(53)  TI: HEMISPHERIC-SPECIALIZATION FOR SKILLED PERCEPTUAL ORGANIZATION BY 
          CHESSMASTERS
      AU: CHABRIS_CF, HAMILTON_SE
      NA: HARVARD UNIV,DEPT PSYCHOL,1206 WILLIAM JAMES HALL,33 KIRKLAND 
          ST,CAMBRIDGE,MA,02138
      JN: NEUROPSYCHOLOGIA 1992 Vol.30 No.1 pp.47-57
      AB: The right cerebral hemisphere may be relatively specialized for 
          parsing simple visual stimuli according to default rules, such as 
          the Gestalt laws of perceptual organization, whereas the left 
          cerebral hemisphere may be relatively specialized for overriding 
          such default rules. We extend this model to 'semantically rich 
          domains' by performing a divided-visual-field experiment on 16 
          chessmasters. Such subjects are able to recall and recognize 
          complex chess positions by chunking the basic elements of the 
          stimuli-the chess pieces-into meaningful groupings according to 
          certain rules that are specific to the semantic structure of the 
          chess domain. We show that the right hemisphere is superior to 
          the left at parsing according to the default rules of chess 
          chunking, but that the left hemisphere is superior to the right 
          at grouping pieces together in violation of those rules. These 
          results suggest that the right hemisphere is better able to 
          acquire and apply new sets of default parsing rules for specific 
          contexts. We conclude, consistent with other neuropsychological 
          evidence, that the right hemisphere is critical for chess skill.
      KP: CHESS POSITIONS, MENSTRUAL-CYCLE, MEMORY, INFORMATION, RECALL, 
          TASK