time before the tongue is completely healed.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/76790/original/image-20150401-31299-10e2zwl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/76790/original/image-20150401-31299-10e2zwl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=604&fit=crop&dpr=1 600w, https://images.theconversation.com/files/76790/original/image-20150401-31299-10e2zwl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=604&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/76790/original/image-20150401-31299-10e2zwl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=604&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/76790/original/image-20150401-31299-10e2zwl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=758&fit=crop&dpr=1 754w, https://images.theconversation.com/files/76790/original/image-20150401-31299-10e2zwl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=758&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/76790/original/image-20150401-31299-10e2zwl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=758&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Spiral by Shutterstock</span></span>
</figcaption>
</figure>
<p>GT is a mysterious condition but we hope that this novel approach will help physicians to assess patients with GT condition and trigger further clinical investigations, particularly into how and why GT patterns form and move around. We might then learn more about the underlying mechanism responsible for this disease.</p><img src="https://counter.theconversation.com/content/39648/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gabriel Seiden does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Say ahhh. How mathematicians are looking at a baffling tongue condition that spirals around your tongue.Gabriel Seiden, Physicist, Weizmann Institute of ScienceLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/305042014-09-14T20:21:13Z2014-09-14T20:21:13ZAbhor asparagus and can’t stand coffee? You may be a supertaster<figure><img src="https://images.theconversation.com/files/58517/original/pjrbwx3z-1410234330.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If some foods weird out your taste buds, read on to see if you fall in the 'supertaster' quarter of the population.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/parkydoodles/3473249591">parkydoodles/Flickr (cropped)</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>There are natural variations between humans in our senses. We need different prescriptions to correct our eyesight. Some people say that <a href="http://electronics.howstuffworks.com/question487.htm">vinyl sounds better</a> than CDs or MP3s and will pay <a href="http://www.cnet.com/au/how-to/who-needs-expensive-audio-cables/">big money</a> for audio equipment, while others can’t tell the difference.</p>
<p>So what about taste and smell? Many of us have heard of supertasters, but why – and how – do they exist? And how can you tell if you’re one too?</p>
<p>Strictly speaking, the word “taste” refers to the five primary tastes: sweet, sour, bitter, salty and umami. </p>
<p>There is some evidence for other primary tastes, with <a href="http://www.washingtonpost.com/national/health-science/fat-might-be-the-sixth-basic-taste/2012/06/04/gJQAt218DV_story.html">fat</a> most likely to be the next to be recognised. Others include <a href="http://www.nature.com/srep/2012/120706/srep00496/full/srep00496.html">calcium</a> and metallic, although the latter is often due to various <a href="http://www.buzzle.com/articles/what-causes-metal-taste-in-mouth.html">disorders or conditions</a>.</p>
<p>It’s the bitter taste that started all of this supertaster stuff. In 1931, American chemist Arthur Fox accidentally released a cloud of phenylthiocarbamide (<a href="http://www.britannica.com/EBchecked/topic/455706/phenylthiocarbamide-tasting">PTC</a>) powder into his laboratory. Some of this cloud went into Fox’s mouth, and that of one of his colleagues. His colleague complained that it tasted intensely bitter, while Fox tasted nothing.</p>
<p>They tasted it again, with the same result. Fox went on to get others to taste PTC. He <a href="http://learn.genetics.utah.edu/content/inheritance/ptc/">found</a> that some found it intensely bitter, some mildly bitter, and others could not taste anything.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/58523/original/ytqyjvcp-1410235128.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58523/original/ytqyjvcp-1410235128.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/58523/original/ytqyjvcp-1410235128.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58523/original/ytqyjvcp-1410235128.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58523/original/ytqyjvcp-1410235128.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58523/original/ytqyjvcp-1410235128.