Neuronal responses support a role for orbitofrontal cortex in cognitive set reconfiguration

• Published in: The European journal of neuroscience 2017-04, Vol.45 (7), p.940-951
• Main Authors: Sleezer, Brianna J., LoConte, Giuliana A., Castagno, Meghan D., Hayden, Benjamin Y., Molholm, Sophie
• Format: Article
• Language: English
• Subjects: Animals; Cognition; Cognitive ability; conceptual set‐shifting task; Corpus Striatum - physiology; Decision Making; executive control; Executive function; Macaca mulatta; Male; Neostriatum; Neurons; Neurons - physiology; Prefrontal cortex; Prefrontal Cortex - cytology; Prefrontal Cortex - physiology; rhesus macaque; rule; switching
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.13532

We are often faced with the need to abandon no‐longer beneficial rules and adopt new ones. This process, known as cognitive set reconfiguration, is a hallmark of executive control. Although cognitive functions like reconfiguration are most often associated with dorsal prefrontal structures, recent evidence suggests that the orbitofrontal cortex (OFC) may play an important role as well. We recorded the activity of OFC neurons while rhesus macaques performed an analogue of the Wisconsin Card Sorting Task that involved a trial and error stage. The OFC neurons demonstrated two types of switch‐related activity, an early (switch‐away) signal and a late (switch‐to) signal, when the new task set was established. We also found a pattern of match modulation: a significant change in activity for the stimulus that matched the current perceptual rule (and would therefore be selected). These results extend our understanding of the executive functions of the OFC. They also allow us to directly compare the OFC with the complementary datasets we previously collected in the ventral (VS) and dorsal (DS) striatum. Although both effects are observed in all three areas, the timing of responses aligns the OFC more closely with DS than with VS. We used a rule‐based selection task in which rules changed every 15 trials and monkeys had to determine new rules using trial and error. We found that neurons in the orbitofrontal cortex (OFC) show systematic changes in the firing rate associated with switching between options. These findings highlight a possible role for the OFC in regulating switching between mental rules.