Widespread changes in firing rate and functional connectivity across the fronto-parietal network during rule guided working memory

Flexible rule-based behavior is an integral component of our daily lives. Rule dependent changes in the activity and functional connectivity of neurons in the frontoparietal network may underlie this flexibility. To test this idea, we simultaneously recorded neural activity from multiple areas in prefrontal and posterior parietal cortices of macaque monkeys while they performed a delayed match-to-sample task involving a non-instructed switch between location and identity matching rules. Our analysis revealed rule-dependent differences in firing rates during all phases of the task and marked task-dependent increases in spike count correlations with only weak differences between rules. These effects were widespread with a high incidence occurring within and between the dorsolateral prefrontal cortex, the lateral intraparietal area and area PG. We conclude that rule based visual working memory is associated with widespread modifications in excitability and functional connectivity across the frontoparietal network.