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58523/original/ytqyjvcp-1410235128.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58523/original/ytqyjvcp-1410235128.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="http://www.flickr.com/photos/53817483@N00/2940626958">dogtooth77/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>These differences in perception are partly due to the nature of the receptors in your mouth, which differ <a href="http://health.howstuffworks.com/mental-health/human-nature/perception/taste4.htm">depending on your genes</a>. The <a href="http://udel.edu/%7Emcdonald/mythptc.html">gene</a> that codes for the PTC receptor exists in two common forms (and a few rare forms), which result in bitterness proteins with slightly different shapes. This, in turn, has an effect on how sensitive you are to bitterness – but that’s not the end of the story.</p>
<h2>The term ‘supertaster’ is born</h2>
<p>These days, chemosensory scientists use 6-n-propylthiouracil (<a href="http://chemse.oxfordjournals.org/content/26/1/41.full">PROP</a> or PTU) instead of PTC. PTC is a <a href="http://www.nature.com/nature-newbio/journal/v235/n55/pdf/newbio235093a0.pdf">little bit toxic</a>, so beware of taste and smell scientists such as Fox approaching you and asking you to “taste this”.</p>
<p>In 1991, American psychologist <a href="http://www.psychologicalscience.org/index.php/video/inside-the-psychologists-studio-linda-bartoshuk.html">Linda Bartoshuk</a> conducted experiments using PROP. She coined the term “supertasters” for people who found PROP intensely bitter, and the term stuck.</p>
<p>During these experiments, Bartoshuk noticed that these supertasters had a more dense covering of structures that contain taste buds (known as <a href="http://link.springer.com/chapter/10.1007%2F978-4-431-68355-1_12">fungiform papillae</a>) on their tongue. She concluded that the number of receptors is important, too. You can actually use this information to <a href="http://www.bbc.co.uk/science/0/22941835">test</a> if you are a supertaster.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/58513/original/rr27c3k5-1410228587.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58513/original/rr27c3k5-1410228587.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/58513/original/rr27c3k5-1410228587.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=495&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58513/original/rr27c3k5-1410228587.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=495&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58513/original/rr27c3k5-1410228587.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=495&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58513/original/rr27c3k5-1410228587.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=621&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58513/original/rr27c3k5-1410228587.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=621&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58513/original/rr27c3k5-1410228587.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=621&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">By using food dye, count the number of taste buds in an area the size of a hole punch to see if you’re a supertaster.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/cookingforgeeks/3927821426">Jeff Potter/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Fewer than 15 tastebuds in an area the size of a hole punch indicates a “non-taster”, between 15 and 35 means you fall in the average range, while if you have more than 35 tastebuds in that area, you’re a supertaster.</p>
<p>About one in four of us is a supertaster, one in four is a non-taster (such as Fox) and the rest of us are “medium” or “average” tasters. The proportions vary a little by <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3953580/">culture</a> and there is some variation within each group.</p>
<p>Supertasting is not restricted to bitterness. Supertasters often report that sweet or sour tastes are <a href="https://www.inkling.com/read/cooking-for-geeks-jeff-potter-1st/chapter-3/differences-in-taste-and">more intense</a>. Salt appears to be a bit of a <a href="http://www.ncbi.nlm.nih.gov/pubmed/20380843">different beast</a> – it seems that supertasters actually consume more salt, possibly because it masks bitterness.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/58521/original/vnhcjd33-1410234757.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58521/original/vnhcjd33-1410234757.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/58521/original/vnhcjd33-1410234757.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=901&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58521/original/vnhcjd33-1410234757.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=901&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58521/original/vnhcjd33-1410234757.