Heterogeneity in cognitive functioning of schizophrenic patients evaluated by a lexical decision task

Abstract

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.

Semantic priming in schizophrenia: A review and synthesis

“…A French research group, in two LDT studies with similar conditions, has found TD participants unable as a group to demonstrate a significant semantic priming effect, in contrast to non-TD schizophrenia participants, psychiatric controls or normal controls Passerieux et al, 1997). In these studies the SOA was 500 ms and relatedness proportion was 50% (though in Passerieux et al they indicate that the "proportion of related prime-target pairs was 16.7%," this figure appears to be the proportion of total pairs of letter strings, i.e., including pairs with nonwords, that are related word pairs).…”

“…TD schizophrenia groups have been found to demonstrate enhanced semantic priming (Henik et al, 1995;Manschreck et al, 1988;Spitzer et al, 1993a;1993b;Weisbrod et al, 1998), semantic priming comparable to those of non-TD schizophrenia groups or controls (Barch et al, 1996;Blum & Freides, 1995), or reduced semantic priming effects compared to those of non-TD schizophrenia groups or controls Besche et al, 1997;Henik et al, 1992;Passerieux et al, 1997). In addition, Spitzer's group has reported on a non-clinical participant sample among whom high scorers on a scale derived from the language-related complaints of schizophrenia patients showed significantly increased semantic priming compared to the low scorers on this scale (Moritz et al, 1999).…”

“…In almost all of these studies, the TD criterion consists of an arbitrary threshold score (which is not standardized across studies) on a single item from a symptom rating scale (see Bhandari & Curtis, 1998, as well as Spitzer, 1998. Furthermore, direct statistical comparison between TD and non-TD schizophrenia groups has generally been lacking, with few exceptions Passerieux et al, 1997;Spitzer et al, 1993aSpitzer et al, , 1994. In these few studies, the sample sizes are small , significant effects are abolished upon conversion to percentage semantic priming scores (this applies to indirect semantic priming in Spitzer et al, 1993a), data is pooled across conditions for statistical analysis (Spitzer et al, 1994) or the condition (e.g., SOA) is unspecified .…”

“…Therefore attempts to associate TD to semantic priming effects should involve a more detailed and reliable assessment of the schizophrenia participant sample. Several researchers have begun to address this issue Besche et al, 1997;Blum & Freides, 1995;Passerieux et al, 1997).…”

Semantic Dysfunction in Women With Schizotypal Personality Disorder

“…The hypothesis of dysfunction in automatic activation within semantic networks assumes that the initial activation is faster acting and/or spreads too far, which results in loose associations and derailed thinking (17)(18)(19)(20). The hypothesis of disturbed controlled processes assumes that semantic dysfunction manifests itself later, when the processes of integrating a prior semantic context come into play (21)(22)(23)(24)(25)(26)(27). This inability to maintain the prior context or task-relevant information could produce speech marked by loose and bizarre associations.…”