Conditioned Blocking: Schizopbrenia
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Insignificant interactions (p>.l) are not reported but the terms “tendency, trend and tend“
refer to significances of p≈.05-.1.
An iterative procedure was adopted for the study of symptom, personality and monoam-
ine measures (cf. Swerdlow et al., 1995). After performing analyses of variance for group
differences, Pearson correlation coefficients were calculated between individual scores and
CB measures. Then hypotheses based on the correlations were examined by linear (and
stepwise) regression using the dependent measures of CB shown to be useful and partial
correlations cited.
Results
Conditioned blocking (CB) and learning
Learning. First learning measures are examined for the potential confound with interpret-
ations in terms of blocking and illumination of the potential group differences in learning
strategy.
Both comparison groups required a similar number of trials to Ieam tasks A and B. An
increased number of trials for the psychotic vs the comparison groups was consistent across
each learning phase (Newman-Keuls, p<.007; Figure 2, left). The removal of outliers
(>3SD) decreased means for NP (not PH) patients by 8%. In each phase of learning, PH
patients needed more trials than both comparison groups, but the effect was less marked
for the NP group.
Exploration search-times (punished with minus points) showed a similar pattern. Psy-
chotic patients spent about three times as long exploring as the others (.04<p<.0001). The
PH group explored for longer than the two comparison groups (p < .003) and again the
effect was less marked for NP patients (Figure 2, middle). Both subgroups spent about
Figure 2. Three learning session measures before testing for CB. ANCOVA for four subject groups with IQ
as covariate (Newman-Keuls post-hoc tests). (Left) Learning trials=M(9,136) = 2.84, p = .004; *in each session
PH>0CD and CON ∕><.002, NP>C0N p<0.03. (Middle) Exploration time=Д15,149)=2.31, p=.006; ∙in
each phase PH>OCD and CONρ<0.003, А-phase NP>CON, В-phase also NP>OCD p<0.03. (Right) Task
length=f(6,112) = 5.34,p≈.0001, PH a∏dNP>OCDand CONp<0.007, PH>NPp<.01.