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=901&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58521/original/vnhcjd33-1410234757.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1132&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58521/original/vnhcjd33-1410234757.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1132&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58521/original/vnhcjd33-1410234757.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1132&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="http://www.flickr.com/photos/tudor/3711184394">TheGiantVermin/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>You may already have an inkling if you are a supertaster based on the foods that you like. If you find <a href="https://www.researchgate.net/publication/22044422_PTC_taste_blindness_and_the_taste_of_caffeine">coffee</a> too bitter for your tastes, you may be a supertaster. </p>
<p>You may be <a href="http://www.tufts.edu/home/feature/?p=tasters&p2=2">thinner</a> because you have a healthier diet. This is because you avoid sugar and fat (although this all depends on what you consider a healthy diet to be – there seems to be a <a href="http://greatist.com/health/saturated-fat-healthy">new</a> <a href="http://authoritynutrition.com/10-disturbing-reasons-why-sugar-is-bad/">story</a> <a href="http://www.lifetimetv.co.uk/features/why-sugar-is-good-for-you">every</a> <a href="http://www.theguardian.com/lifeandstyle/2014/mar/23/everything-you-know-about-unhealthy-foods-is-wrong">week</a>).</p>
<p>But being a supertaster might also put you off <a href="http://www.mindthesciencegap.org/2013/04/05/hate-vegetables-blame-it-on-your-supertaste-gene/">healthy bitter foods</a>, such as broccoli, Brussels sprouts or asparagus. </p>
<p>While bitterness is important for some foods (such as chocolate), we generally reject bitter foods because <a href="http://www.eurekalert.org/pub_releases/2006-09/mcsc-bti091206.php">poisonous things</a> are usually bitter. At least <a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=nutrigenomics+of+taste+-+impact+of+food+preferences">one study</a> suggests that supertasters do indeed eat fewer bitter vegetables.</p>
<p>Fortunately for asparagus farmers, scientists have <a href="http://www.dailymail.co.uk/health/article-167645/Bitter-taste-veg-disguised.html">developed</a> “<a href="http://www.novotaste.com/content/bitter-blockers">bitter blockers</a>”. So, kids of the world, you may not be able to use the supertaster excuse for avoiding your vegetables. Parents – thank me later. Kids – my sincere apologies.</p>
<h2>Are there supersmellers?</h2>
<p>We have five (or so) primary tastes, but there doesn’t seem to be such a thing as a primary smell. Instead, our olfactory system can discriminate between thousands of different smells due to loads of <a href="http://mbe.oxfordjournals.org/content/20/3/307">different receptors</a>, all coded for by specific genes.</p>
<p>Different people have different genes. Given the number of different types of receptors involved, the chances of having dinner with someone with the same set of receptors as you are quite low.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/58515/original/2pckrh36-1410230055.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58515/original/2pckrh36-1410230055.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/58515/original/2pckrh36-1410230055.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58515/original/2pckrh36-1410230055.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58515/original/2pckrh36-1410230055.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58515/original/2pckrh36-1410230055.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58515/original/2pckrh36-1410230055.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58515/original/2pckrh36-1410230055.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Shiraz and pepper both contain rotundone.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/roland/159712541">Roland Tanglao/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Just like Fox and co’s different experiences of PTC, our experiences of smell (and therefore our <a href="http://neuroscience.uth.tmc.edu/s2/chapter09.html">perceptions of flavour</a>) vary. </p>
<p><a href="http://en.wikipedia.org/wiki/Rotundone">Rotundone</a> is the main chemical responsible for the smell of pepper (called a <em>character impact odorant</em>). It’s pretty strong and yet about 25% of the population can’t detect it at all, while still being able to detect other smells.</p>
<p>Rotundone is an interesting case because it’s also present in many wines made from the grape <a href="https://home.zhaw.ch/yere/pdf/Teil121%20-%20Expression%20of%20Multidisciplinary.pdf">Shiraz</a> (or Syrah). These wines are often noted for their spicy or peppery characteristics. So when wine experts describe a Shiraz as peppery, they’re not making it up – it contains the same chemical as pepper.</p>
