Rule Encoding in Orbitofrontal Cortex and Striatum Guides Selection

Abstract

Active maintenance of rules, like other executive functions, is often thought to be the domain of a discrete executive system. An alternative view is that rule maintenance is a broadly distributed function relying on widespread cortical and subcortical circuits. Tentative evidence supporting this view comes from research showing some rule selectivity in the orbitofrontal cortex and dorsal striatum. We recorded in these regions and in the ventral striatum, which has not been associated previously with rule representation, as macaques performed a Wisconsin Card Sorting Task. We found robust encoding of rule category (color vs shape) and rule identity (six possible rules) in all three regions. Rule identity modulated responses to potential choice targets, suggesting that rule information guides behavior by highlighting choice targets. The effects that we observed were not explained by differences in behavioral performance across rules and thus cannot be attributed to reward expectation. Our results suggest that rule maintenance and rule-guided selection of options are distributed processes and provide new insight into orbital and striatal contributions to executive control.

Lateral orbitofrontal cortex anticipates choices and integrates prior with current information

“…This result is consistent with recent work where monkey OFC population activity has been postulated to represent an internal deliberation mediating the choice between two options52. It is also in line with a large body of work showing that OFC plays an important role in goal-directed behavior and thus in action initiation and selection (for example, see refs 46, 53, 54, 55, 56, 57). Previous work has also found evidence that a multitude of areas are involved in action initiation and selection, such as parietal and prefrontal areas3419212431.…”

OpenMonkeyStudio: Automated Markerless Pose Estimation in Freely Moving Macaques

“…Subjects were water restricted to 25 mL/kg for initial training, and readily worked to maintain 50 mL/kg throughout experimental testing. Three of the subjects had previously served as subjects on standard neuroeconomic tasks, including a set shifting task (45) and several simple choice tasks (46)(47)(48)(49)(50). Training also included experience with foraging tasks (51,52), including one study using the large cage apparatus (53).…”

A distributed, hierarchical and recurrent framework for reward-based choice

“…For instance, the vmPFC is engaged by several ostensibly value-neutral factors, including autobiographical memory141, spatial navigation142, imagination143 and social cognition144; OFC is engaged by non-reward processes like conflict, working memory, and rule encoding145,146. Likewise, factors that modulate individual neurons in these areas may include ‘valueless’ changes in outcome expectancy147,148, previous outcomes92, intention to switch as well as other strategy variables149, metacognition150, spatial positions of offers and choices45, rules and task set146, and even irrelevant task variables151. It is possible that these apparently value-neutral signals are observed in these tasks because the tasks nevertheless demand the computation of value.…”