Study finds electrical brain stimulation impairs memory

tDCS developer edition--Courtesy of

A study by two psychologists at Germany's Max Planck Institute on Human Development poured cold water on the use of brain electrical stimulation techniques, lending support to those who dismiss the methods of supposedly improving memory and mood as pseudoscience.

The researchers tested a CE-marked brain stimulation device that delivers transcranial direct current stimulation via electrodes, which were placed on the scalp of 24 subjects, who received both active and sham stimulation.

It turns out that tDCS impairs memory, according to the results of patients' performance on working memory tasks performed after each (real or fake) stimulation session.

"Even if preliminary, these results show the fundamental critical and active role of the scientific community in evaluating the sometimes far-reaching, sweeping claims from the brain training industry with regard to the impact of their products on cognitive performance," said study author Lorenza Colzato in a news release.

The device used was "the world's most advanced electrical brain stimulator," and increases brain plasticity, if the website of manufacturer is to be believed.

The $299 stimulator and various accessories can be purchased online.

Meanwhile, startup Thync is developing a smartphone-connected product that boosts users' mood using tDCS to produce a short-term energizing effect equivalent to drinking a can of Red Bull, and a calming effect equivalent to drinking a couple beers or taking Benadryl, cofounder Jamie Tyler previously told the MIT Technology Review. To achieve the "Red Bull" effect, the device sends barely noticeable electrical currents to the skin just behind the ear, and for the relaxing sensation, the product sends currents to the temple and back of the neck.

Don't be too quick to dismiss electrical brain stimulation as pseudoscience. A 2013 study in published in the Journal of the American Medical Association found that direct currents applied to the cranium can boost the effectiveness of antidepressants.

Whether due to differing study results, or the rise of do-it-yourselfers who perform brain simulation using simple homemade devices, brain stimulation is a quandary for the medical and regulatory communities.

- read the news release
- read the study abstract and/or download the paper