A new study shows that electricity can potentially be used to improve the way that human brains work. Researchers Robert Reinhart and John Nguyen of Boston University published some promising findings on electrical stimulation of the brain with regard to memory function. With a test group of 42 older adults and 42 younger folks, the researchers used transcranial alternating current stimulation, or tACS, on the older group to stimulate and tune their brains before and after having them perform short-term memory tests. The results showed that before the electrical stimulation, the older group’s recall rate was around 80 percent, compared with the younger group’s rate of 90 percent. After as little as 10 minutes of stimulation to the brains of the older participants—while their younger counterparts wore caps that provided only a light current, as a placebo—the elder test subjects were able to score 90 percent on the same memory tests.
Neuroscientists have known for many years that human memory is connected to a large network in the brain, which is believed to communicate and organize a person’s ability to recall through what are known as theta waves. It is believed that as people age, those theta waves fall out of sync. It’s the degree to which they fall out of sync—for a variety of reasons—that can result in the symptoms we see with dementia and Alzheimer’s.
The potential uses of this kind of work are very broad. Reinhart told the website Live Science that he believes this research "bodes well for next clinical steps, because we know that there are brain disorders characterized by hypoconnectivity (low connectivity), like autism, schizophrenia and Alzheimer's, but then there are also disorders characterized by too much brain connectivity, like Parkinson's and epilepsy."
The researchers’ use of tACS was specifically designed to help synchronize brain areas that had become uncoupled in older participants. When the same application was used on younger participants, the results were minimal, leading some to say that the treatment was not a memory “enhancer” as much as a fine-tuner. While subjects’ stimulation time varied, Reinhart and Nguyen definitively report that the memory improvement lasted for the entire 50 minutes of memory testing.
Experts are quick to point out that transcranial alternating current simulation is still mostly in its infancy. However, it’s exciting to identify a potential memory loss treatment that requires no invasive actions or surgeries, tends to be moderately inexpensive—especially in the field of brain surgery and experimentation—and doesn’t cause physical discomfort for patients.