Low-level temporal coding impairments in psychosis: Preliminary findings and recommendations for further studies.

Schmidt, Heike; Mcfarland, John; Ahmed, Mohamed; McDonald, Colm; Elliott, Mark A.

doi:10.1037/a0023387

Cited by 44 publications

(42 citation statements)

References 20 publications

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“…The current observation that individuals with schizophrenia were less likely to bind auditory and visual information may seem at first glance incompatible with the considerable literature that individuals with the disorder require greater temporal asynchrony between stimuli to dissociate them (Foucher et al, 2007; Giersch et al, 2009; Schmidt et al, 2011). However, the McGurk effect relies on implicit multisensory binding, while judgments of temporal asynchrony are precisely explicit.…”

Section: Discussioncontrasting

confidence: 80%

Eluding the illusion? Schizophrenia, dopamine and the McGurk effect

White

Wigton

Joyce

et al. 2014

Front. Hum. Neurosci.

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Perceptions are inherently probabilistic; and can be potentially manipulated to induce illusory experience by the presentation of ambiguous or improbable evidence under selective (spatio-temporal) constraints. Accordingly, perception of the McGurk effect, by which individuals misperceive specific incongruent visual and auditory vocal cues, rests upon effective probabilistic inference. Here, we report findings from a behavioral investigation of illusory perception and related metacognitive evaluation during audiovisual integration, conducted in individuals with schizophrenia (n = 30) and control subjects (n = 24) matched in terms of age, sex, handedness and parental occupation. Controls additionally performed the task after an oral dose of amisulpride (400 mg). Individuals with schizophrenia were observed to exhibit illusory perception less frequently than controls, despite non-significant differences in perceptual performance during control conditions. Furthermore, older individuals with schizophrenia exhibited reduced rates of illusory perception. Subsequent analysis revealed a robust inverse relationship between illness chronicity and the illusory perception rate in this group. Controls demonstrated non-significant modulation of perception by amisulpride; amisulpride was, however, found to elicit increases in subjective confidence in perceptual performance. Overall, these findings are consistent with the idea that impairments in probabilistic inference are exhibited in schizophrenia and exacerbated by illness chronicity. The latter suggests that associated processes are a potentially worthwhile target for therapeutic intervention.

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Section: Discussioncontrasting

confidence: 80%

Eluding the illusion? Schizophrenia, dopamine and the McGurk effect

White

Wigton

Joyce

et al. 2014

Front. Hum. Neurosci.

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“…Recent research has suggested that perceptual timing abnormalities may be a feature of psychosis more generally rather than of schizophrenia specifically [23]. Consistent with this idea, schizophrenia and psychotic affective disorders, including schizoaffective disorder and psychotic bipolar disorder, show more severe neurocognitive impairment than non-psychotic bipolar disorder [24], [25], which suggests that psychosis symptoms are better predictors of neurocognitive impairments than DSM diagnostic category.…”

Section: Introductionmentioning

confidence: 94%

Increased Timing Variability in Schizophrenia and Bipolar Disorder

et al. 2014

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Theoretical and empirical evidence suggests that impaired time perception and the neural circuitry underlying internal timing mechanisms may contribute to severe psychiatric disorders, including psychotic and mood disorders. The degree to which alterations in temporal perceptions reflect deficits that exist across psychosis-related phenotypes and the extent to which mood symptoms contribute to these deficits is currently unknown. In addition, compared to schizophrenia, where timing deficits have been more extensively investigated, sub-second timing has been studied relatively infrequently in bipolar disorder. The present study compared sub-second duration estimates of schizophrenia (SZ), schizoaffective disorder (SA), non-psychotic bipolar disorder (BDNP), bipolar disorder with psychotic features (BDP), and healthy non-psychiatric controls (HC) on a well-established time perception task using sub-second durations. Participants included 66 SZ, 37 BDNP, 34 BDP, 31 SA, and 73 HC who participated in a temporal bisection task that required temporal judgements about auditory durations ranging from 300 to 600 milliseconds. Timing variability was significantly higher in SZ, BDP, and BDNP groups compared to healthy controls. The bisection point did not differ across groups. These findings suggest that both psychotic and mood symptoms may be associated with disruptions in internal timing mechanisms. Yet unexpected findings emerged. Specifically, the BDNP group had significantly increased variability compared to controls, but the SA group did not. In addition, these deficits appeared to exist independent of current symptom status. The absence of between group differences in bisection point suggests that increased variability in the SZ and bipolar disorder groups are due to alterations in perceptual timing in the sub-second range, possibly mediated by the cerebellum, rather than cognitive deficits.

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“…Events falling within this time window would be perceived as simultaneous even if they were physically asynchronous; whereas events falling within two different units of subjective time would be perceived as asynchronous. If these units of subjective time are altered (as for instance in individuals suffering from first episode psychosis, e.g., [20]), then the processing of temporal event-structure would be compromised, which could in turn adversely affect higher-order functions that rely on accurate sequencing of events, such as action planning and execution [21], [22], language processing [23], and social interaction [24], all functions that are impaired in ASD.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Visual Temporal Resolution in Autism Spectrum Disorders

2012

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Cognitive functions that rely on accurate sequencing of events, such as action planning and execution, verbal and nonverbal communication, and social interaction rely on well-tuned coding of temporal event-structure. Visual temporal event-structure coding was tested in 17 high-functioning adolescents and adults with autism spectrum disorder (ASD) and mental- and chronological-age matched typically-developing (TD) individuals using a perceptual simultaneity paradigm. Visual simultaneity thresholds were lower in individuals with ASD compared to TD individuals, suggesting that autism may be characterised by increased parsing of temporal event-structure, with a decreased capability for integration over time. Lower perceptual simultaneity thresholds in ASD were also related to increased developmental communication difficulties. These results are linked to detail-focussed and local processing bias.

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Low-level temporal coding impairments in psychosis: Preliminary findings and recommendations for further studies.

Cited by 44 publications

References 20 publications

Eluding the illusion? Schizophrenia, dopamine and the McGurk effect

Eluding the illusion? Schizophrenia, dopamine and the McGurk effect

Increased Timing Variability in Schizophrenia and Bipolar Disorder

Enhanced Visual Temporal Resolution in Autism Spectrum Disorders

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