Impulsivity has been associated with several psychiatric disorders including drug addiction and gambling. Impulsive subjects typically have a preference for short-term over long-term rewards and make risky choices. This study used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of self-rated impulsivity and venturesomeness during tasks involving delayed and risky choice. A broader sampling approach was taken by recruiting participants with behaviors that have been linked to impulsivity (gambling N=15, and recreational drug use N=10) and those without these behaviors (N=9). Selection between delayed or probabilistic rewards was associated with activation in fronto-parietal regions in line with previous research. When selecting between delayed rewards, activity within the pregenual anterior cingulate cortex and ventrolateral prefrontal cortex correlated positively with impulsivity scores while activity within the orbitofrontal cortex, subgenual anterior cingulate cortex and caudate correlated positively with venturesomeness scores. Selection between probabilistic rewards revealed no correlation between scores and regional activations. The results from this study provide targets for future research investigating the neural substrates of impulsivity. They also provide targets for the further investigation into the pathophysiology of addiction and impulse-control disorders.
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