The proposed research training plan will integrate behavioral and neuroimaging techniques to elucidate the mechanisms underlying inhibition induced devaluation (IID). IID involves withholding a response in the context of specific stimuli, which reduces the value of the stimuli and even results in a subject being less willing to choose or use those stimuli in the future. IID holds great promise for improving public health, because a variety of public health problems, including unhealthy eating, drug abuse, alcohol abuse, and problem gambling, can be distilled to the inability to control the use of something of inherent or perceived value. The promise of IID is that by devaluing a stimulus by associating it with inhibition, an individual will be able to more effectively control their urge to use the valuable bt dangerous substance, facilitating better, healthier choices. Existing work has shown that IID can devalue various stimuli and can result in a subject choosing the devalued stimuli less often, but the current state of IID literature is a smattering of empirical findings with little explanations f the mechanisms that drive IID. This research training plan aims to take the essential step in uncovering the necessary and sufficient inhibitory mechanisms that drive IID as well as the most efficacious procedure to drive IID.
Aim 1 uses behavioral testing to explore inhibition-related mechanisms, revealing which aspects of inhibition-related processing drive devaluation. IID may seem to rest on sound theoretical ground, but the concept of inhibition is heterogeneous and is often treated as a family of related but distinguishable inhibition- related processes.
Aim 1 carves inhibition-related processes at four fundamental joints, determining whether IID is driven by restraint versus cancellation, consistent versus varied mapping between stimuli and inhibition, proactive versus reactive inhibition, and attempted versus completed inhibition. The most efficacious procedure identified in Aim 1 for IID will be used in Aim 2.
Aim 2 will be the firt study to leverage the existing inhibition and value-based decision making literatures to elucidate the neural networks underlying IID. Inhibition recruits a fronto-basal ganglia network and value-based decision making recruits frontal nodes including the ventromedial prefrontal cortex and orbitofrontal cortex.
Aim 2 proposes to answer when and how inhibition drives devaluation by examining which nodes and networks in these well-described networks can be decoded to predict the degree of behavioral devaluation. Under the supervision of Dr. Russell Poldrack, a foremost neuroimaging expert, the applicant will train on new neuroimaging methods necessary for Aim 2. The promise of this research training plan for advancing public health is in providing a mechanistic explanation for IID. This work aims to establish the theoretical foundation necessary to predict how to best use IID as an intervention for reducing problem behaviors that diminish public health.
Recent empirical work shows that associating specific stimuli (e.g., alcoholic beverages) with inhibition reduces the subjective value of those stimuli, which makes it easier for subjects to choose other, potentially healthier choices (e.g., water). So calle inhibition induced devaluation (IID) holds great promise for improving public health because a variety of public health problems including unhealthy eating, drug abuse, alcohol abuse, and problem gambling, can be distilled to the inability to control the use of something of inherent or perceived value. This project involves new training in neuroimaging to allow convergent behavioral and neuroimaging methods to elucidate the mechanisms underlying IID and the most efficacious procedure to yield IID.
