ELECTRODERMAL LEVEL ASYMMETRY IN A UNILATERAL BRAIN-DAMAGED PATIENT

The purpose of this article is to report on a patient with right front al damage who exhibited a strong left > right asymmetry of skin conduc tance levels (SCLs). Comparison with a control group indicates that th is asymmetry resulted only from a higher SCL on the left hand. Such a result suggests that the frontal lesion has induced a contralateral di sinhibition and is consistent with the idea of a contralateral inhibit ory control of tonic electrodermal activity in the case of a healthy h emisphere. Peripheral factors, such as sweating or temperature seem un related to the SCL asymmetry and a possible influence of motor weaknes s is also rejected following comparison with a second patient who pres ented the same motor disorder without atypical SCL asymmetry. In contr ast to SCLs, no asymmetry in skin conductance response amplitudes was observed in the former patient. This discrepancy is in line with previ ous observations showing that tonic and phasic EDA could depend on dif ferent neurophysiological controls. (C) 1998 Elsevier Science B.V. All rights reserved.