Shaun R. Patel
Posters-Accepted Abstracts: J Neurol Neurophysiol
We report single-unit responses recorded from the human subthalamic nucleus (STN) in patients undergoing deep brain
stimulation while engaged in a financial decision-making task. The task is modeled as a simplified version of the classic
card game “war”. The subject is dealt a card and asked to make a high or low wager ($5 or $20). Immediately following their
choice they are shown their opponent’s card––the player with the highest card wins. We recorded 20 individual neurons from 5
patients. We found that during the go-cue period, neuronal activity in the STN predicted whether the subject would ultimately
bet high or low on trials where the probability of a positive or negative outcome were equal (6-card trials, two-tailed t-test, p =
0.03). To explore this further, we used intermittent electrical stimulation to assess changes in financial decision-making. Using
modified stimulator we applied one of three stimulation conditions during 6-card trials: no stimulation, 1 sec of stimulation
at the fixation, or 1 sec of stimulation at the go-cue epoch. We found that intermittent stimulation at the go-cue epoch––the
same period STN neurons encode the upcoming decision––biases subject to make a low wager (binomial proportion, 95% c.i.).
Fixation and no stimulation categories had no effect on decision-making. In this study, we demonstrated that neuronal activity
in the dorsal STN predicts financial decisions. We then showed that we could apply intermittent electrical stimulation through
the implanted electrode to bias the decision signal and ultimately alter the subject’s behavior.
