Investigating thought disorder in schizophrenia with the lexical decision task

Prior work has found evidence of hyperpriming in schizophrenics, which has been related to a persistence of associational activation in thought disorder. We extended this work by administering a lateralized version of the lexical decision task to 10 thought-disordered schizophrenics (TD), 10 non-thought-disordered schizophrenics (NTD), and 11 control subjects to localize the patterns of priming. All subjects were right-handed males. Associated, unassociated, and neutral prime-target pairs were displayed across seven stimulus location combinations: prime and target both presented to the center, left visual field (LVF), or right visual field (RVF); prime presented to the center with target presented to the LVF or RVF; and prime and target presented contralaterally. TD schizophrenics exhibited priming effects comparable to those of the other subject groups, suggesting intact semantic memory structures and memory processes that may be unimpaired under the conditions studied. It is believed that the associative process mediating priming effects found in schizophrenia are later in the sequence than those examined in this study.