Parameters of the event-related potential are related to functioning in the mentally retarded

Abstract

Event-related potentials were measured in 39 institutionalized profoundly and severely retarded clients divided into two groups: (1) clients assigned to sheltered workshop (WS); and (2) clients, residentially matched, but not assigned to workshop (NSW). Since the groups differed in intelligence (p < 0.01) the ERP was evaluated by analysis of covariance with IQ as the covariate. The WS group had significantly shorter latency of components reflecting initial registration (P1) and channeling (N1) of sensory input and significantly greater amplitude of indices of enhanced perception (P2) and cognitive elaboration (N2). The WS group had significantly more complex waves than the NWS group. A modest (r = 0.31, p < 0.05) relationship between P2 and IQ was observed. Multiple correlations of composite measures of the ERP with IQ were not siginficant but higher in the NWS than WS group. The possibilities that the ERP be used as a supplemental metric for functional evaluation or that the workshop experience might stimulate central nervous system plasticity were discussed.