RT Journal Article
SR Electronic
T1 Dopamine, Corticostriatal Connectivity, and Intertemporal Choice
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 9402
OP 9409
DO 10.1523/JNEUROSCI.1180-12.2012
VO 32
IS 27
A1 Andrew S. Kayser
A1 Daicia C. Allen
A1 Ana Navarro-Cebrian
A1 Jennifer M. Mitchell
A1 Howard L. Fields
YR 2012
UL http://www.jneurosci.org/content/32/27/9402.abstract
AB Value-based decisions optimize behavioral outcomes. Because delayed rewards are discounted, an increased tendency to choose smaller, immediate rewards can lead to suboptimal choice. Steep discounting of delayed rewards (impulsivity) characterizes subjects with frontal lobe damage and behavioral disorders including substance abuse. Correspondingly, animal studies and indirect evidence in humans suggest that lower dopamine in the frontal cortex contributes to steeper discounting by impairing corticostriatal function. To test this hypothesis directly, we performed a randomized, double-blind, counterbalanced, placebo-controlled study in which we administered the brain penetrant catechol-O-methyltransferase inhibitor tolcapone or placebo to healthy subjects performing a delay discounting task. Tolcapone significantly increased choice of delayed monetary rewards, and this tolcapone-induced increase covaried with increased BOLD activity in the left ventral putamen and anterior insula. Tolcapone also changed corticostriatal connectivity: specifically, by inducing a decrease in the coherence between ventral putamen and pregenual cingulate cortex. These results indicate that raising cortical dopamine levels attenuates impulsive choice by changing corticostriatal function.