Different subregions of monkey lateral prefrontal cortex respond to abstract sequences and their components.

Daily tasks, such as a bus commute, require tracking or monitoring your place (same, same, same, different building) until your stop. Sequence components such as rule, periodicity (timing), and item identity are involved in this process. While prior work located responses to sequence rule changes to area 46 of monkey lateral prefrontal cortex (LPFC) using awake monkey fMRI, less was known about other components. We found that LPFC subregions differentiated between sequence components. Area 46 posterior fundus responded to abstract visual sequence rule changes, but not to changes in image periodicity or identity. The converse was true for the more ventral, adjacent shoulder region. These results suggest that interactions between adjacent LPFC subregions provide key scaffolding for complex daily behaviors.