Frontostriatal contributions to reward and value processing. (360G-Wellcome-090201_Z_09_Z)

I have designed experiments to compare automatic vs. controlled allocation of attention under conditions of reward, extending recent studies that show alterations in reward and salience processing in Parkinson s disease and frontal lobe lesions. I will record eye movements and behavioural performance, to measure oculomotor capture by salient stimuli, reward-related speeding and biases, and pupillary responses. I will study the differential effects of reward or penalty, reward expectatio n, motivation, timing, and error awareness. I will study healthy individuals, patients with focal lesions, and Parkinson s patients on and off medication. I will test the following hypotheses: 1. Automatic orienting of gaze is modulated by previous reward at a given location in healthy people 2. Ventromedial (vmPFC) patients have impaired reward sensitivity on oculomotor capture paradigm 3. Pupillary responses to rewards and penalties are different in vmPFC patients, DLPFC patients and controls 4. Patients with Parkinson s disease have altered pupillary responses and reward processing 5. vmPFC patients exhibit exaggerated speeding of eye movements toward valued locations 6. In healthy subjects, dopamine agonists increase reward sensitivity As a result, we will test and develop current neurobiological models of reward-driven behaviour to explain the findings in health and in disease.