A Stroop negative priming (NP) task was used to assess immediate
selective attention and priming in schizophrenia and
schizoaffective disorder. Subject groups were comprised of 12
state hospital inpatients (41.8 ± 7.5 years of age),
11 outpatients (39.8 ± 7.5 years of age), and 16 controls
(36.4 ± 11.7 years of age). Compared with the control
group and the outpatients, inpatients failed to exhibit NP
[F(2,36) = 6.09, p < .01],
despite exhibiting equivalent Stroop RT interference (p
> .05). Error rates did not differ significantly between
the 3 groups. Although medication types and dosages were similar
between the 2 patient groups, length of illness was significantly
longer in the inpatients (19.8 years) than in the outpatients
(12.4 years; p < .05). Positive symptom ratings
were also significantly higher in the inpatients. The finding
of reduced NP in the state hospital patients appears to be related
to severity of symptomatology and chronicity of illness.
(JINS, 2002, 8, 794–803.)