Negative Features, Retrieval Processes and Verbal Fluency in Schizophrenia

Allen, Heidi; Liddle, Peter F.; Frith, C. D.

doi:10.1192/bjp.163.6.769

Cited by 257 publications

(157 citation statements)

References 20 publications

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“…Word approximation gives the hearer the distinct impression that the entire normal vocabulary is not at the speaker's immediate disposal. Allen et al (1993) attribute reduced verbal fluency in schizophrenia to impaired lexical retrieval. In several experiments, none of the vocabulary was actually unavailable, but access to it was inefficient.…”

Section: Pragmatic Disorders Distinct From Aphasiamentioning

confidence: 99%

Schizophrenia and the structure of language: The linguist's view

Covington

Brown

et al. 2005

Schizophrenia Research

302

223

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Patients with schizophrenia often display unusual language impairments. This is a wide ranging critical review of the literature on language in schizophrenia since the 19th century. We survey schizophrenic language level by level, from phonetics through phonology, morphology, syntax, semantics, and pragmatics.There are at least two kinds of impairment (perhaps not fully distinct): thought disorder, or failure to maintain a discourse plan, and schizophasia, comprising various dysphasia-like impairments such as clanging, neologism, and unintelligible utterances.Thought disorder appears to be primarily a disruption of executive function and pragmatics, perhaps with impairment of the syntax-semantics interface; schizophasia involves disruption at other levels. Phonetics is also often abnormal (manifesting as flat intonation or unusual voice quality), but phonological structure, morphology, and syntax are normal or nearly so (some syntactic impairments have been demonstrated). Access to the lexicon is clearly impaired, manifesting as stilted speech, word approximation, and neologism. Clanging (glossomania) is straightforwardly explainable as distraction by self-monitoring.Recent research has begun to relate schizophrenia, which is partly genetic, to the genetic endowment that makes human language possible. D

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Section: Pragmatic Disorders Distinct From Aphasiamentioning

confidence: 99%

Schizophrenia and the structure of language: The linguist's view

Covington

Brown

et al. 2005

Schizophrenia Research

302

223

View full text Add to dashboard Cite

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“…Dopaminergic effects appear to be more regionally localised than NMDA-glutamatergic effects, and modulate task-relevant selective attention in particular, consistent with the regionally localised and task-related hypersynchronisation in Reality Distortion (Ahveninen et al 2000). By contrast, we speculate that hyposynchronisation in Psychomotor Poverty may reflect cholinergic activity, given that anticholinergic agents produce a reduction in Gamma activity, and that clozapine (antipsychotic medication that is a partial cholinergic agonist) improves cognitive deficits that are most apparent in this syndrome (Allen et al 1993). Bearing in mind the complexity of receptor subtypes, these speculations raise the possibility that abnormal regulation of dopamine or cholinergic activity may represent longer time-scale neuromodulatory attempts to cope with a Disorganisation-related deficit in NMDA activity.…”

