CORTICAL SENSORY EVOKED-POTENTIALS AND COMMUNICATIVE FOREBRAIN FUNCTIONS

Cortical evoked potentials were measured to visual, auditory and somat osensory stimuli in 20 subjects with serious neurodevelopmental impair ments due to various etiologies. The results were compared with behavi oral observations to find out whether the absence/presence of the resp onses corresponded to the level of social functioning. No cortical evo ked potentials were elicited in two subjects, responses to the stimula tion of one modality were missing in three subjects (retinal b-waves a nd brainstem auditory and somatosensory evoked potentials were, howeve r, preserved in them). No communicative behavior was observed in subje cts with absent responses. Ten subjects had marked deviations in the e voked potentials, the behavioral observations in them, ranging from no communication to sentenced speech. Five subjects had normal response patterns and they showed a great variety of communicative skills, incl uding speech. The results support the view that bilateral loss of cort ical somatosensory, visual, and auditory evoked potentials is a sign o f loss of neural substrates of communication.