Brain damage: Functional reorganization

At least four forms of functional neuroplasticity can be studied in patients recovering from brain damage and normal volunteers: (1) homologous area adaptation, (2) cross-modal reassignment, (3) potentiation of topographic representations, and (4) compensatory masquerade. Homologous area adaptation is the assumption of an anatomically predetermined role (e.g., language expression) by the homologous region in the opposite cerebral hemisphere. Cross-modal reassignment occurs when structures previously devoted to processing a particular kind of sensory input begin to process input from a new sensory modality. Potentiation of topographic representations is the topographic modulation of a functional brain region with repeated performance or experience. Compensatory masquerade is the adaptation of a preexisting process to a new behavioral role. By focusing on these four forms of functional neuroplasticity, several fundamental questions about how recovery of function occurs after brain damage can be addressed.