Impulsivity, a personality characteristic of many psychiatric disorders including substance abuse, involves a preference for immediate rewards over delayed rewards and a disregard of long-term consequences. This application hypothesizes that dysregulation of the ventral tegmental (VTA) dopaminergic reward prediction system leads to a reward hypersensitivity in orbitofrontal cortex (OFC) systems of stimulus evaluation and anterior cingulate cortex (ACC) systems of behavior monitoring among highly impulsive subjects. The proposed experiments investigate reward sensitivity in stimulus evaluation and action monitoring utilizing the temporal resolution of ERPs and spatial resolution of fMRI. The experiments employ normal college students screened and separated into high and low impulsive groups, based on the Barrett Impulsivity Scale, participating in a modified flanker task with rewarding and punishing stimuli testing for reduced ACC activation to errors in impulsive subjects, in a passive S1/S2 paradigm testing for enhanced OFC activation to the prediction of reward in impulsive subjects, and an SI/S2 incentive flanker paradigm examining interactions between OFC and ACC in a reward-motivated decision task.
| Potts, Geoffrey F; Martin, Laura E; Kamp, Siri-Maria et al. (2011) Neural response to action and reward prediction errors: Comparing the error-related negativity to behavioral errors and the feedback-related negativity to reward prediction violations. Psychophysiology 48:218-28 |
| Martin, Laura E; Potts, Geoffrey F (2011) Medial frontal event-related potentials and reward prediction: do responses matter? Brain Cogn 77:128-34 |
| Martin, Laura E; Potts, Geoffrey F; Burton, Philip C et al. (2009) Electrophysiological and hemodynamic responses to reward prediction violation. Neuroreport 20:1140-3 |
| Martin, Laura E; Potts, Geoffrey F (2009) Impulsivity in Decision-Making: An Event-Related Potential Investigation. Pers Individ Dif 46:303 |
