Prefrontal cortex

The prefrontal cortex (PFC) is involved in complex problem solving and planning future actions and there are good reasons for supposing that these executive tasks require working memory. The connectivity of the prefrontal cortex argues for its role in working memory. Firstly, there are reciprocal connections among the Prefrontal Cortex and other cortical areas so, receives visual, auditory and somatosensory information. Secondly, the Prefrontal Cortex is interconnected with the medial temporal lobe and dorsomedial thalamus that have a well-documented role in learning and memory. Thirdly, the Prefrontal Cortex is a component of the executive thalamocortical-basal ganglia circuit which allows it to modulate by reward and salience.

In spatial delayed response tasks monkeys see a food reward placed in one of various covered locations. After a delay, that can be varied over trials the animals are tested to see if they remember the location of the food.  Monkeys with lesions of the PFC have deficits in these tasks and performance degrades progressively as the delay is lengthened. Recording from the Prefrontal Cortex in alert behaving monkeys reveals cells which fire in predictable ways during delayed-response tasks. For instance several cells fire by the delay time, others fire when the food is placed in the location and when the animal is allowed to select the location. Particular regions of the Prefrontal Cortex seem to be modality-specific evidence for exact subsystems of working memory.

Humans with prefrontal lesions also show deficits on working memory tasks in that they are needed to use recent data to make correct decisions. Like individuals have great difficulty in tracing a path by a drawing of a maze. They will make the similar errors repeatedly and begin right from the starting of the maze after making an error rather than from the position in the maze just before they made the error.