Electrodes used for tDCS are attached the scalp of an individual before he performs a multitasking cognitive test. FLICKR, U.S. AIR FORCE, J.M. EDDINS, JR.Zapping the brain with alternating, low-intensity electricity—a technique called transcranial alternating current stimulation (tACS)—does not appear to boost memory-related brainwaves in humans with epilepsy. The finding, published yesterday (October 31) in Nature Communications, raises questions about how electrical stimulation actually affects the natural rhythms of the brain.
Stimulating the brain with electrodes placed on the scalp has gained popularity in the past two decades, with many people buying DIY kits to buzz their brains at home, expecting it to boost brain rhythms that support making and recalling memories. But hard data on how such brain stimulation works have been hard to come by.
“We were very, very surprised to find that tACS . . . did not affect brain waves,” study coauthor Anli Liu, a neurologist at NYU School of Medicine, told The Scientist by email. Liu says the team “tried to increase stimulation intensities, and looked at the data in every manner to look for even a small effect, but could not find anything.”
University of Birmingham neuroscientist Simon Hanslmayr is ...
