Risk-Sensitive Decision-Making in Patients with Posterior Parietal and Ventromedial Prefrontal Cortex Injury

STUDER, B; MANES, F; HUMPHREYS, G; ROBBINS, TW; CLARK, L

CEREBRAL CORTEX

OXFORD UNIV PRESS INC

Lugar: Oxford; Año: 2013

1047-3211

Successful choice under risk requires the integration of informationabout outcome probabilities and values and implicates a brainnetwork including the ventromedial prefrontal cortex (vmPFC) andposterior parietal cortex (pPAR). Damage to the vmPFC is linked topoor decision-making and increased risk-taking. Electrophysiologicaland neuroimaging data implicate the pPAR in the processing of rewardprobability during choice, but the causal contribution of this area hasnot been established. We compared patients with lesions to the pPAR(n=13), vmPFC (n=13), and healthy volunteers (n=22) on the RouletteBetting Task, a measure of risk-sensitive decision-making. Bothlesion groups were impaired in adjusting their bets to the probability ofwinning. This impairment was correlated with the extent of pPAR, butnot vmPFC, damage. In addition, the vmPFC group chose higher betsthan healthy controls overall, an effect that correlated with lesionvolume in the medial orbitofrontal cortex. Both lesion groups earnedfewer points than healthy controls. The groups did not differ on 2tasks assessing probabilistic reasoning outside of a risk-rewardcontext. Our results demonstrate the causal involvement of both thepPAR and vmPFC in risk-sensitive choice and indicate distinguishableroles of these areas in probability processing and risk appetite.