Reconciling stable asymmetry with recovery of function: an adaptive systems perspective on functional plasticity

This article examines alternative ways of resolving an apparent paradox that has emerged from neuropsychological studies of language development: How can the developmentally stable functional asymmetry ("hemispheric specialization") observed in neurologically intact children be reconciled with the dramatic recovery of function often displayed following unilateral brain damage? The alternative resolutions we consider differ most critically in the roles they assign to lesion-induced neural reorganizations versus lesion-related release of preexisting functional potentials. Though arguments are given in favor of the latter as the primary factor in functional recovery, the primary goal of the article is to clarify the conceptual issues raised by recent empirical research.