Underground internet circles are aflutter with news that transcranial direct current stimulation (tDCS) can lead to cognitive enhancement and help with a number of mental maladies. But are any of the rumors true, and if so, is it safe?
The tDCS process works by applying a simple electrical current to the scalp. The region of the brain beneath the source of the current responds either with a general increase or decrease in neural activity, depending on the charge of the current. For the past few years researchers have found that tDCS can modulate human cognition and behavior for a brief period of time after the application of the current.
Though the field is still in its infancy, there is certainly reason to be excited about the prospects of tDCS. Early experiments have demonstrated increased learning and cognitive ability when tDCS is applied. While the acute effects of tDCS only last about 75 percent of the time of application (e.g. If you stimulate for 20 minutes, the effects will last only about 15 minutes after the current is removed), any enhanced learning that is achieved during the session could potentially last months, just as learning a task without stimulation would. The difference is that you can potentially acquire that new task (i.e. learn) faster, and better.
For this reason, the task you choose is just as important as the tDCS current. Without a learning task, little is likely to be achieved with electrical stimulation. Similarly, the stimulation has to be in the area of the brain that is performing the task. Stimulation in the wrong part of the brain would have no effect or could potentially impair the task, if you happen to stimulate in an area that negatively regulates the area being used.
Safety is another concern. Most of the studies to date have suggested that tDCS is safe at least in a laboratory setting and for short-term use. The few reported side effects such as itching and headache appear to be mild. However, the safety has not been assessed very rigorously, and the results of long-term and repeated use are unknown. Though the effective voltage used in most of the studies is only around two milliamps, caution must be used to ensure that higher voltages are not accidentally applied.
Needless to say, tDCS should never be tried at home because of these potential risks. Scientists using tDCS in a laboratory setting have the expertise and high-quality equipment to assure the safety of their participants. They also have equipment like EEG and MRI that can help them localize the appropriate brain region for stimulation, as well as the training to understand how and when tDCS could be safe and effective. If you’re curious about tDCS your best bet is to find a local university that studies tDCS and volunteer for an experiment.
When it comes to the science of wellness, distinguishing the facts from the urban legends can be tough. That’s why we’ve enlisted Darya Pino – a scientist, foodie, and self-proclaimed geek girl. Check out the ZocDoc Blog every other Tuesday to see her bust the biggest myths in health.
Image: Brain ventricles 4, a Creative Commons Attribution (2.0) image from Luciana Christiante’s photostream.