Td. Blumenthal et Cl. Creps, NORMAL STARTLE RESPONDING IN PSYCHOSIS-PRONE COLLEGE-STUDENTS, Personality and individual differences, 17(3), 1994, pp. 345-355
Some researchers have predicted that subjects with high scores on ques
tionnaires of psychosis-proneness would show deficiencies in the habit
uation and prepulse inhibition of the startle reflex, similar to those
seen with schizophrenics. In two experiments, startle eyeblink EMG wa
s measured in physical anhedonics, perceptual aberrators, and normal c
ontrols. In Experiment 1 (N = 64), eyeblink amplitude and probability
habituated to both 85 and 100 dB SPL acoustic pulses. In Experiment 2
(N = 48), acoustic prepulses at intensities of 55 or 70 dB SPL were pr
esented with stimulus onset asynchronies (SOAs) of 60 or 120 msec befo
re startle-eliciting stimuli at intensities of 85 and 100 dB SPL. Inhi
bition of startle was generally more pronounced when the prestimulus w
as more intense and at a longer SOA, and when the eliciting stimulus w
as more intense (for response amplitude). In both experiments, startle
responses were larger and more probable for more intense eliciting st
imuli. Also, the diagnosis group variable had no significant effect in
either experiment. These results demonstrate that college students wh
o produce high scores on scales of psychosis-proneness may not provide
a good model for the perceptual gating deficits which have been demon
strated in schizophrenic patients, with regard to automatic measures o
f stimulus processing.