Background. The disorganization pattern in schizophrenia,
which involves formal thought disorders,
is thought to be correlated with a deficit in integrative
processes of contextual information. We
tested the hypothesis that thought disordered schizophrenics, unlike
non-thought disordered
schizophrenics, would present a deficit in the processing of the context
during a task which involves these integrative processes.
Methods. A group of 22 schizophrenic patients diagnosed in
accordance with DSM-III-R criteria
and a group of 11 control subjects were compared using a semantic priming
version of the lexical
decision task. The experimental design used low-level structuration of
verbal material to reveal the
difficulty that schizophrenic patients encounter in using semantic regularities.
Results. A significant difference in priming effect was found
between the three groups. Control
subjects and non-thought disordered schizophrenics exhibit a priming effect
for related word pairs
when compared with unrelated pairs (respectively F(1,10)=17·7;
P<0·002 and F(1,10)=14·5;
P>0·003) but thought disordered schizophrenics did not
(F(1,10)<1; NS).
Conclusions. This finding provides evidence for the
cognitive heterogeneity of schizophrenic
subjects. This absence of priming effect in thought-disordered
schizophrenic subjects supports the
hypothesis that these patients present a deficit in the post-lexical
controlled information processing
that permits the integration of semantic information.