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Abstract:
Abstract: This study used a startle blink paradigm to
investigate the extent to which schizophrenia patients demonstrate
patterns of affective response similar to those of normal
comparison subjects. It has been reliably established that the
startle reflex is modulated by the affective valence of the
foreground stimuli, such that startle blink magnitude is enhanced
while viewing unpleasant images and diminished during presentation
of pleasant images, relative to neutral conditions (Bradley et al.,
1993, Psychophysiology, 30, 541-545). Startle probes were presented
at six different intervals during the viewing of pleasant,
unpleasant and neutral images. Startle blink, EEG, and heart rate
(HR) were recorded from 15 clinically-stable schizophrenia patients
and 14 normal comparison subjects. The groups did not differ in
rating the valence of the images, with unpleasant images rated as
significantly less pleasant than neutral or pleasant stimuli. Both
groups showed the expected pattern of affective modulation of the
startle reflex. Additionally, there were no significant group
differences in HR deceleration whereby both groups showed greatest
deceleration while viewing unpleasant images. There was a tendency,
however, for patients' P300 amplitude to exhibit less
differentiation between valence conditions than that of comparison
subjects. These findings suggest that many aspects of emotional
responsivity in schizophrenia patients are intact, with the
possible exception of attentional engagement as reflected by
P300.
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