The electrodermal component of the orienting response in blind and deaf individuals.

Skin conductance response (SCR) was monitored as an index of the orienting response (OR) to a series of 20 tones presented to blind and sighted schoolchildren. Blind children showed fewer criterion SCRs than sighted children, and significantly more of the blind sample exhibited SCR habituation. The blind group also demonstrated fewer non-specific SCRs than sighted control subjects, but demonstrated a higher average skin conductance level (SCL). A second experiment found similar effects for deaf versus hearing children presented with simple visual stimulation, save that no significant difference was observed between these groups in SCL. These results can be explained by assuming that loss of modality results in more efficient development of a neuronal model of the salient features of stimuli impinging on the remaining intact modalities. An explanation in terms of the assessed significance of the stimulus situation can also be entertained. The atypical skin conductance activity of three of the blind group was given separate consideration.