Section: Guarding Against Over-inclusive Notionsmentioning

confidence: 61%

Combating fuzziness with computational modeling

Talamini¹,

Meeter²,

Murre³

2003

Behav Brain Sci

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Cognitive neuroscience provides a new conceptual framework for psychiatry by showing how psychological processes arise from neuronal activity (Kandel 1998). Conversely, it is possible that psychiatry will influence the future development of cognitive neuroscience by encouraging a better balance between localist and holistic conceptions of brain function. An apparent conflict between these conceptions has been central to the development of neuroscience, with the emphasis upon locally specialized functions emerging as clearly dominant. Neuroanatomy, neurophysiology, neuropsychology, and neuroimaging all show that different regions of the brain process information about different things, and that different cells within regions deal with different aspects of those things. Recent developments in experimental and theoretical neurobiology, however, are leading to an increased emphasis upon interactions that coordinate the activity of locally specialized processors. Here we argue that impairment of these coor-BEHAVIORAL AND BRAIN SCIENCES (2003) Abstract:The concept of locally specialized functions dominates research on higher brain function and its disorders. Locally specialized functions must be complemented by processes that coordinate those functions, however, and impairment of coordinating processes may be central to some psychotic conditions. Evidence for processes that coordinate activity is provided by neurobiological and psychological studies of contextual disambiguation and dynamic grouping. Mechanisms by which this important class of cognitive functions could be achieved include those long-range connections within and between cortical regions that activate synaptic channels via NMDAreceptors, and which control gain through their voltage-dependent mode of operation. An impairment of these mechanisms is central to PCP-psychosis, and the cognitive capabilities that they could provide are impaired in some forms of schizophrenia. We conclude that impaired cognitive coordination due to reduced ion flow through NMDA-channels is involved in schizophrenia, and we suggest that it may also be involved in other disorders. This perspective suggests several ways in which further research could enhance our understanding of cognitive coordination, its neural basis, and its relevance to psychopathology.Keywords: attention; cerebral cortex; cognitive coordination; cognitive neuropsychiatry; cognitive neuropsychology; context disorganization; Gamma rhythms; Gestalt theory; glutamate; grouping; memory; NMDA-receptors; PCP-psychosis; perceptual organization; schizophrenia William A. Phillips, Ph.D., is Professor of Neuropsychology at the University of Stirling, Scotland UK. He has published more than 70 papers on vision, visual memory, perceptual learning, childrens drawings, the effects of brain damage on reading and writing, and the theory of neuronal computation. He was a founder and the first Director of the Center for Cognitive and Computational Neuroscience at the University of Stirling.Steven M. Silverstein, Ph.D., is A...

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“…The disproportionate impairment in semantic fluency found in SZ may have been caused by insufficient access and retrieval capabilities (due to the difficulty in selecting words for clustering) and by inhibiting distractors (resulting from increased SNR) 36 rather than by reduced semantic function in SZ per se. 11,15,33 The weak correlation between the number of RW and the working memory-associated trend to increase switching is consistent with working memory models and represents a measure of the inability to focus and/or inhibit distracting information. Instead of being a reflection of insufficient semantic store or absence of search and retrieval strategies, these deficits are the consequence of the ways in which the impairment of the executive function manifests itself.…”

Section: Discussionmentioning

confidence: 94%

“…17 With this in mind, it is possible to speculate that both groups generated more words in the semantic fluency task because of the broader activation range (there is more to choose from), and that SZ patients were proportionally worse at semantic clustering due to their inability to distinguish between signals (more competition). Furthermore, this would explain why SZ performance improves with cuing, 11 task repetition, 15,33 or prior organization strategies. 29 More specifically, these tactics reduce ''executive'' demands, enabling Data presented as mean 6 standard deviation, unless otherwise specified.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, it is still debatable whether verbal fluency deficits in SZ are caused predominantly by the structure of semantic knowledge [12][13][14] or by inefficient search and retrieval strategies. 10,15,16 Semantic categorizations are used more frequently because they are based on meaning. Bokat et al 12 argue that these categorizations should facilitate fluency as signals become more automatic.…”

Section: Introductionmentioning

confidence: 99%

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Is semantic verbal fluency impairment explained by executive function deficits in schizophrenia?

Berberian

Moraes

Gadelha

et al. 2016

Rev. Bras. Psiquiatr.

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Objective: To investigate if verbal fluency impairment in schizophrenia reflects executive function deficits or results from degraded semantic store or inefficient search and retrieval strategies. Method: Two groups were compared: 141 individuals with schizophrenia and 119 healthy age and education-matched controls. Both groups performed semantic and phonetic verbal fluency tasks. Performance was evaluated using three scores, based on 1) number of words generated; 2) number of clustered/related words; and 3) switching score. A fourth performance score based on the number of clusters was also measured. Results: Individuals with schizophrenia produced fewer words than controls. After controlling for the total number of words produced, a difference was observed between the groups in the number of cluster-related words generated in the semantic task. In both groups, the number of words generated in the semantic task was higher than that generated in the phonemic task, although a significant group vs. fluency type interaction showed that subjects with schizophrenia had disproportionate semantic fluency impairment. Working memory was positively associated with increased production of words within clusters and inversely correlated with switching. Conclusion: Semantic fluency impairment may be attributed to an inability (resulting from reduced cognitive control) to distinguish target signal from competing noise and to maintain cues for production of memory probes.

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Negative Features, Retrieval Processes and Verbal Fluency in Schizophrenia

Cited by 257 publications

References 20 publications

Schizophrenia and the structure of language: The linguist's view

Schizophrenia and the structure of language: The linguist's view

Combating fuzziness with computational modeling

Is semantic verbal fluency impairment explained by executive function deficits in schizophrenia?

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