Study participants were asked to perform a simple behavioral task that required the braking/slowing of action – inhibition – in the brain. In each participant, the researchers first identified the specific location for this brake in the prefrontal region of the brain. Next, they increased activity in this brain region using stimulation with brief and imperceptible electrical charges. This led to increased braking – a form of enhanced self-control.
This proof-of-principle study appears in the Dec. 11 issue of The Journal of Neuroscienceand its methods may one day be useful for treating attention deficit hyperactivity disorder (ADHD), Tourette's syndrome and other severe disorders of self-control.
"There is a circuit in the brain for inhibiting or braking responses," said Nitin Tandon, M.D., the study's senior author and associate professor in The Vivian L. Smith Department of Neurosurgery at the UTHealth Medical School. "We believe we are the first to show that we can enhance this braking system with brain stimulation."
A computer stimulated the prefrontal cortex exactly when braking was needed. This was done using electrodes implanted directly on the brain surface.
When the test was repeated with stimulation of a brain region outside the prefrontal cortex, there was no effect on behavior, showing the effect to be specific to the prefrontal braking system.
This was a double-blind study, meaning that participants and scientists did not know when or where the charges were being administered.