Test–retest stability of electrodermal (EDA) variables
indexing both general autonomic arousal (e.g., skin conductance
level, number of nonspecific skin conductance responses) and
attention to external stimuli (e.g., number of skin conductance
orienting responses, electrodermal responder/nonresponder status)
was assessed in 71 young, recent-onset schizophrenia patients
and 36 demographically matched normal subjects. Significant
stability over a 1-year period was found for both patients and
normal subjects for most EDA variables and for
responder/nonresponder status, with test–retest correlations
generally being higher for normal subjects. The lower reliability
for patients was not attributable to symptomatic fluctuations
during the follow-up period and may reflect poorer arousal
regulation among the patients. Among measures of responding
to nontask stimuli, a simple count of the number of orienting
responses occurring was more stable than was a traditional
trials-to-habituation measure.