Retarded habituation and lateral asymmetries in electrodermal activity in cardiovascular disorders

Electrodermal activity was recorded bilaterally during a sequence of moderate-intensity tones in 40 cardiac patients who exhibited clinical signs of exhaustion and in 40 controls. Responsive patients were slower to habituate than responsive controls. The groups did not differ in non-specific responses. Patients also showed lateral asymmetries in amplitudes and latencies indicative of abnormalities in right hand activity. Levels of skin conductance were higher in patients largely because of an abnormal elevation of right hand levels in both responders and non-responders. The results were consistent with limbic dysfunction together with a loss of left hemispheric contralateral inhibition. The deficit in habituation and the laterality effect may relate to the role of effort and exhaustion in cardiovascular disorders.