Monthly
208 pp. per issue
8 1/2 x 11, illustrated
ISSN
0898-929X
E-ISSN
1530-8898
2014 Impact factor:
4.69

Journal of Cognitive Neuroscience

July 2005, Vol. 17, No. 7, Pages 1115-1129
(doi: 10.1162/0898929054475190)
© 2005 Massachusetts Institute of Technology
A Model of Prefrontal Cortical Mechanisms for Goal-directed Behavior
Article PDF (900.13 KB)
Abstract

Many behavioral tasks require goal-directed actions to obtain delayed reward. The prefrontal cortex appears to mediate many aspects of goal-directed decision making. This article presents a model of prefrontal cortex function emphasizing the influence of goal-related activity on the choice of the next motor output. The model can be interpreted in terms of key elements of Reinforcement Learning Theory. Different neocortical minicolumns represent distinct sensory input states and distinct motor output actions. The dynamics of each minicolumn include separate phases of encoding and retrieval. During encoding, strengthening of excitatory connections forms forward and reverse associations between each state, the following action, and a subsequent state, which may include reward. During retrieval, activity spreads from reward states throughout the network. The interaction of this spreading activity with a specific input state directs selection of the next appropriate action. Simulations demonstrate how these mechanisms can guide performance in a range of goal-directed tasks, and provide a functional framework for some of the neuronal responses previously observed in the medial prefrontal cortex during performance of spatial memory tasks in rats.