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.
Bibliographical noteFunding Information:
This work was supported by the National Institutes of Health (Grant R01 DA038106 to B.Y.H. and Training Fellowship T32-EY007125 to B.J.S.). We thank Marc Mancarella for general laboratory assistance and Giuliana Loconte for assistance with data collection.
© 2016 the authors.
- Decision making
- Executive control
- Orbitofrontal cortex
- Single unit