Reduced binocular depth inversion in schizophrenic patients

Schneider, Udo; Borsutzky, Mathias; Seifert, J.; Leweke, F. Markus; Huber, Thomas J.; Rollnik, Jens D.; Emrich, H. M.

doi:10.1016/s0920-9964(00)00172-9

Cited by 95 publications

(71 citation statements)

References 23 publications

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“…Critically, however, most researchers agree that these visual illusions can be explained by processes within the visual system, rather than by influences on visual function from higherlevel knowledge areas outside the visual system. Our findings are therefore not at odds with decreased susceptibility to some visual illusions in schizophrenic patients (37,38,40,41). In fact, we argue that our findings dovetail with and complement these previous results in a surprising way: independently of the underlying mechanisms, atypicalities within the visual system result in the outputs of the perceptual analysis being less well structured and less adaptive.…”

Section: Discussionsupporting

confidence: 87%

“…In schizophrenia, one important diagnostic category associated with psychosis, both increased and decreased susceptibility to various visual illusions is observed (37)(38)(39)(40)(41). Although most studies implicate atypicalities in early visual function as the source of these differences, some authors argue that certain illusions rely on some form of top-down processing (40,41), a claim that has been contested (42,43).…”

Section: Discussionmentioning

confidence: 99%

“…Although most studies implicate atypicalities in early visual function as the source of these differences, some authors argue that certain illusions rely on some form of top-down processing (40,41), a claim that has been contested (42,43). Critically, however, most researchers agree that these visual illusions can be explained by processes within the visual system, rather than by influences on visual function from higherlevel knowledge areas outside the visual system.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Teufel

Subramaniam

Dobler

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

236

240

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Many neuropsychiatric illnesses are associated with psychosis, i.e., hallucinations (perceptions in the absence of causative stimuli) and delusions (irrational, often bizarre beliefs). Current models of brain function view perception as a combination of two distinct sources of information: bottom-up sensory input and top-down influences from prior knowledge. This framework may explain hallucinations and delusions. Here, we characterized the balance between visual bottom-up and top-down processing in people with early psychosis (study 1) and in psychosis-prone, healthy individuals (study 2) to elucidate the mechanisms that might contribute to the emergence of psychotic experiences. Through a specialized mental-health service, we identified unmedicated individuals who experience early psychotic symptoms but fall below the threshold for a categorical diagnosis. We observed that, in early psychosis, there was a shift in information processing favoring prior knowledge over incoming sensory evidence. In the complementary study, we capitalized on subtle variations in perception and belief in the general population that exhibit graded similarity with psychotic experiences (schizotypy). We observed that the degree of psychosis proneness in healthy individuals, and, specifically, the presence of subtle perceptual alterations, is also associated with stronger reliance on prior knowledge. Although, in the current experimental studies, this shift conferred a performance benefit, under most natural viewing situations, it may provoke anomalous perceptual experiences. Overall, we show that early psychosis and psychosis proneness both entail a basic shift in visual information processing, favoring prior knowledge over incoming sensory evidence. The studies provide complementary insights to a mechanism by which psychotic symptoms may emerge.visual perception | psychosis | top-down processing | predictive coding | schizophrenia

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Teufel

Subramaniam

Dobler

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

236

240

View full text Add to dashboard Cite

show abstract

“…In the same vein, schizophrenia patients are more likely to perceive the image of a concave face when presented using the Binocular Depth Inversion Test (BDIT), rather than automatically invert the image into a standard convex face, as healthy controls typically do [108]. Interestingly, scores on the BDIT correlate with severity of psychotic symptoms [109], which is often not the case with more standard tests of cognition. These findings are all consistent with the notion of a failure to make accurate "topdown" predictions based on contextual information (drawing on memory-based processes) and an overreliance on lower level perceptual processing.…”

Section: Possible Phenomenological Correlatesmentioning

confidence: 99%

Towards integrating phenomenology and neurocognition: Possible neurocognitive correlates of basic self-disturbance in schizophrenia

Nelson

Sass

2017

Current Problems of Psychiatry

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Phenomenological research indicates that disturbance of the basic sense of self may be a core phenotypic marker of schizophrenia spectrum disorders. Basic self-disturbance refers to disruption of the sense of ownership of experience and agency of action and is associated with a variety of anomalous subjective experiences. Little is known about the neurocognitive correlates of basic selfdisturbance. In this paper, we review recent phenomenological and neurocognitive research and point to a convergence of these approaches around the concept of self-disturbance. Specifically, we propose that subjective anomalies associated with basic selfdisturbance may be associated with: 1. source monitoring deficits, which may contribute particularly to disturbances of "ownership" and "mineness" (the phenomenological notion of presence) and 2. aberrant salience, and associated disturbances of memory, prediction, and attention processes, which may contribute to hyper-reflexivity, disturbed "grip" or "hold" on the perceptual and conceptual field, and disturbances of intuitive social understanding ("common sense"). These two streams of research are reviewed in turn before considering ways forward in integrative models, particularly regarding the role of early neurodevelopmental disturbances, primary versus secondary disturbances, and the state versus trait nature of such pathology. Empirical studies are required in a variety of populations in order to test the proposed associations between phenomenological and neurocognitive aspects of self-disturbance in schizophrenia. An integration of findings across the phenomenological and neurocognitive domains would represent a significant advance in the understanding of schizophrenia and possibly enhance early identification and intervention strategies.

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“…Schizophrenic patients have difficulty in perceiving this illusory image, reporting a more veridical judgment. During antipsychotic treatment, the inverted faces were seen as more illusionary (43). This veridical judgment may also be obtained by the administration of psychotomimetic drugs such as nabilone, a ∆ 9 -THC analogue.…”

Section: Clinical Usementioning

confidence: 99%

Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug

Zuardi

Crippa

Hallak

et al. 2006

Braz J Med Biol Res

347

218

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A high dose of ∆ 9 -tetrahydrocannabinol, the main Cannabis sativa (cannabis) component, induces anxiety and psychotic-like symptoms in healthy volunteers. These effects of ∆ 9 -tetrahydrocannabinol are significantly reduced by cannabidiol (CBD), a cannabis constituent which is devoid of the typical effects of the plant. This observation led us to suspect that CBD could have anxiolytic and/or antipsychotic actions. Studies in animal models and in healthy volunteers clearly suggest an anxiolytic-like effect of CBD. The antipsychotic-like properties of CBD have been investigated in animal models using behavioral and neurochemical techniques which suggested that CBD has a pharmacological profile similar to that of atypical antipsychotic drugs. The results of two studies on healthy volunteers using perception of binocular depth inversion and ketamine-induced psychotic symptoms supported the proposal of the antipsychotic-like properties of CBD. In addition, open case reports of schizophrenic patients treated with CBD and a preliminary report of a controlled clinical trial comparing CBD with an atypical antipsychotic drug have confirmed that this cannabinoid can be a safe and well-tolerated alternative treatment for schizophrenia. Future studies of CBD in other psychotic conditions such as bipolar disorder and comparative studies of its antipsychotic effects with those produced by clozapine in schizophrenic patients are clearly indicated.

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Reduced binocular depth inversion in schizophrenic patients

Cited by 95 publications

References 23 publications

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Towards integrating phenomenology and neurocognition: Possible neurocognitive correlates of basic self-disturbance in schizophrenia

Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug

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