Brain and autonomic association accompanying stochastic decision-making.

To examine the functional association between brain and autonomic activities accompanying decision-making, we simultaneously recorded regional cerebral blood flow using (15)O-water positron emission tomography and event-related brain potentials (ERPs) time-locked to feedback of reward and punishment, as well as cardiovascular parameters, during a stochastic decision-making task. We manipulated the uncertainty of outcomes in the task; specifically, we compared a condition with high predictability of reward/punishment (contingent-reward condition) and a condition with low predictability of reward/punishment (random-reward condition). The anterior cingulate cortex (ACC) was commonly activated in both conditions. Compared with the contingent-reward condition, the orbitofrontal and right dorsolateral prefrontal cortices and dorsal striatum were activated in the random-reward condition, where subjects had to continue to seek contingency between stimuli and reward/punishment. Activation of these brain regions correlated with a positive component of ERPs locked to feedback signals (feedback-related positivity), which showed an association with behavioral decision-making in the contingent-reward condition. Furthermore, cardiovascular responses were attenuated in the random-reward condition, where continuous attention and contingency monitoring were needed, and such attenuation of cardiovascular responses was mediated by vagal activity that was governed by the rostral ACC. These findings suggest that the prefrontal-striatal network provides a neural basis for decision-making and modulation over the peripheral autonomic activity accompanying decision-making.