2011 |
Savine, Adam C. |
F31Activity Code Description: To provide predoctoral individuals with supervised research training in specified health and health-related areas leading toward the research degree (e.g., Ph.D.). |
Neural Dissociation of the Contextual and Local Effects of Motivation
DESCRIPTION (provided by applicant): This proposal explores the neural and psychological mechanisms of how motivation provides benefits for cognitive control. Control processes are thought to be the fundamentally important as they allow for successful goal directed behavior via processes such as inhibition, task-switching, and maintaining intentions. Motivation is thought to directly modify the ability of individuals to use effective cognitive control by changing the importance of goals to be pursued. Crucially, a wide range of neuropsychiatric disorders such as schizophrenia, depression, substance abuse, and ADHD are characterized by both breakdowns in cognitive control and at times marked motivational deficits (e.g. anhedonia and avolition in schizophrenia and depression). A growing body of work has provided evidence that the neural systems involved with cognitive control include dorsal frontoparietal circuits, along with the midbrain dopamine system, and that motivation may modulate cognitive control via the midbrain dopamine system. Yet, the precise brain mechanisms underlying interactions between cognitive control and motivational systems, and subsequent impacts on goal directed behavior, remain ill-defined. Our previous work has demonstrated that greater understanding of how motivation impacts cognitive control may come by examining the mechanisms that underlie the two dissociable behavioral effects motivation has on performance: a transient, trial-by-trial preparatory effect, and a sustained, global effect. The current proposal tests the hypothesis that important qualitative distinctions exist between the transient and sustained effects of motivation in how they impact cognitive control, and that these differences will be reflected by dissociable patterns of brain activity, both localized and across associated networks of brain regions. These hypotheses will be tested in a two-session neuroimaging study (using state-of-the-art functional magnetic resonance imaging methods and analytical techniques) that systematically examines these distinctions from within a task-switching experimental paradigm (which involves the explicit switching of goals) in healthy, young adults. The results will also be interpreted in regards to individual differences in the baseline asscoiations between brain regions at rest to probe how these baseline associations between brain regions mediate the effects that motivation has on cognitive control. Success in this work would represent a significant theoretical advance, by clarifying the neural mechanisms and behavioral consequences of how motivation enhances control over cognition. Success in this work would also provide a foundation to further study how motivational deficits may lead to the cognitive control deficits observed in neuropsychiatric populations. PUBLIC HEALTH RELEVANCE: This project has high relevance for public health in terms of the potential to provide critical information regarding the neural and psychological bases of how motivation 1) operates via dissociable sustained and transient effects in the brain, in both a localized and network wide manner and 2) how those effects lead to transient enhancements and sustained benefits in cognitive control. This research although done with healthy individuals, has great significance for clinical populations (e.g. schizophrenia, depression, ADHD, substance abuse) as the obtained knowledge regarding how motivational mechanisms influence goal-directed behavior could be used to better understand the deficits in these disorders, and drive the development of more effective interventions in these populations.
|
1 |