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p<.007). From a stepwise regression of clusters, bizarre behaviour stood out across mea-
sures (Figure 4). However, delusions also had a detracting influence on BA 1-3 scores
(—.82, p =.005) and flat-affect had a detracting influence on the first trial-pair measure
(Figure 4A). For the NP group a linear regression was only significant for unblocking
(Figure 4A vs 4B), but the first step in a backward regression showed that flat-affect
interfered with CB on the first trial-pair measure (—.62, p<.04).
The opposing tendencies for different clusters in the analysis in Figure 4 might imply that
their severity rather than their nature was important. This interpretation for performance on
the first three trial-pairs was supported by the brief psychiatric ratings where total scores
of illness severity, in contrast to component measures, had negative coefficients ( — .79 to
-. 89, p = .02-.002).
Associations with personality features
Having considered the contribution of symptom and state to the differences in infor-
mation processing strategies of PH and NP patients, it is important now to take this
approach further and to consider if these strategies are related to more deeply embedded
characteristics of personality. Analysis of HANES features across all four groups showed:
(a) more lability in PH (N1, vs CON and OCD5 trend vs NP); (b) less need for sociability
in PH (E1, vs NP and CON); and (c) the least extroversion in OCD (E2, vs CON and SCH:
Table 2). As expected psychotic patients scored 10-20 points significantly above healthy
controls on most MMPI measures.
For controls there were no correlations between HANES features and CB measures.
Among MMPI, dimensions only deviate (PD) tendencies interfered (BA 1-3, r=-.56,
p = .03). HANES E2 extroversion features assisted CB in OCD patients, notable for low E2
Figure 4. (A, left) A profile of partial correlations between negative and positive symptom clusters and the first
trial-pair measure of CB which was decreased in both the PH and NP groups. There were no significant
relationships for the NPgroup. ForPH, flat-affect, anhedonia, bizarre behaviour, thought disorder, .05<p<.01.
(B, right) A similar profile for the unblocking measure on which only the NP group showed attenuated CB. There
was no significant relationship for the PH group. For NP, flat-affect, alogia, apathy, anhedonia, attention, bizarre,
thought disorder; p = .OO3-.OOO3.