Collinear contextual suppression in schizophrenic patients

Schütze, Cathleen; Bongard, Ines; Marbach, Sonja; Brand, Andreas; Herzog, Michael H.

doi:10.1016/j.psychres.2006.03.021

Cited by 20 publications

(15 citation statements)

References 22 publications

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“…While we did not assess thought disorders in the current study, we found no association between clinical rating scale scores (BPRS and SPQ) and task performance, which may be related to the fact that the recruited outpatients were not highly symptomatic. In contrast to our current results, others have found abnormal backward masking in schizophrenia vs. controls during Vernier discrimination, but no difference between groups in the effect of orientation context [45,46]. Previous work has also shown impairments among unaffected relatives of schizophrenia patients during visual backward masking [47].…”

Section: Discussioncontrasting

confidence: 99%

Abnormal Contextual Modulation of Visual Contour Detection in Patients with Schizophrenia

2013

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Schizophrenia patients demonstrate perceptual deficits consistent with broad dysfunction in visual context processing. These include poor integration of segments forming visual contours, and reduced visual contrast effects (e.g. weaker orientation-dependent surround suppression, ODSS). Background image context can influence contour perception, as stimuli near the contour affect detection accuracy. Because of ODSS, this contextual modulation depends on the relative orientation between the contour and flanking elements, with parallel flankers impairing contour perception. However in schizophrenia, the impact of abnormal ODSS during contour perception is not clear. It is also unknown whether deficient contour perception marks genetic liability for schizophrenia, or is strictly associated with clinical expression of this disorder. We examined contour detection in 25 adults with schizophrenia, 13 unaffected first-degree biological relatives of schizophrenia patients, and 28 healthy controls. Subjects performed a psychophysics experiment designed to quantify the effect of flanker orientation during contour detection. Overall, patients with schizophrenia showed poorer contour detection performance than relatives or controls. Parallel flankers suppressed and orthogonal flankers enhanced contour detection performance for all groups, but parallel suppression was relatively weaker for schizophrenia patients than healthy controls. Relatives of patients showed equivalent performance with controls. Computational modeling suggested that abnormal contextual modulation in schizophrenia may be explained by suppression that is more broadly tuned for orientation. Abnormal flanker suppression in schizophrenia is consistent with weaker ODSS and/or broader orientation tuning. This work provides the first evidence that such perceptual abnormalities may not be associated with a genetic liability for schizophrenia.

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Section: Discussioncontrasting

confidence: 99%

Abnormal Contextual Modulation of Visual Contour Detection in Patients with Schizophrenia

2013

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“…Fourth, the shine-through effect is a versatile tool to study complex spatio-temporal processing that was also successfully modeled with a neural network of the Wilson-Cowan type (Herzog, Ernst, Etzold, & Eurich, 2003). For example, we could show that figure-ground segmentation is intact in the schizophrenic patients whereas temporal processing is not (e.g., Herzog et al, 2004;Schutze, Bongard, Marbach, Brand, & Herzog, 2007). The latter two points-rapid and easy applicability and neural explicability-were proposed as additional requirements for an endophenotype (Turetsky et al, 2007).…”

Section: Discussionmentioning

confidence: 92%

Deteriorated visual backward masking in the shine-through effect in adolescents with psychosis

Holzer

Jaugey

Chinet

et al. 2009

Journal of Clinical and Experimental Neuropsychology

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Visual backward masking is a reliable and widely used tool in schizophrenia research. Whereas many studies have shown masking deficits in adult patients, there are only very few studies with adolescents with psychosis-and with controversial results. Masking deficits of adolescents are of primary interest because they are not caused by long-term suffering from the disease and severe medication. We investigated 15 adolescents with psychosis and 19 age-matched controls in the shine-through backward masking paradigm for which strong performance deficits were shown previously in adult schizophrenic patients and their relatives. Adolescents with psychosis were strongly impaired in the shine-through effect compared to controls. This result adds further evidence that backward masking is an endophenotype of schizophrenia.

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“…Then we added additional horizontal lines which undid the deleterious effects of the vertical lines. Again, performance in patients and controls was rather similar (Schütze et al, 2007; Roinishvili et al, 2008). Hence, it seems that spatio-temporal processing is largely intact in the schizophrenic patients—after vernier duration and SOA were adjusted individually.…”

Section: Vision and Schizophrenia: Findings And A Frameworkmentioning

confidence: 87%

Schizophrenia and visual backward masking: a general deficit of target enhancement

Herzog¹,

Roinishvili²,

Chkonia³

et al. 2013

Front. Psychol.

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The obvious symptoms of schizophrenia are of cognitive and psychopathological nature. However, schizophrenia affects also visual processing which becomes particularly evident when stimuli are presented for short durations and are followed by a masking stimulus. Visual deficits are of great interest because they might be related to the genetic variations underlying the disease (endophenotype concept). Visual masking deficits are usually attributed to specific dysfunctions of the visual system such as a hypo- or hyper-active magnocellular system. Here, we propose that visual deficits are a manifestation of a general deficit related to the enhancement of weak neural signals as occurring in all other sorts of information processing. We summarize previous findings with the shine-through masking paradigm where a shortly presented vernier target is followed by a masking grating. The mask deteriorates visual processing of schizophrenic patients by almost an order of magnitude compared to healthy controls. We propose that these deficits are caused by dysfunctions of attention and the cholinergic system leading to weak neural activity corresponding to the vernier. High density electrophysiological recordings (EEG) show that indeed neural activity is strongly reduced in schizophrenic patients which we attribute to the lack of vernier enhancement. When only the masking grating is presented, EEG responses are roughly comparable between patients and control. Our hypothesis is supported by findings relating visual masking to genetic deviants of the nicotinic α7 receptor (CHRNA7).

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Collinear contextual suppression in schizophrenic patients

Cited by 20 publications

References 22 publications

Abnormal Contextual Modulation of Visual Contour Detection in Patients with Schizophrenia

Abnormal Contextual Modulation of Visual Contour Detection in Patients with Schizophrenia

Deteriorated visual backward masking in the shine-through effect in adolescents with psychosis

Schizophrenia and visual backward masking: a general deficit of target enhancement

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