<p>So are some people more sensitive to smell? <a href="http://ask.metafilter.com/82497/Im-just-too-scentsitive">Sure</a>, just as some are more sensitive to taste, to light (such as Bono, who claims to have <a href="http://news.yahoo.com/blogs/the-difference/behind-sunglasses-bono-eyewear-explained-165303304.html">sensitive eyes</a>) and to other stimuli.</p>
<p>Our senses of taste and smell are essentially little chemistry labs that conduct loads of experiments to determine which chemicals are present in food, drinks and air. But not all chemistry labs are created equal – some of us have equipment that others don’t have and can therefore detect different chemicals. And for some of us, our equipment is more sensitive. </p>
<p>So next time you’re having an argument with someone over dinner about whether the meal is any good, keep in mind that their experience is probably very different to yours.</p><img src="https://counter.theconversation.com/content/30504/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alex Russell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There are natural variations between humans in our senses. We need different prescriptions to correct our eyesight. Some people say that vinyl sounds better than CDs or MP3s and will pay big money for…Alex Russell, PhD Student and Research Affiliate, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/299352014-07-31T05:05:37Z2014-07-31T05:05:37ZExplainer: why do snakes flick their tongues?<figure><img src="https://images.theconversation.com/files/55331/original/nkr7j8zb-1406733816.jpg?ixlib=rb-1.1.0&rect=1%2C136%2C1022%2C657&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Speaks with a forked tongue.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/pcoin/2307912302">pcoin</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Many people think a snake’s forked tongue is creepy. Every so often, the snake waves it around rapidly, then retracts it. Theories explaining the forked tongues of snakes have been around for thousands of years. <a href="http://books.google.com/books?id=HeB7AAAAQBAJ&pg=PT1303&lpg=PT1303&dq=a+twofold+pleasure+from+savours,+their+gustatory+sensation+being+as+it+were+doubled&source=bl&ots=rnf4HucLSq&sig=XhMjT8qihAzNVFrx5XqQ2eEnpf4&hl=en&sa=X&ei=3uOqU9ylMZWuyATs24HADQ&ved=0CCYQ6AEwAQ#v=onepage&q=a%20twofold%20pleasure%20from%20savours%2C%20their%20gustatory%20sensation%20being%20as%20it%20were%20doubled&f=false">Aristotle reasoned</a> that it provided snakes with “a twofold pleasure from savours, their gustatory sensation being as it were doubled”. </p>
<p>Italian astronomer <a href="http://books.google.com/books?id=YmtBCG4CX10C&pg=PA44&lpg=PA44&dq=%22for+picking+the+Dirt+out+of+their+Noses,+which+would+be+apt+else+to+stuff+them,+since+they+are+always+grovelling+on+the+Ground,+or+in+Caverns+of+the+Earth&source=bl&ots=zCS-mwtfpu&sig=TZNtV-0qik23FHpRlD3RT-2Bhzk&hl=en&sa=X&ei=0V2rU6CiMYi_8QGqiIHICg&ved=0CB8Q6AEwAA#v=onepage&q=%22for%20picking%20the%20Dirt%20out%20of%20their%20Noses%2C%20which%20would%20be%20apt%20else%20to%20stuff%20them%2C%20since%20they%20are%20always%20grovelling%20on%20the%20Ground%2C%20or%20in%20Caverns%20of%20the%20Earth&f=false">Giovanni Hodierna thought</a> snake tongues were for cleaning dirt out of their noses. Some 17th century writers claimed to have watched snakes <a href="http://books.google.com/books?id=ijblNZQrk_wC&pg=PA397&lpg=PA397&dq=klauber+rattlesnakes+with+wonderful+nimbleness&source=bl&ots=CCeXoKwxAp&sig=UlM9Nv44r7yUJxJ_XfDIMzIDhxI&hl=en&sa=X&ei=oOOqU-qbGMmlyAStzIB4&ved=0CCAQ6AEwAQ#v=onepage&q=klauber%20rattlesnakes%20with%20wonderful%20nimbleness&f=false">catch flies or other animals</a> between the forks of their tongues, using them like forceps. It is a common myth even today that snakes can sting you with their tongues. But none of those hypotheses is likely.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/1znjYlysQys?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Most animals with tongues use them for tasting, to clean themselves or others, or to capture or manipulate their prey. A few, including humans, also use them to make sounds. Snakes do not use their tongues for any of these things. Over the past 20 years, <a href="http://scholar.google.com/citations?user=G-2IS0oAAAAJ&hl=en">Kurt Schwenk</a>, an evolutionary biologist at the University of Connecticut, has been working on understanding the function of snake tongues, and “smelling” is the closest description of what snakes do with their tongues.</p>
<h2>Tongues that smell</h2>
