Boosting the brain can lead to an overload

April 27, 2016 - 06:00
Article from University of Oslo

Electrical stimulation of the brain's cells whilst solving challenging tasks can lead to mental overload.

(Illustrative photo: Colourbox.)

Three master's students at the University of Oslo's Psychology Institute wanted to see whether sending a very weak electrical current through the skull to the outer layers of the brain, so-called transcranial direct current stimulation (tDCS), can actually make us smarter.

The young scientists’ suprising result has recently been published in the international journal Neuropsychologia.

Electrified brains

tDCS has piqued the interests of neuroscientists everywhere. The reason is that many claim that the treatment can, amongst other things, help improve memory, increase self-control and make us more creative. tDCS is already used in the rehabilitation of a range of psychiatric and neurological conditions, such as depression, stroke, Alzheimer’s disease, fibromyalgia and tinnitus.

The technology behind the treatment is quite simple. You attach a headset with electrodes that emit small doses of electricity. This stimulates the brain-cells and increases their activity. 

And what's more, is that anyone can get their hans on this kind of technology - and it's fairly easy to use. 

The Norwegian students were eager to see if this treatment can enhance your ability to solve difficult tasks.

The brain crashed

The researchers designed an experiment where they gave participants various tasks. They divided the tasks into three levels – simple, medium and difficult. For comparison, the participants were asked to solve several tasks with various levels of difficulty. 

However, without notifying the participants, the researchers turned the tDCS equiptment off.

To the students suprise, they found no effect of stimulation when participants performed the simple and medium tasks, yet they found a large negative effect on the most difficult tasks.

Nina Chung Mathiesen and James Roe are two of the researchers behind this discovery. (Photo: Svein Harald Milde/UiO.)

"We saw that participants experienced severe problems concentrating when the task was most difficult and the brain was being stimulated. This was in comparison to perfomance on the same difficulty level when participants only thought they were being stimulated. It was as though tDCS had completely overloaded a brain region crucial to performing the task, as though it crashed it," explains James Roe, one of the lead reseachers.

Might still have a positive effect

"Those that claim that tDCS can increase attention and cognitve ability have maybe not tested the device whilst performing already extremely difficult tasks," adds co-author Mathias Nesheim.

The young researchers acknowledge that tDCS can indeed have a positive impact, and instead point out that their study has shed light on the effects of tDCS when we solve tasks of varying difficulty.

"The tasks the brain is performing whilst receiving electrical stimulation, as well as the brain region being stimulated, are factors that absolutely help determine the effects of stimulation," emphasizes Nesheim.

Warns against daily use

tDCS is often sold as a universal brain performance-enhancing device, as well as a promising self-treatment method for both psychological and physical afflictions. As a result, an entire subculture of self-stimulators has emerged in recent years.

The American Air Force has previously tested the implementation of tDCS in the training programmes of drone pilots, and claims to have cut training time in half. The US Army has also tested its use when training military personell. Gamers place tDCS on their heads and play for hours, and students do the same while they read for exams.

Nina Chung Mathiesen, the third student working on the project, admits to having used tDCS, but warns against using it on a daily basis. 

"It is pain free and so far there is little evidence for any unpleasant or lasting side-effects, but I would still be careful when it comes to sending daily doses of electricity through one’s brain."

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