Grant: Discovery Grants Program - Individual

Effective interaction with the world around us depends on the ability to modify our behaviour in response to environmental cues. These cues provide information on appropriate actions, not only which responses are correct but also when they should be initiated. Standing at an intersection in any large city makes this point obvious: failure to wait for a green light can have disastrous consequences. During the last granting period, my research team focused on these impulsive actions, behaviours we describe as 'right move, wrong time'. Our work in animal models revealed novel pharmacological, cellular and molecular mechanisms of impulsive action. We now propose to move the work in a new direction by investigating how impulsivity and reward processes interact, and how this interaction is disrupted in pathological conditions such as drug abuse. Specific projects will be organized around five central themes. The first will use electrophysiological techniques to examine the role of specific cortical regions in learning to inhibit a motor response. The second will investigate the genetic basis of impulsive action using state-of-the-art molecular biology tools. The third set of experiments will attempt to uncover the cognitive processes that contribute to impulsive responding and the neural systems that mediate these effects. The fourth set of studies will examine how individual differences in reward processing alter impulsive action. Finally, we will investigate the relationship between impulsive action and compulsive responding for natural rewards, using a rat model of sucrose bingeing. In the long-term, I propose to extend this work from proximate (causal) to ultimate (functional) explanations of behaviour by examining the evolutionary significance of impulsive action. This systematic investigation of the mechanisms underlying impulsivity-reward interactions will provide a comprehensive understanding of how individuals navigate in their environment, producing both adaptive and maladaptive responses to rewarding stimuli.