Associative semantic network dysfunction in thought-disordered schizophrenic patients: Direct evidence from indirect semantic priming

Spitzer, Manfred; Braun, Ursula; Hermle, Leo; Maier, Sabine

doi:10.1016/0006-3223(93)90054-h

Cited by 330 publications

(272 citation statements)

References 24 publications

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“…Greater priming is thought to reflect greater activation of the target by the prime. Consistent with increased spread of activation to weak associates, an abnormally large priming effect for indirectly related words has been found in thought-disordered schizophrenia patients, although only when the prime-target interval (or stimulus-onset asynchrony (SOA)) is relatively short (≤300 ms) (Moritz et al, 2001;Moritz et al, 2003;Spitzer et al, 1993).…”

Section: Introductionmentioning

confidence: 74%

Electrophysiological insights into conceptual disorganization in schizophrenia

Kiang

Kutas

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et al. 2007

Schizophrenia Research

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Disorganized speech, or thought disorder, in schizophrenia may reflect abnormal processing of meaningful concepts. To examine whether schizophrenia involves abnormalities in how a meaningful context influences processing of concepts strongly, weakly, or not related to it, we used the N400, an event-related brain potential (ERP) index of semantic relatedness. ERPs were recorded from schizophrenia patients (n=18) and normal controls (n=18) while they viewed category definitions (e.g., a type of fruit), each followed by a target word that was either a hightypicality category exemplar (apple), low-typicality exemplar (cherry), or non-exemplar (clamp). Participants' task was to indicate via button-press whether or not the target belonged to the category. In both patients and controls, N400 amplitude was largest (most negative) for nonexemplars, intermediate for low-typicality exemplars, and smallest (least negative) for hightypicality exemplars. Compared to controls, patients showed a trend toward reduced N400 amplitude differences between non-exemplars and low-typicality exemplars. Most importantly, within patients, reduced N400 amplitude differences between high-and low-typicality exemplars were correlated with psychotic symptoms. In schizophrenia patients, an N400 index of semantic processing was associated with psychotic symptoms. Psychosis may be associated with greater similarity in how concepts strongly and weakly meaningfully related to their context are processed.

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Section: Introductionmentioning

confidence: 74%

Electrophysiological insights into conceptual disorganization in schizophrenia

Kiang

Kutas

Light

et al. 2007

Schizophrenia Research

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“…In contrast to deficits in contextual processing, schizophrenia patients have shown intact or amplified effects of associative relations between words in a two-word priming paradigm (Manschreck et al, 1988;Spitzer et al, 1993;Barch et al, 1996), when priming does not depend on controlled strategic processes induced by task demands (Kreher et al, 2009). In addition, there is evidence for increased sensitivity to lexical associations when the demands of maintaining the language context are higher, as in discourse comprehension .…”

Section: Introductionmentioning

confidence: 99%

Spared and Impaired Spoken Discourse Processing in Schizophrenia: Effects of Local and Global Language Context

et al. 2013

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Individuals with schizophrenia are impaired in a broad range of cognitive functions, including impairments in the controlled maintenance of context-relevant information. In this study, we used ERPs in human subjects to examine whether impairments in the controlled maintenance of spoken discourse context in schizophrenia lead to overreliance on local associations among the meanings of individual words. Healthy controls (n ϭ 22) and patients (n ϭ 22) listened to short stories in which we manipulated global discourse congruence and local priming. The target word in the last sentence of each story was globally congruent or incongruent and locally associated or unassociated. ERP local association effects did not significantly differ between control participants and schizophrenia patients. However, in contrast to controls, patients only showed effects of discourse congruence when targets were primed by a word in the local context. When patients had to use discourse context in the absence of local priming, they showed impaired brain responses to the target. Our findings indicate that schizophrenia patients are impaired during discourse comprehension when demands on controlled maintenance of context are high. We further found that ERP measures of increased reliance on local priming predicted reduced social functioning, suggesting that alterations in the neural mechanisms underlying discourse comprehension have functional consequences in the illness.

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“…A number of characteristics of schizophrenic speech, loose associations, indirect associations, and overly concrete or overly abstract thinking have suggested to investigators that semantic processing, and in particular, spreading activation between concepts, is abnormal in schizophrenia (e.g., Spitzer et al, 1993;Maher, 1983). Nestor et al (1998) previously reported evidence of associational abnormalities using a cued word recall task with word pairs that varied according to an empirically derived concept called connectivity (Nelson et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

“…Maher (1983), Spitzer et al (1993), and Spitzer (1997) have suggested that the associative intrusions and derailments characteristic of schizophrenic speech might reflect, in part, an overactive semantic priming effect. Assuming for healthy individuals active associations quickly decay or are inhibited, thus preventing them from intruding into discourse, they believed that schizophrenic patients might have a disruption in the decay or inhibitory process and thus show an aberrant spread of activation through semantic networks.…”

Section: Introductionmentioning

confidence: 99%

Functional neuroimaging of word priming in males with chronic schizophrenia

et al. 2007

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Word-priming studies have suggested that the associative disturbance of schizophrenia may reflect aberrant spread of activation through the lexicon of the brain. To explore this, we examined lexical activation using a semantic word-priming paradigm coupled with functional magnetic resonance imaging (fMRI). We also wanted to determine whether brain activation to this paradigm correlated with relevant clinical symptom measures. In addition to completing clinical symptom measures, twelve chronic patients and twelve demographically-matched control subjects completed a lexicaldecision semantic-priming paradigm developed as an event-related BOLD fMRI task. This paradigm consisted of words that differed in connectivity. Words with many connections between shared semantic associates are considered high in connectivity and produce the largest behavioral semantic priming effects in control subjects, while words with few connections between shared semantic associates are considered low in connectivity and produce a relatively smaller amount of semantic priming. In fMRI, a respective step-wise increase in activation from high connectivity to low connectivity to unrelated word pairs was expected for normal subjects. Controls showed the expected pattern of activation to word connectivity; however, patients showed a less robust pattern of activation to word connectivity. Furthermore, this aberrant response correlated with measures of Auditory Hallucinations, Distractive Speech, Illogicality, and Incoherence. The patients did not display left frontal and temporal activation as a function of the degree of word connectivity as seen in healthy controls. This may reflect a disease-related disturbance in functional connectivity of lexical activation, which in turn may be associated with clinical symptomatology.

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Associative semantic network dysfunction in thought-disordered schizophrenic patients: Direct evidence from indirect semantic priming

Cited by 330 publications

References 24 publications

Electrophysiological insights into conceptual disorganization in schizophrenia

Electrophysiological insights into conceptual disorganization in schizophrenia

Spared and Impaired Spoken Discourse Processing in Schizophrenia: Effects of Local and Global Language Context

Functional neuroimaging of word priming in males with chronic schizophrenia

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