Work on implicit memory in normal subjects has demonstrated
the influence of stimulus modality on the retrieval of semantic
information. The present study examined the effects of auditory
and visual semantic priming on the recognition of visual words
using a lexical decision task. Performance was studied in a
group of 20 patients with DSM–IV schizophrenia and 26
normal volunteers of similar age and sex. There were two versions
of the task: ipsimodal, in which the word or nonword visual
target followed 400 ms after the onset of a visual word prime
which may or may not be semantically related to the target;
and cross-modal, in which the visual target followed 400 ms
after the onset of an auditory word prime. Both groups showed
significant priming in both modality conditions, although the
schizophrenia patients exhibited significantly greater priming
in the cross-modal condition. Priming effects in the ipsimodal
condition did not differ substantially between patients and
controls. The priming effects in the two conditions correlated
with each other in the schizophrenia patients only. The results
suggest that priming may occur through amodal semantic
representations. In schizophrenia, there appears to be increased
cross-modal connectivity (reduced modality modularity and
informational encapsulation) between lexical representations
that could result in impaired language, particularly speech,
processing. (JINS, 2002, 8, 884–892.)