Zaps to the head can enhance people’s memory by coaxing brain regions to work together. The brain stimulation method called transcranial magnetic stimulation, or TMS, helped healthy people recall words paired with faces, neuroscientist Joel Voss of Northwestern University’s medical school in Chicago and colleagues report in the Aug. 29 Science.
In TMS, an electromagnetic coil placed on the head produces small electrical currents that stimulate nerve cells close to the brain’s surface. A logical location for stimulation would be the hippocampus, a brain structure important for memory. But the hippocampus is buried too deeply in the brain to be reached with TMS. The researchers instead turned to a spot near the top left surface of the brain’s wrinkly outer layer that’s known to work closely with the hippocampus.
In the study, 16 healthy subjects underwent functional MRI scans to pinpoint the exact coordinates of this spot. Participants received stimulation at the brain location for 20 minutes for five days. About 24 hours after their last stimulation, participants saw pictures of faces paired with spoken words. About a minute after first learning the pairs, participants better remembered which word went with each face than when they hadn’t been stimulated, the team found.
The technique might be useful for people who suffer from disorders that come with memory loss, the authors propose.