Lateralization in a bihemispheric neural model of letter identification

The causes of cerebral lateralization of cognitive and other functions are currently not well understood. A bihemispheric neural network model for a simple visual identification task was developed to study this issue, with two hemispheric regions interacting via a simulated corpus callosum. Lateralization occurred when underlying hemispheric asymmetries were present, including asymmetric size, excitability, or synaptic plasticity, supporting the belief that biological lateralization may be caused by multiple factors independently. Lateralization was more intense with strong inhibitory callosal connections, supporting the hypothesis that the corpus callosum plays a functionally inhibitory role. (C) 1999 Elsevier Science B.V. All rights reserved.