Event-Related Potentials Are Associated With Unexpected Gain and Loss: Using a Gambling Paradigm.

Previous neuroimaging studies have described altered activity in brain areas associated with reward processing following reward or punishment. This study examines the extent to which feedback-based experience of gain and loss is associated with electrophysiological correlates. Twenty-nine healthy participants used a gambling task that focused on actual nonpredictable gains and losses. During the task, an electroencephalography recording was performed in order to assess reward processing. Event-related potentials were analyzed when participants were receiving gain/loss feedback. Event-related potentials revealed higher feedback-related negativity for both overall gain and loss compared with a neutral condition in fronto-centro-parietal electrodes. P3 potentials were significantly increased for high gains/losses compared to neutral and small gains/losses. These results indicate that the paradigm is suitable to evoke specific patterns of reward-related electrophysiological responses. The wavelet analysis showed that electroencephalography frequency variations depended on the amount of gains/losses. This gambling paradigm is appropriate to measure aspects of feedback processing and could help analyze disease-specific alterations of the reward system in patients.