Different time courses of learning-related activity in the prefrontal cortex and striatum

The ability to follow arbitrary associations, such as “stop at red”, is integral to everyday behaviour and the primate brain is quick to learn them. Both the prefrontal complex and the striatum have been implicated in this process, but their respective roles are largely unknown. An experiment in which brain activity in these two areas was recorded while monkeys learned new associations shows that the learning-related changes occur much more quickly in the striatum, but that changes in the prefrontal cortex were more closely related to improved performance of the new task. It is possible that the striatum learns first, then ‘trains’ the prefrontal cortex.