Behavioral flexibility is associated with changes in structure and function distributed across a frontal cortical network in macaques

by J érôme Sallet, MaryAnn P. Noonan, Adam Thomas, Jill X. O’Reilly, Jesper Anderson, Georgios K. Papageorgiou, Franz X. Neubert, Bashir Ahmed, Jackson Smith, Andrew H. Bell, Mark J. Buckley, Léa Roumazeilles, Steven Cuell, Mark E. Walton, Kristine Krug, Rogier B. Mars, Matthew F. S. Rushworth One of the most influential accounts of central orbitofrontal cortex—that it mediates behavioral flexibility—has been challenged by the finding that discrimination reversal in macaques, the classic test of behavioral flexibility, is unaffected when lesions are made by excitotoxin injection rat her than aspiration. This suggests that the critical brain circuit mediating behavioral flexibility in reversal tasks lies beyond the central orbitofrontal cortex. To determine its identity, a group of nine macaques were taught discrimination reversal learning tasks, and its impact on gray matter wa s measured. Magnetic resonance imaging scans were taken before and after learning and compared with scans from two control groups, each comprising 10 animals. One control group learned discrimination tasks that were similar but lacked any reversal component, and the other control group engaged in no learning. Gray matter changes were prominent in posterior orbitofrontal cortex/anterior insula but were also found in three other frontal cortical regions: lateral orbitofrontal cortex (orbital part of area 12 [12o]), cingulate cortex, and lateral prefrontal cortex. In a second analysis, neural ac...
Source: PLoS Biology: Archived Table of Contents - Category: Biology Authors: Source Type: research