Common and distinct electrophysiological correlates of feedback processing during risky and ambiguous decision making.

Risk and ambiguity are two fundamental parameters in decision making, and it remains elusive whether they are dissociable at the neural level. The current EEG study examined the ERP and oscillatory correlates of neural feedback processing under risky and ambiguous decision making. Participants performed a wheel-of-fortune task and received either gain or nongain feedback following risky or ambiguous gambles while their EEG was recorded. Results revealed that the early, obligatory detection of reward information was not dependent on the nature of the previous gamble, which was reflected by the reward positivity. However, risky gambling seemed to elicit an enhanced cognitive control signal as indexed by theta oscillation, whereas ambiguous gambling increased the affective and motivational salience during feedback processing as represented by the P3 and delta oscillation. Together, our findings suggest that feedback processing during risky and ambiguous decision making taps into common and distinct electrophysiological correlates.