Electrical stimulation can alter human learning
Scientists at the University of Pennsylvania say that by stimulating certain neurons within the brain, they were able to change the human learning process.
Specifically, the researchers were able to stimulate dopamine-containing neurons in a deep brain structure called the substantia nigra. They say the stimulation possibly altered learning by causing individuals to repeat actions that resulted in reward.
For the study, published in the Journal of Neuroscience, 11 participants underwent deep brain stimulation treatment for Parkinson’s disease. For the portion of the procedure during which they were awake, they played a computer game that asked them to choose between a pair of objects that carried different reward rates. When they clicked on the object, they got a reward, were shown a green screen and the sound of a cash register, similar to in a casino. They were not told which objects were more likely to yield rewards, but figured it out by trial and error.
When the stimulation was provided following a reward, participants were more likely to repeat pushing the button that resulted in reward, even when the rewarded object was no longer associated with that button. This resulted in poorer performance of the game when stimulation was present.
Researchers say that modulating reward-based learning could be useful for treating patients with substance abuse, gambling problems or enhancing rehabilitation in patients with neurological issues.