RESULTS (1) Comparison of baseline autonomic measures between NS and DS (Table 1; n = 15 each; Student t-test for unpaired data): The skin conductance level (SCL) in mS was significantly lower in DS compared with NS (P<.01) and heart rate was significantly higher in DS (P<.01). (2) Comparison of autonomic measures in DS (n = 25) before (5 min) and during exposure to 10 auditory stimuli (5 min) (Table II). The finger plethysmogram amplitude was significantly lower during exposure to sound stimuli compared to before (P<.05). (3) Comparison of number of DS subjects who showed habituation of SSR to the stimuli versus those who did not habituate: The number of subjects who showed abnormal SSRs (i.e., did not show SSRs (n = 10) and no SSR
habituation (n = 7), was not significantly different from the number of subjects who did habituate (n = 8), using the McNemar test (P>.05).