Penn and Harvard researchers lead
charge in warning ‘Do-it-yourself’ users of transcranial direct current
stimulation seeking enhanced brain function of potential unintended results. The
growing trend of do-it-yourself transcranial direct current stimulation (tDCS)
poses hidden risks to healthy members of the public who seek to use the
technique for cognitive enhancement. Researchers from the Perelman School of
Medicine at the University of Pennsylvania and Beth Israel Deaconess Medical
Center, a Harvard Medical School teaching hospital, along with several members
of the (cognitive) neuroscience research community warn about such risks
involved in home use of tDCS, the application of electrical current to the
brain. Their Open Letter will appear in the July 7th issue of Annals of
Neurology. tDCS devices are made up of a band that wraps around one’s head with
electrodes placed at specific scalp locations to target specific brain regions
which transmit varying levels of electrical current to the brain to achieve the
desired result, such as an enhanced state of relaxation, energy, focus,
creativity, or a variety of other goals. Because tDCS devices are easily made
from simple tools, the practice of self-administered brain stimulation by the
lay community has grown in recent years.
Cognitive neuroscience research
suggests that tDCS can enhance cognition, and relieve symptoms of anxiety,
depression, and other conditions. Published results of these studies might lead
DIY tDCS users to believe that they can achieve the same results if they mimic
the way stimulation is delivered in research studies. However, there are many
reasons why this simply isn’t true. It is important for people to understand
why outcomes of tDCS can be unpredictable, because we know that in some cases,
the benefits that are seen after tDCS in certain mental abilities may come at
the expense of others. First, it is not yet known whether stimulation extends
beyond the specific brain regions targeted. These indirect effects may alter
unintended brain functions. We don’t know how the stimulation of one brain
region affects the surrounding, unstimulated regions. Stimulating one region
could improve one’s ability to perform one task but hurt the ability to perform
another. In addition, what a person is doing during tDCS – reading a book,
watching TV, sleeping – can change its effects. Which activity is best to
achieve a certain change in brain function is not yet known. We know that
stimulation from a few sessions can be quite lasting, but we do not yet know
the possible risks of a larger cumulative dose over several years or a lifetime.
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