Loading…
A Limiting Factor in the "Normalization" of Schizophrenic Orienting Response Dysfunction
Forty schizophrenic patients, 40 nonschizophrenic patients, and 40 normal subjects were given 60 each alternating 1000- and 2000-Hz, 1-second tones at 60 dB. Half of each sample, the Press Group (PG), had to press a pedal to the high (low) target tone, ignoring the nontarget tone. The other half, th...
Saved in:
Published in: | Schizophrenia bulletin 1985, Vol.11 (2), p.230-254 |
---|---|
Main Authors: | , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Forty
schizophrenic patients, 40 nonschizophrenic patients, and 40 normal subjects
were given 60 each alternating 1000- and 2000-Hz, 1-second tones at 60 dB. Half
of each sample, the Press Group (PG), had to press a pedal to the high (low)
target tone, ignoring the nontarget tone. The other half, the Nonpress Groups
(NPGs), were given no reason to attend. Skin conductance response (SCR), finger
pulse volume (FPV), and electroencephalographic (EEG) activity were recorded.
NPG schizophrenic subjects were more often nonresponsive in both SCR and FPV
than other samples, but less often responsive in EEG only when a 20 percent
criterion of alpha blockade was used. Schizophrenic subjects showed greater
consistency of OR nonresponsiveness in SCR and FPV, and nonsignificantly greater
consistency in criterion alpha block, pointing to a deficit in orienting
response (OR) rather than in peripheral response. When the targeted signal was
given, schizophrenic subjects showed the same response as other groups in all
systems. This was not due to an indiscriminate increase in reactivity, since
response increase centered on the targeted signal itself in all groups. As the
target signal was repeated, autonomic OR in schizophrenics declined sharply so
that they again became under responsive. Thus, OR
"normalization" achieved by targeting significant signals is
restricted to relatively early responsiveness. The rapid decline in autonomic OR
may help explain differences in schizophrenic subjects between P300 and
autonomic ORs to significant stimuli. Schizophrenic subjects were no different
from controls in bilateral SCR or FPV asymmetry, but displayed less frequent
criterion alpha blockade and reduced background alpha power in the left
hemisphere. Each system showed a different pattern of bilateral asymmetry,
reflecting complex, not well understood relations among these responses. This
was further emphasized by the fact that skin conductance level (SCL) incremented
over trials in PG subjects, reflecting sustained activation, while EEG
background showed an increase in slower wave power, consistent with reports of
increased drowsiness. The only drug effect seen was a lowering of SCL.
Neuroleptics were associated with a flexible inhibitory control of SCL,
permitting normal-like increment when circumstances required. Depressed
patients' data suggested they might show heightened OR
nonresponsiveness to innocuous stimuli which might not be subject to
"normalization" by manipulation of |
---|---|
ISSN: | 0586-7614 1745-1701 |
DOI: | 10.1093/schbul/11.2.230 |