<p>Snakes use their tongues for collecting chemicals from the air or ground. The tongue does not have receptors to taste or smell. Instead, these receptors are in the vomeronasal, or Jacobson’s Organ, which is in the roof of the mouth. Once inside the Jacobson’s Organ, different chemicals evoke different electrical signals which are relayed to the brain.</p>
<p>It was once thought that the tongue delivered chemicals directly to the Jacobson’s Organ, because both the organ and the pathways that lead to it are paired just like the tips of the tongue. But <a href="http://booksandjournals.brillonline.com/content/journals/10.1163/156853890x00186">X-ray movies have revealed</a> that the tongue does not move inside the closed mouth, it simply deposits the chemicals it has collected onto pads on the floor of the mouth as the mouth is closing. </p>
<p>It is <a href="http://psycnet.apa.org/journals/com/111/3/302/">most likely</a> that these pads deliver the sampled molecules to the entrance of the Jacobson’s Organ when the floor of the mouth is elevated to come into contact with the roof following a tongue flick. The case for this is strengthened because geckos, skinks, and other lizards lack deeply-forked tongues but still deliver chemicals to their vomeronasal organs.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/55340/original/zqfhf3ss-1406737618.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55340/original/zqfhf3ss-1406737618.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55340/original/zqfhf3ss-1406737618.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55340/original/zqfhf3ss-1406737618.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55340/original/zqfhf3ss-1406737618.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55340/original/zqfhf3ss-1406737618.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55340/original/zqfhf3ss-1406737618.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/coloneljohnbritt/10129968285/">coloneljohnbritt</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<h2>Smelling in 3-D</h2>
<p>Because it is forked, the tongue of a snake can collect chemical information from two different places at once, albeit places that are fairly close together by human standards. When snakes spread the tips of their tongues apart, the distance can be twice as wide as their head. This is important because it allows them to detect chemical gradients in the environment, which gives them a sense of direction – in other words, snakes use their forked tongues to help them smell in three dimensions. Owls use their asymmetrical ears <a href="http://www.stanford.edu/group/stanfordbirds/text/essays/How_Owls_Hunt.html">in this way</a> to detect sound in three dimensions. </p>
<p>Snakes and owls use similar neural circuitry to compare the signal strength delivered from each side of the body and determine the direction that a smell or a sound is coming from. Humans do this with their hearing too, but not as effectively. </p>
<p>This makes it possible for snakes to follow trails left by their prey or potential mates. In the 1930s, before guidelines on the ethical use of animals in research were as strict, German biologist Herman Kahmann experimentally removed the forked part of snakes’ tongues and found that they could still respond to smells, but that they had lost their ability to follow scent trails. These results were refined and confirmed during the 1970s.</p>
<h2>Sniffing out sex</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/55336/original/bbn7b77h-1406737139.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55336/original/bbn7b77h-1406737139.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/55336/original/bbn7b77h-1406737139.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=763&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55336/original/bbn7b77h-1406737139.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=763&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55336/original/bbn7b77h-1406737139.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=763&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55336/original/bbn7b77h-1406737139.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=959&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55336/original/bbn7b77h-1406737139.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=959&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55336/original/bbn7b77h-1406737139.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=959&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tongue sizes in Copperhead snake males (left) and females (right).</span>
<span class="attribution"><a class="source" href="http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2007.00396.x/abstract">Smith et al/Journal of Zoology</a></span>
</figcaption>
</figure>
