Fri, 04 Jul 2008 23:51:18 BST CiteULike: Group: Glimcher_Lab - with tag pfc http://www.citeulike.org/group/70/tag/pfc CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/group/70/article/525382 <i>J Neurosci, Vol. 18, No. 1. (1 January 1998), pp. 428-437.</i><br /><br />We tested the hypothesis that cognitive functions related to working memory (assessed with delay tasks) are distinct from those related to decision making (assessed with a gambling task), and that working memory and decision making depend in part on separate anatomical substrates. Normal controls (n = 21), subjects with lesions in the ventromedial (VM) (n = 9) or dorsolateral/high mesial (DL/M) prefrontal cortices (n = 10), performed on (1) modified delay tasks that assess working memory and (2) a gambling task designed to measure decision making. VM subjects with more anterior lesions (n = 4) performed defectively on the gambling but not the delay task. VM subjects with more posterior lesions (n = 5) were impaired on both tasks. Right DL/M subjects were impaired on the delay task but not the gambling task. Left DL/M subjects were not impaired on either task. The findings reveal a cognitive and anatomic double dissociation between deficits in decision making (anterior VM) and working memory (right DL/M). This presents the first direct evidence of such effects in humans using the lesion method and underscores the special importance of the VM prefrontal region in decision making, independent of a direct role in working memory. Dissociation Of working memory from decision making within the human prefrontal cortex. A Bechara H Damasio D Tranel SW Anderson J Neurosci, Vol. 18, No. 1. (1 January 1998), pp. 428-437. 2006-03-01T14:48:36-00:00 1998 J Neurosci 0270-6474 18 1 428 437 decisionmaking pfc workingmemory http://www.citeulike.org/group/70/article/472847 <i>Nat Rev Neurosci, Vol. 1, No. 1. (October 2000), pp. 59-65.</i><br /><br />One of the enduring mysteries of brain function concerns the process of cognitive control. How does complex and seemingly willful behaviour emerge from interactions between millions of neurons? This has long been suspected to depend on the prefrontal cortex--the neocortex at the anterior end of the brain--but now we are beginning to uncover its neural basis. Nearly all intended behaviour is learned and so depends on a cognitive system that can acquire and implement the 'rules of the game' needed to achieve a given goal in a given situation. Studies indicate that the prefrontal cortex is central in this process. It provides an infrastructure for synthesizing a diverse range of information that lays the foundation for the complex forms of behaviour observed in primates. The prefrontal cortex and cognitive control. EK Miller Nat Rev Neurosci, Vol. 1, No. 1. (October 2000), pp. 59-65. 2006-01-20T19:33:26-00:00 2000 Nat Rev Neurosci 1471-003X 1 1 59 65 cognitivecontrol macaques pfc review http://www.citeulike.org/group/70/article/2188656 <i>Science, Vol. 301, No. 5637. (29 August 2003), pp. 1246-1249.</i><br /><br />Complex biological systems such as human language and the genetic code are characterized by explicit markers at the beginning and end of functional sequences. We report here that macaque prefrontal cortical neurons exhibit phasic peaks of spike activity that occur at the beginning and endpoint of sequential oculomotor saccade performance and have the properties of dynamic start- and end-state encoders accompanying responses to sequential actions. Sequence bounding may thus reflect a general mechanism for encoding biological information. Representation of action sequence boundaries by macaque prefrontal cortical neurons. N Fujii AM Graybiel doi:10.1126/science.1086872 Science, Vol. 301, No. 5637. (29 August 2003), pp. 1246-1249. 2008-01-02T16:32:52-00:00 2003 Science 1095-9203 301 5637 1246 1249 action macaques pfc representation sequencce