Electrophysiological insights into language processing in schizophrenia

Harvard University, Cambridge, Massachusetts, United States
Psychophysiology (Impact Factor: 2.99). 12/2002; 39(6):851-60. DOI: 10.1111/1469-8986.3960851
Source: PubMed


Deficits in language comprehension in schizophrenia were examined using event-related potentials (ERPs). Schizophrenic and healthy participants read sentences in which the first clause ended with a homograph, and the second clause started with a target word that was semantically related to the homograph's dominant meaning (e.g., 1. Diving was forbidden from the bridge because the river had rocks in it. or 2. The guests played bridge because the river had rocks in it.). Processing of the targets (e.g., "river") was expected to be primarily influenced by the preceding overall sentence context (congruent in 1; incongruent in 2) in healthy participants, but to be inappropriately affected by the dominant meaning of homographs (e.g., the "structure" meaning of "bridge") in sentences like 2 in schizophrenic patients. The N400 ERP component that is known to be sensitive to contextual effects during language processing confirmed these predictions. This showed that language abnormalities in schizophrenia may be related to deficient processing of context-irrelevant semantic representations of words from the discourse.

Download full-text


Available from: Gina Kuperberg
  • Source
    • "; Onitsuka, Oribe, Nakamura, & Kanba, 2013; Salisbury, O'Donnell, McCarley, Nestor, & Shenton, 2000; Salisbury, Shenton, Nestor, & McCarley, 2002; Sitnikova, Salisbury, Kuperberg, & Holcomb, 2002). Most ERP studies on context processing in schizophrenia found increased N400 to both congruent and incongruent sentence endings (Nestor et al., 1997; Niznikiewicz et al., 1997; Salisbury et al., 2000, 2002; Sitnikova et al., 2002), suggestive of difficulties in using semantic context. Studies that specifically looked at the processes within semantic networks found evidence for abnormal connectivity within semantic memory (Nestor et al., 1998, 2001) and abnormal structure of semantic knowledge (Kiang, Kutas, Light, & Braff, 2007; Mathalon et al., 2010; Paulsen et al., 1996). "
    [Show abstract] [Hide abstract]
    ABSTRACT: This study used event-related potentials to examine interactions between mood, sentence context, and semantic memory structure in schizophrenia. Seventeen male chronic schizophrenia and 15 healthy control subjects read sentence pairs after positive, negative, or neutral mood induction. Sentences ended with expected words (EW), within-category violations (WCV), or between-category violations (BCV). Across all moods, patients showed sensitivity to context indexed by reduced N400 to EW relative to both WCV and BCV. However, they did not show sensitivity to the semantic memory structure. N400 abnormalities were particularly enhanced under a negative mood in schizophrenia. These findings suggest abnormal interactions between mood, context processing, and connections within semantic memory in schizophrenia, and a specific role of negative mood in modulating semantic processes in this disease.
    Full-text · Article · Aug 2014 · Psychophysiology
  • Source
    • "Despite the heterogeneity of experimental conditions and populations, both Lecardeur et al. (2006) and Minzenberg et al. (2002) concluded that a reduction of the semantic priming effect in schizophrenia was the most robust result reported. This conclusion was consistent with several ERP investigations , which showed a reduced N400 effect in patients with schizophrenia (Sitnikova et al., 2002; Hokama et al., 2003; Kostova et al., 2003, 2005; Kiang et al., 2008). Again, several works failed to find this result, but the majority of ERP investigations in schizophrenia reported an abnormal N400 modulation (Kumar and Debruille, 2004), which suggested disorders in underlying neurocognitive mechanisms. "

    Full-text · Dataset · Dec 2012
  • Source
    • "In summary, the literature on high-level language comprehension in schizophrenia patients shows that they are most impaired when control demands are highest, as when the use of context is needed to constrain word meaning [36] or construct a meaning at odds with the associative relations amongst individual words [37]. These results are suggestive of a role for a cognitive control deficit in abnormal language processing in schizophrenia, leading patients to fail to suppress context-irrelevant information as well as maintain linguistic context in order to guide the processing of incoming words. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Cognitive deficits across a wide range of domains have been consistently observed in schizophrenia and are linked to poor functional outcome (Green, 1996; Carter, 2006). Language abnormalities are among the most salient and include disorganized speech as well as deficits in comprehension. In this review, we aim to evaluate impairments of language processing in schizophrenia in relation to a domain-general control deficit. We first provide an overview of language comprehension in the healthy human brain, stressing the role of cognitive control processes, especially during discourse comprehension. We then discuss cognitive control deficits in schizophrenia, before turning to evidence suggesting that schizophrenia patients are particularly impaired at processing meaningful discourse as a result of deficits in control functions. We conclude that domain-general control mechanisms are impaired in schizophrenia and that during language comprehension this is most likely to result in difficulties during the processing of discourse-level context, which involves integrating and maintaining multiple levels of meaning. Finally, we predict that language comprehension in schizophrenia patients will be most impaired during discourse processing. We further suggest that discourse comprehension problems in schizophrenia might be mitigated when conflicting information is absent and strong relations amongst individual words are present in the discourse context.“There is no “centre of Speech” in the brain any more than there is a faculty of Speech in the mind. The entire brain, more or less, is at work in a man who uses language”William JamesFrom The Principles of Psychology, 1890“The mind in dementia praecox is like an orchestra without a conductor”Kraepelin, 1919
    Full-text · Article · Apr 2012
Show more