The cerebral hemispheres cooperate to perform complex but not simple tasks

Neuropsychology. 2000 Jan;14(1):41-59. doi: 10.1037//0894-4105.14.1.41.


Three experiments were designed to examine whether task complexity determines the degree to which a division of processing across the hemispheres (i.e., across-hemisphere processing) underlies performance when within- and across-hemisphere processing are equally possible. When task complexity was relatively low, performance in a midline condition that allowed for either within- or across-hemispheric processing resembled within-hemisphere performance (Experiments 1 and 2). However, when task complexity was high, performance in a midline condition (Experiments 1 and 2) and a lateralized condition, which also allowed for either within- or across-hemisphere processing (Experiment 3), resembled across-hemisphere performance. Results complement and extend prior work (e.g., M. T. Banich & A. Belger, 1990) by indicating that the degree to which interhemispheric cooperation underlies performance changes with the complexity of the task being performed. This finding suggests that the hemispheres dynamically couple or uncouple their processing as a function of task complexity.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Brain / physiology*
  • Female
  • Fixation, Ocular / physiology
  • Functional Laterality / physiology*
  • Humans
  • Male
  • Mental Processes / physiology*
  • Reaction Time
  • Surveys and Questionnaires
  • Visual Fields / physiology