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Abstract:
Abstract: The caudate nucleus has been implicated in
reward-related processing. In a prior study, we developed a
card-game task where participants received monetary feedback after
guessing if the value of a card was higher or lower than the number
5. Participants were financially rewarded for correct guesses and
punished for incorrect responses. We found that the caudate nucleus
showed a pattern of sustained activation after presentation of a
monetary reward, in contrast to a decay in hemodynamic response
after a punishment (Delgado et al., 1999). In this study, we tested
whether the activity of the caudate nucleus could be modulated by
parametric variations in the amount of financial reward or
punishment participants received. We used an event-related fMRI
design in which participants received one of four possible
feedbacks on each trial. They received either high ($4.00) or low
($0.40) monetary reward for a correct guess, or a high ($2.00) or
low ($0.20) monetary punishment for a wrong guess. Regardless of
the size of the reward, activation in the caudate was more
sustained after a reward feedback than when a high or low
punishment was the outcome of a trial.
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