General mechanisms of task engagement in the primate frontal cortex
Jan Grohn, Nima Khalighinejad, Caroline Jahn, Alessandro Bongioanni, Urs Schuffelgen, Jerome Sallet, Matthew Rushworth, Nils Kolling, Oxford, United Kingdom
Session:
Posters 1B Poster
Presentation Time:
Thu, 24 Aug, 17:00 - 19:00 United Kingdom Time
Abstract:
Staying engaged with a task is necessary to maintain goal-directed behaviors. Although engagement varies with the specific task at hand it also exhibits continuous, intrinsic fluctuations widely. This intrinsic component of engagement is difficult to isolate behaviorally or neurally in controlled experiments with humans. By contrast, animals spontaneously move between periods of complete task engagement and disengagement, even in experimental settings. We, therefore, looked at behavior in macaques in a series of four tasks while recording fMRI signals. We identified consistent patterns of behavior predictive of impending task disengagement. This made it possible to build models capturing task-independent engagement. We identified common patterns of neural activity linked to impending task disengagement in mid-cingulate gyrus. By contrast, activity centered in perigenual anterior cingulate cortex (pgACC) was associated with maintenance of task performance. Importantly, we were able to carefully control for task-specific factors such as the reward history, choice value, and other motivational effects, such as response vigor, as indexed by response time, when identifying neural activity associated with task engagement. Moreover, we showed pgACC activity had a causal link to task engagement; transcranial ultrasound stimulation of pgACC, but not of control regions, changed task engagement/disengagement patterns.