Neuroscientists from the University of Pennsylvania have published a study in Current Biology on using electrical brain stimulation as a treatment to improve memory in the human brain.

Led by Michael Kahana, professor of psychology and principal investigator of the Defense Advanced Research Projects Agency's Restoring Active Memory program, and Youssef Ezzyat, a senior data scientist in Kahana's lab, the study tested the effectiveness of electrical stimulation in improving brain function and memory in patients receiving care for epilepsy. The study aimed at restoring one's capacity for active memory.

Researchers first had to understand the brain signaling patterns in regard to memory to examine how electrical stimulation affects poor and normal memory function.

"By applying machine-learning methods to electrical signals measured at widespread locations throughout the human brain, we are able to identify neural activity that indicates when a given patient will have lapses of memory encoding," said Ezzyat, the lead author.

The study enrolled neurosurgical patients receiving treatment for epilepsy from a wide range of hospitals and asked them to recall lists of common words while receiving brain stimulation. Researchers recorded electrical activity through implanted electrodes in the patients' brains to identify biomarkers and measure changes in memory function.

"We found that, when electrical stimulation arrives during periods of effective memory, memory worsens," said Kahana. "But when the electrical stimulation arrives at times of poor function, memory is significantly improved."

Improvements in brain stimulation technology may have the potential to improve quality of life in those with Alzheimer’s and traumatic brain injuries.