Electrodermal activity in schizophrenia: a quantitative study using a short interstimulus paradigm.
BACKGROUND
Electrodermal activity in response to short interstimulus interval (ISI) stimulation allows aspects of information processing to be examined, but such paradigms cause skin conductance responses (SCRs) to overlap. A signal decomposition method was developed and employed to score the overlapped SCRs. This is the first application of the method to the study of schizophrenia.


METHODS
Electrodermal activity of 30 medicated patients with schizophrenia and 50 normal controls was obtained using a conventional auditory oddball paradigm with an ISI of 1.3 sec. Tonic skin conductance level (SCL), phasic SCRs, SCR temporal dynamics, and a range of SCR variables in response to target tones were examined.


RESULTS
The schizophrenic group showed reduced response rate, proportion of responders, SCR amplitude, rise time, peak latency, and steady-state response amplitude, over the trial compared with controls. There were no between-group differences in SCL or SCR onset time.


CONCLUSIONS
The combined use of a conventional short ISI paradigm and the new SCR scoring method demonstrated new facets of electrodermal hyporeactivity in medicated patients with schizophrenia. The hyporeactivity could not be attributed to changes in tonic arousal or dysfunctions in peripheral sympathetic nerve conductance.
Lim
C L
CL
Department of Neurology, University of Sydney, Australia.
Gordon
E
E
Harris
A
A
Bahramali
H
H
Li
W M
WM
Manor
B
B
Rennie
C
C
D000161:Acoustic Stimulation; D000328:Adult; D000465:Algorithms; D014150:Antipsychotic Agents / Q000627:therapeutic use; D003024:Clozapine / Q000627:therapeutic use; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology*; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology*
D014150:Antipsychotic Agents; D003024:Clozapine