Effects of callosal lesions in a computational model of single-word reading.

Publisher Summary This chapter describes the effects of corpus callosum lesions on hemispheric functions. The chapter focuses on the previous studies of the model by examining the effects of simulated callosal lesions on the model's performance and lateralization under a wide variety of assumptions about hemispheric asymmetries, divergence of callosal connections, and strength of callosal influences. Of particular interest is the extent to which post-lesion recovery arises from adaptation of the hemispheric regions, and how assumptions about the corpus callosum influence the recovery process. The chapter presents the intact model. The methods used to simulate callosal lesions in different versions of the model are described, and the resultant effects of callosal lesions of systematically-varied size are presented. The chapter describes the effects of partially/completely removing afferent information to a single hemisphere. This allows establishing that transient impaired performance of the model following callosal lesions is not because of the imbalances in interhemispheric excitationhnhibition, but also to the loss of transmission of specific information between the left and right hemispheric regions through the corpus callosum.