The Moderating Effect of Positive Emotionality on EEG Asymmetry Recorded During a Reward Processing Task

There are two components of positive affect in reward processing: anticipatory positive affect occurs before receiving a reward and indicates a desire for a stimulus, and consummatory positive affect happens after receiving a reward and indicates contentment or satisfaction. Individual differences in reward processing have been linked to aspects of personality and asymmetric activity in the frontal brain. Specifically, a pattern of greater relative left asymmetry has repeatedly been associated with approach-related tendencies. However, most of these studies have only recorded EEG at rest and little research has examined asymmetry during a task that induces anticipatory and consummatory positive affect. The current study examined whether individual differences on various measures of positive emotionality predict self-reported mood and EEG responses to a task designed to elicit responses to reward in an unselected sample of undergraduate students. Trait anticipatory positive affect significantly predicted both self-reported anticipation of a win and positive affect in response to a win during the game, over and above other measures of positive affect. Trait consummatory positive affect significantly predicted the reward potentiated asymmetry in response to a win during the slot machine game. These findings clarify patterns of asymmetry during reward processing, as well as provide affective and psychophysiological validation of the Temporal Experience of Pleasure Scale, which is used to measure trait anticipatory and consummatory positive affect.