Toward a Psychological and Neural Model of Conflict Resolution

Many everyday tasks require overcoming automatic tendencies and impulses to act in accordance with current goals. Imagine getting into the car to drive to a new office. If one is not careful, one might drive the familiar route to the old office instead. Getting to the new workplace requires focusing attention to resolve the conflict between the older automatic responses (e.g., turn right at the first traffic light) and the new, more appropriate goal-directed response (turn left instead). The ability to resolve this conflict has been a focus of many researchers for decades, as it is an ability that is fundamental to human cognition and its dysfunction has been associated with many brain disorders (e.g., ADHD, dementia, depression). To further the understanding of conflict resolution, this project proposes a novel combination of behavioral methods, computational modeling, neuroimaging, and non-invasive brain stimulation. Rather than allowing participants to respond at any point in time, the planned method forces participants to respond at varying times during conflict resolution to interrogate the time course of how conflict is resolved. The project also plans to include undergraduates in research, including those from historically underrepresented groups. The study of conflict resolution has historically relied on analyses of participants’ free response times (RT) in classic cognitive control tasks such as the Stroop, Simon, and Flanker tasks. Although this approach has yielded valuable insights, researchers have recently identified critical limitations with using free RT that have led to an impasse in the understanding of the nature of conflict resolution and its underlying neural mechanisms. The project seeks to address these limitations by combining a forced-response method that generates speed-accuracy tradeoff functions for each participant with a computational model of the response preparation process underlying automatic and goal-directed responding. This project is composed of four research aims: 1) Validate the response preparation model with physiological responses at the muscle using electromyography; 2) Compare the response preparation model against prior sequential sampling models used for conflict tasks; 3) Combine computational modeling with functional neuroimaging (fMRI) and non-invasive brain stimulation (TMS) to assess the causal role of lateral prefrontal cortex in conflict resolution; 4) Assess the generality of the conflict-resolution mechanism across tasks with TMS and the response preparation model. Overall, the results from this project have the potential to deepen our understanding of the neural mechanisms underlying conflict resolution. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.