The role of computational modeling in understanding hemispheric interactions and specialization

We describe results from three models of paired left and right cerebral regions communicating via a simulated corpus callosum. Conditions are identified under which lateralization emerges during learning, and under which an intact hemispheric region contributes to recovery when the contralateral one is damaged. It proved easy to demonstrate hemispheric specialization in the context of a variety of underlying cortical asymmetries, consistent with past arguments that lateralization of cognitive functions is a multi-factorial process. However, no single assumption about transcallosal influences could account for all existing experimental data. Possible solutions to this ‘callosal dilemma’ are suggested.