Emergence of abstract rules in the primate brain

Goal-directed primate behaviour is guided by abstract rules that group events and experiences into meaningful concepts. Here, Mansouri and colleagues discuss the distributed cortical and subcortical brain regions thought to underlie the formation, maintenance and implementation of abstract rules and propose a unified framework describing the neural architecture of rule-guided primate behaviour. Various aspects of human cognition are shaped and enriched by abstract rules, which help to describe, link and classify discrete events and experiences into meaningful concepts. However, where and how these entities emerge in the primate brain and the neuronal mechanisms underlying them remain the subject of extensive research and debate. Evidence from imaging studies in humans and single-neuron recordings in monkeys suggests a pivotal role for the prefrontal cortex in the representation of abstract rules; however, behavioural studies in lesioned monkeys and data from neuropsychological examinations of patients with prefrontal damage indicate substantial functional dissociations and task dependency in the contribution of prefrontal cortical regions to rule-guided behaviour. This Review describes our current understanding of the dynamic emergence of abstract rules in primate cognition, and of the distributed neural network that supports abstract rule formation, maintenance, revision and task-dependent implementation.