[Prefrontal cortex in memory and attention processes].

INTRODUCTION: The role of the prefrontal cortex still remains poorly understood. Only after 1970, the functions of the frontal lobes have been conceptualized from different points of view (behaviorism, cognitivism). DEVELOPMENT: Recently,different parallel circuits connecting discrete cortical and subcortical regions of the frontal lobes have been described. Three of these circuits are the most relevant to understanding of behavior: the dorsolateral prefrontal circuit, that mediates executive behavior; the orbitofrontal prefrontal circuit, mediating social behavior, and the medial frontal circuit, involved in motivation. Damage to the frontal cortex impairs planning, problem solving, reasoning, concept formation, temporal ordering of stimuli, estimation, attention, memory search, maintaining information in working memory, associative learning,certain forms of skilled motor activities, image generation and manipulation of the spatial properties of a stimulus, metacognitive thinking, and social cognition. Several theories have been proposed to explain the functions of the prefrontal cortex. Currently,the most influential cognitive models are: the Norman and Shallice supervisory attentional system, involved in non-routine selection; the Baddeley working memory model with the central executive as a supervisory controlling system, in which impairment leads to a 'dysexecutive syndrome'; and the Grafman's model of managerial knowledge units, stored as macrostructured information in the frontal cortex.
CONCLUSION: The prefrontal cortex is essential for attentional control, manipulation of stored knowledge and modulation of complex actions, cognition, emotion and behavior.