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This article examines work during the past decades on cognitive processes in schizophrenic patients with regard to word recognition tasks. Results obtained in studies using lexical decision tasks with semantic priming are not clear in schizophrenic patients : some authors argued in favour of a preservation of automatic processing, others found a reduction in semantic priming and claimed a deficit in controlled processes whereas others proposed a preservation of these same processes. From the results obtained with semantic lexical decision tasks, we can consider several factors : the role of clinical variables and more specifically the presence of formal thought disorders ( FTD) in schizophrenic patients, the role of the nature of linguistic context (semantic versus syntactic) , the structure of the material (proportion of related words in a lexical decision task, nature of the semantic links), the nature of experimental paradigms (double lexical decision task or sequential lexical decision task) and the nature of processes (automatic versus controlled). It seems that the controlled (but not automatic) processing of semantic information was neglected by schizophrenic patients with FTD contrary to the processing of syntactic context by the same patients. However, this cognitive abnormality can be corrected either by increasing the proportion of pairs of words with semantic links or by using double lexical decision tasks. These last results suggest that the nature of this cognitive abnormality is functional in schizophrenic patients. We illustrate this proposal with additional studies using new experimental paradigms including event-related potentials (EBPs) .
