Electrical Pulses to Scalp May Boost Memory: Study
But years of research remain before this therapy could treat brain disorders, experts say
By Amy Norton
THURSDAY, Aug. 28, 2014 (HealthDay News) -- Scientists have found that sending electrical currents through the scalp to a specific network of brain structures can enhance people's memories, for up to a day.
In a small study of healthy young adults, researchers used transcranial magnetic stimulation (TMS) to fire up certain networks involved in memory. That, in turn, boosted participants' performance on memory tests -- an improvement apparent 24 hours after the brain stimulation.
During TMS, an electromagnetic coil is placed on the scalp to create electrical currents that stimulate brain cells. In the United States, the procedure is approved for hard-to-treat cases of depression that don't improve with standard treatments.
Experts stressed, however, that no one should seek out TMS to get better grades or to treat memory loss.
"This study is really a proof-of-concept," said senior researcher Joel Voss, an assistant professor at Northwestern University Feinberg School of Medicine in Chicago.
"It will take a lot more development before this could be used therapeutically," Voss said.
The study, which appears in the Aug. 29 issue of Science, included 16 healthy adults aged 21 to 40. All underwent MRI scans to pinpoint a network of brain cells right below the skull that are well connected with the hippocampus -- a structure deep in the brain that is key in memory.
The researchers hoped that by stimulating those superficial brain structures with TMS, they could rev up the hippocampus and improve people's memories.
To test that idea, Voss's team had the study participants take a test of associative memory, where they had to learn and remember a set of arbitrary associations between faces and words. The men and women then received 20 minutes of TMS every day for five consecutive days.
After three days, the researchers found, test performance started to improve. The gains were still there when the participants took the test 24 hours after the final TMS session.
It wasn't just a matter of the test-takers getting better over time, according to the researchers. On a separate week, study participants all had "placebo" TMS -- with no real brain stimulation -- and their test performance did not improve.