It’s electrifying: non-invasive brain stimulation

The scientific evidence for brain stimulation is only in its initial stages. Image from

A simple procedure requiring only a nine-volt battery and a few cords strapped to your head is gaining momentum with DIY types eager to improve brain function.

Brain stimulation involves weak electric currents passed into the brain through pads placed on the scalp. The electric current can alter the activity of brain cells and has the potential to improve your ability to learn.

But the evidence for brain stimulation is, so far, thin on the ground. And with no real understanding of the potential dangers of long-term use, the risks of electrical brain stimulation might outweigh the benefits.

Electrify your brain

Using a simple device, brain stimulation allows you to alter the activity of brain cells. Early research suggests that this form of brain stimulation, known as transcranial direct current stimulation, may manipulate brain plasticity and improve numeracy, reading efficiency, language learning and complex problem solving.

Apart from enhancing the healthy brain, brain stimulation may be able to help people re-learn skills lost through injury or illness. After a stroke, learning to walk again, button a coat or hold a fork can take months of intensive therapy.

If important skills could be re-learnt faster, therapy times would be shorter, people would get better quicker and health-care costs would be reduced. But the scientific evidence for brain stimulation is only in its initial stages.

All-purpose brain enhancer? Not quite

There have been many early studies designed to investigate, in principle, whether brain stimulation might work in humans. But most have only a small number of participants, and have experimental designs at high risk of bias, with no control treatment to compare to brain stimulation, investigators who were not blinded (so they knew which group was receiving which intervention), and a lack of random allocation.

We don’t yet have high-quality evidence in the form of randomised controlled trials, which are only just beginning. And although brain stimulation appears safe in the short term (the main risk is the potential for skin burns under the electrodes), long-term safety studies are yet to be completed.

This is not to say that brain stimulation doesn’t work, it’s just that there’s insufficient evidence to tell one way or the other.

But the simplicity of this technology means that early positive findings are enough for those who are keen to try enhancing their brains at home. You can find online instructions about building a brain stimulation unit of your own, and see people using the technique to improve their quiz results on YouTube. But be warned, we still don’t know the potential dangers of such use.

A DIY brain stimulation enthusiast attempts to stimulate his brain to improve his math skills.

Amidst the growing hype, a study published earlier this year highlighted the need for careful policy to ensure public safety while supporting DIY innovation, to avoid driving the practice underground.

The authors advocate “managed technological optimism” that consists of education on the potential benefits and risks of brain stimulation, open communication between DIYers and scientists and active oversight, rather than heavy government regulation.

The risks

The effects of brain stimulation depend on a complex range of factors.

The intensity of the electrical current, which part of the brain the electrodes are positioned over (you need to be sending a current to the part of the brain involved in the function you are attempting to improve) and the time that electric current is applied for can all affect results. Some applications of brain stimulation may impair, rather than enhance brain function, while increasing the application time may give long-lasting effects.

The risk? Inadvertently producing detrimental, long-lasting brain effects that are difficult to reverse.

In people with medical conditions, brain stimulation may impact negatively on other treatments or medications. And the type of brain stimulation needed to give a positive effect may differ depending on the medical condition and a person’s individual brain anatomy.

This means brain stimulation that works for one person may not work for another. A one-size fits all approach to brain enhancement is likely to be impractical and risky.

The ethical implications of brain stimulation are relatively easy to navigate when it’s used for treating disabling medical conditions. But it all gets much more complex when we talk about using brain stimulation in the healthy brain to enhance numeracy, reading, problem solving or learning to kick a football.

Who will have access to this technology? Will it be available in schools, sports training facilities, universities? How will we prevent disadvantaging those whose brains don’t respond? And could this technology simply provide new opportunities for pushy parents to get pushier?

If brain enhancement technology is shown to be effective, these are just a few of the questions we will have to answer.