N400 and P300 modulation as functions of processing level in schizophrenia patients exhibiting formal thought disorder

Laurent, Jean‐Paul; Kostova, Milena; Passerieux, Christine

doi:10.1016/j.ijpsycho.2009.10.001

Cited by 13 publications

(11 citation statements)

References 41 publications

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“…The preponderance of previous studies using these SOAs has suggested less than normal activation of concepts related to the prime in patients with schizophrenia as reflected in larger than normal N400 amplitudes in response to related targets and smaller than normal N400 semantic priming effects (Condray et al 2003;Condray et al 2010;Ditman and Kuperberg 2007;Kiang et al 2011;Kiang et al 2008;Kostova et al 2005;Kostova et al 2003;Laurent et al 2010;Mathalon et al 2010;Ohta et al 1999;Salisbury 2010;Salisbury 2008;Strandburg et al 1997). In contrast, our results-namely, smaller than normal N400 amplitudes to both related and unrelated targets-were consistent with heightened activation within semantic memory of concepts both related and unrelated to the prime.…”

Section: Discussionsupporting

confidence: 78%

“…Numerous studies have found evidence for larger (more negative) than normal N400 amplitudes in response to contextually related items, and smaller than normal N400 semantic priming effects, in schizophrenia (Condray et al 2003;Condray et al 2010;Ditman and Kuperberg 2007;Kiang et al 2011;Kiang et al 2008;Kostova et al 2005;Kostova et al 2003;Laurent et al 2010;Mathalon et al 2010;Ohta et al 1999;Salisbury 2010;Salisbury 2008;Strandburg et al 1997). In contrast, a few other schizophrenia studies have found smaller than normal N400 amplitudes to contextually related targets and increased N400 relatedness priming effects (Kreher et al 2009;Kreher et al 2008;Mathalon et al 2002;Salisbury 2008).…”

Section: Introductionmentioning

confidence: 99%

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Association of abnormal semantic processing with delusion-like ideation in frequent cannabis users: an electrophysiological study

et al. 2012

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Rationale-Frequent cannabis use is a risk marker for schizophrenia and delusions, but the neurocognitive mechanisms of this relationship remain unclear.Objectives-We sought evidence that cannabis users have deficits in processing relationships between meaningful stimuli, similar to abnormalities reported in schizophrenia, and that these deficits are associated with delusion-like ideation. We used the N400 event-related brain potential (ERP) waveform as a neurophysiological probe of activation of concepts in semantic memory. We hypothesized that cannabis users would exhibit larger (more negative) than normal N400 amplitudes in response to stimuli meaningfully related to a preceding prime-reflecting deficient activation of concepts related to the prime. We further hypothesized that the magnitude of this abnormality would correlate with severity of delusion-like ideation.Methods-We recorded ERPs in 24 frequent cannabis users and 24 non-using comparison participants who viewed prime words followed by targets which were either words related or unrelated to the prime or pronounceable non-words. The participants' task was to indicate whether the target was a word. Delusion-like ideation was measured via the Schizotypal Personality Questionnaire.Results-Contrary to our hypothesis, cannabis users exhibited smaller than normal N400s to both related and unrelated targets. These abnormalities correlated with delusion-like ideation in cannabis users only. Conclusions-The results are consistent with a generalized abnormality of activation within semantic memory neural networks in cannabis users. Further research is needed to investigate whether such an abnormality plays a role in the development of delusion-like ideation in cannabis users.

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Section: Discussionsupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Association of abnormal semantic processing with delusion-like ideation in frequent cannabis users: an electrophysiological study

et al. 2012

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“…Among existing studies, none reported a smaller N400 peak latency in patients with schizophrenia; one recent study reported a larger N400 peak latency in patients with schizophrenia [26]; and all of the other studies did not report any difference in the peak latency between patients and normal controls [16], [18], [22], [24], [34], [39], [40], [41]. This may suggest a relatively normal speed of automatic semantic activation in patients with schizophrenia.…”

Section: Discussionmentioning

confidence: 93%

Semantic Processing Disturbance in Patients with Schizophrenia: A Meta-Analysis of the N400 Component

et al. 2011

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BackgroundTheoretically semantic processing can be separated into early automatic semantic activation and late contextualization. Semantic processing deficits have been suggested in patients with schizophrenia, however it is not clear which stage of semantic processing is impaired. We attempted to clarify this issue by conducting a meta-analysis of the N400 component.MethodsTwenty-one studies met the inclusion criteria for the meta-analysis procedure. The Comprehensive Meta-Analysis software package was used to compute pooled effect sizes and homogeneity.ResultsStudies favoring early automatic activation produced a significant effect size of −0.41 for the N400 effect. Studies favoring late contextualization generated a significant effect size of −0.36 for the N400 effect, a significant effect size of −0.52 for N400 for congruent/related target words, and a significant effect size of 0.82 for the N400 peak latency.ConclusionThese findings suggest the automatic spreading activation process in patients with schizophrenia is very similar for closely related concepts and weakly or remotely related concepts, while late contextualization may be associated with impairments in processing semantically congruent context accompanied by slow processing speed.

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“…Biological evidence for a neural basis of FTD has been provided by methods employing functional measures of brain activity. EEG studies employing the n400, an event-related potential (ERP) that is a neural marker of semantic processing [16–18], demonstrated a reduction in n400 amplitudes and increased latency in schizophrenia during a sentence processing task [19–21], consistent with impairment in semantic integration, particularly associated with FTD [22–26]. …”

Section: Introductionmentioning

confidence: 99%

Faulty Suppression of Irrelevant Material in Patients with Thought Disorder Linked to Attenuated Frontotemporal Activation

Arcuri

Broome

Giampietro

et al. 2012

Schizophrenia Research and Treatment

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Formal thought disorder is a feature schizophrenia that manifests as disorganized, incoherent speech, and is associated with a poor clinical outcome. The neurocognitive basis of this symptom is unclear but it is thought to involve an impairment in semantic processing classically described as a loosening of meaningful associations. Using a paradigm derived from the n400 event-related, potential, we examined the extent to which regional activation during semantic processing is altered in schizophrenic patients with formal thought disorder. Ten healthy control and 18 schizophrenic participants (9 with and 9 without formal thought disorder) performed a semantic decision sentence task during an event-related functional magnetic resonance imaging experiment. We employed analysis of variance to estimate the main effects of semantic congruency and groups on activation and specific effects of formal thought disorder were addressed using post-hoc comparisons. We found that the frontotemporal network, normally engaged by a semantic decision task, was underactivated in schizophrenia, particularly in patients with FTD. This network is implicated in the inhibition of automatically primed stimuli and impairment of its function interferes with language processing and contributes to the production of incoherent speech.

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N400 and P300 modulation as functions of processing level in schizophrenia patients exhibiting formal thought disorder

Cited by 13 publications

References 41 publications

Association of abnormal semantic processing with delusion-like ideation in frequent cannabis users: an electrophysiological study

Association of abnormal semantic processing with delusion-like ideation in frequent cannabis users: an electrophysiological study

Semantic Processing Disturbance in Patients with Schizophrenia: A Meta-Analysis of the N400 Component

Faulty Suppression of Irrelevant Material in Patients with Thought Disorder Linked to Attenuated Frontotemporal Activation

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