Modulation of ocular motor decisions by reward: an investigation of neural processes using converging methods

The prospect of reward or punishment is known to affect how people make decisions. However, it is not clear which neural systems are involved in this process. This is an important topic in healthcare, because impaired processing of reward information is known to affect the decision-making abilities of many people, including those with damage to the frontal lobe of their brains, Parkinson’s disease, depression/anxiety, obsessive compulsive disorder, and even normal aging. A striking example of this situation occurs among some people with Parkinson’s disease, who can develop pathological gambling behaviours as a result of taking dopaminergic drugs. An effective way to study these neural systems is to track eye movement decisions – in other words where people focus their visual attention. Typically, people are faster to make an eye movement and are more accurate in their eye positions when the movement is rewarded by monetary gain. However, these effects are degraded in certain psychiatric conditions, such as anxiety and depression. Dr. Linda Lanyon is investigating the brain circuits that mediate these reward-related decisions in healthy humans. Her findings will enable her to develop a computer model of the brain circuitry and function that is able to simulate the behaviours observed in humans. In addition to demonstrating how these systems operate in healthy humans, the computer model can also be selectively damaged in order to simulate pathological behaviours observed in patients. By using healthy subjects to create a computer model for decision-making, Linda hopes to improve the understanding of the pathology of neurologically-impaired circuits.