<p>In the 1980s, <a href="http://www.uttyler.edu/biology/research/ford/">snake biologist Neil Ford</a> at the University of Texas at Tyler watched how male garter snakes used their tongues when they were following pheromone trails left behind by females. He found that if both tips of the male snake’s tongue fell within the width of the trail, the snake continued slithering straight ahead. However, when one tip or the other fell outside the edge of the trail, the snake turned his head away from that tip and back towards the pheromone trail, and his body followed.</p>
<p>Following this simple rule allowed the snakes to perform trail-following behaviour that was both accurate and directed. If both tongue tips ever touched the ground outside of the trail, the male would stop and swing his head back and forth, tongue-flicking, until he relocated the trail. </p>
<p>Snake ecologist <a href="http://sites.wofford.edu/smithcf/">Chuck Smith</a> at Wofford College found evidence that male Copperheads <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2007.00396.x/abstract">have longer, more deeply-forked tongues than females</a>, which presumably enhances their ability to find mates. Although <a href="http://snakesarelong.blogspot.com/2013/02/malagasy-leaf-nosed-snakes.html">sexual dimorphism</a> – where one sex is markedly different from the other – is rare in snakes, differences in tongue size are likely to be present in other species as well.</p>
<p>Scent-trailing is probably also quite helpful to snakes tracking down prey, including for sit-and-wait predators like vipers, which have evolved <a href="http://snakesarelong.blogspot.com/2013/03/non-toxic-venoms.html">smelly but non-toxic venom components</a> to help them relocate their bitten and envenomated prey.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/55338/original/gymsdjm7-1406737324.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55338/original/gymsdjm7-1406737324.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/55338/original/gymsdjm7-1406737324.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=916&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55338/original/gymsdjm7-1406737324.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=916&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55338/original/gymsdjm7-1406737324.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=916&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55338/original/gymsdjm7-1406737324.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1152&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55338/original/gymsdjm7-1406737324.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1152&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55338/original/gymsdjm7-1406737324.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1152&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="attribution"><a class="source" href="http://chemse.oxfordjournals.org/content/37/9/883.long">Dagfhous et al/Chemical Senses</a></span>
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</figure>
<p>When following a scent-trail, snakes simply touch their tongue tips down to the ground to pick up the chemical information lying there. But <a href="http://chemse.oxfordjournals.org/content/37/9/883.long">snakes can also use a different type of tongue-flick</a> to sample airborne chemicals. </p>
<p>Snakes often wave their tongues in the air without putting them in contact with anything. The tongue creates air vortices, such as those formed in the water behind a boat. These vortices drift away from the boat as they form. <a href="http://hydrodictyon.eeb.uconn.edu/eebedia/index.php/William_Ryerson">Bill Ryerson</a>, a student in the Schwenk lab, found that vortices created in the air by snake tongues have a special property – they do not drift away but rather stay in the vicinity of the tongue, where they can be sampled repeatedly as the tongue skirts the part of each vortex where the air velocity is the highest. </p>
<p>Oscillating tongue-flicks are unique to snakes. They allow snakes to sample 100 times as much air as the simple downward extension of the tongue. The tongue then transfers these molecules to the Jacobson’s Organ via the mouth floor. Evidence suggests that male Copperheads can also find and follow females <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2007.00396.x/abstract">using oscillating tongue-flicks</a> to detect airborne pheromones, although the details of how they determine direction using such dispersed and transient odours are still poorly understood. </p><img src="https://counter.theconversation.com/content/29935/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Durso does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Many people think a snake’s forked tongue is creepy. Every so often, the snake waves it around rapidly, then retracts it. Theories explaining the forked tongues of snakes have been around for thousands…Andrew Durso, PhD student, Utah State UniversityLicensed as Creative Commons – attribution, no derivatives.