A mild electrical stimulation of a specific brain area help people learn and perform a complex motor task better than those in control groups, a new study has found.
Motor skills, which are used for activities from typing and driving to sports, require practice and learning over a prolonged period of time.
The findings could improve prospects of rehabilitation for people with traumatic brain injury, stroke and other conditions.
The study was conducted by researchers of the National Institute of Neurological Disorders and Stroke (NINDS) and Columbia University, New York City and Johns Hopkins University, Baltimore.
During practice, the brain encodes information about how to perform the task, but even during periods of rest, the brain is still at work strengthening the memory of doing the task. This process is known as consolidation.
Participants were presented with a novel and challenging motor task, which involved squeezing a "joy stick" to play a targeting game on a computer monitor, which they practised over five consecutive days.
During practice, one group received 20 minutes of transcranial direct current stimulation (tDCS) and the other group received only a 30 second "sham" stimulation; tDCS involves mild electrical stimulation applied through surface electrodes on the head, and works by modulating the excitability, or activity, of cells in the brain's outermost layers.
In this study, NINDS' Leonardo Cohen and his team directed tDCS to the primary motor cortex, the part of the brain that controls movement.
Over the five-day training period, the skill of the tDCS group improved significantly more that that of the control (sham) group, apparently through an effect on consolidation, said a NINDS release.
During the three month follow-up period, the two groups forgot the skill at about the same rate, but the tDCS group continued to perform better because they had learned the skill better by the end of training.
These finding were published in the early online edition of the Proceedings of the National Academy of Sciences.