Autonomic correlates of chronic schizophrenia: A reaction time paradigm.

Assessed basal, tonic, and 2 phasic measures of heart rate and skin conductance among 16 drug-free, chronic, process, nonparanoid schizophrenics, and 2 groups of control Ss (hospital staff and prison inmates). Of particular interest were changes in autonomic activity that attended manipulation of "go" signal intensity within a reaction time paradigm. Among control Ss, increased signal intensity produced increases in tonic levels and amplitude of anticipatory responding. Among schizophrenics, however, the reverse occurred: Increased signal intensity resulted in decreased tonic levels and inhibition of anticipatory responding. Schizophrenic responses occurred in the absence of basal level differences between groups. Results are interpreted as indicating the presence of a learned anticipatory set that serves to reduce the impact of stimulus intensity. This inhibitory set would also appear to reduce receptivity to the cue component of stimuli. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)