Lack of flexibility in visual grouping in patients with schizophrenia.

Giersch, Anne; Rhein, Virginie

doi:10.1037/0021-843x.117.1.132

Cited by 22 publications

(29 citation statements)

References 54 publications

(65 reference statements)

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“…These grouping mechanisms allow us to attribute object parts to the same object and to put together different objects that belong to a same group, e.g., the trees in a forest. Our results and those reported in the literature show that mildly symptomatic patients with schizophrenia benefit as much as controls from automatic grouping (Chey and Holzman, 1997; Silverstein et al, 1998; Giersch and Rhein, 2008; van Assche and Giersch, 2011), at least when grouping cues are unambiguous and when they do not lead to spurious grouping (see Kurylo et al, 2007; Silverstein and Keane, 2011 for limits to the benefits of automatic grouping in schizophrenia).…”

Section: Introductionsupporting

confidence: 80%

“…The most likely explanation is that healthy participants learned the correspondence between the tap pairs and the visual organization of the visual targets. In the non-congruent condition, this might have been facilitated by the fact that healthy participants are able to build a representation that binds unconnected targets together (Giersch and Rhein, 2008; van Assche et al, 2012). Inasmuch participants “re-grouped” unconnected targets, they quickly learned to expect an absence of connecters between those visual targets that were to be tapped together.…”

Section: Discussionmentioning

confidence: 99%

“…Many studies have shown that patients with schizophrenia have a difficulty organizing visual information through space (Place and Gilmore, 1980; Wells and Leventhal, 1984; Silverstein et al, 2000; Must et al, 2004; Uhlhaas et al, 2006; Kurylo et al, 2007; Giersch and Rhein, 2008; van Assche and Giersch, 2011). These deficits are often correlated to the clinical symptom of disorganization, and might even reflect this symptom [review in Silverstein and Keane (2011)].…”

Section: Introductionmentioning

confidence: 99%

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Combined visual and motor disorganization in patients with schizophrenia

Giersch¹,

Wilquin²,

Lefebvre³

et al. 2013

Front. Psychol.

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Cognitive impairments are difficult to relate to clinical symptoms in schizophrenia, partly due to insufficient knowledge on how cognitive impairments interact with one another. Here, we devised a new sequential pointing task requiring both visual organization and motor sequencing. Six circles were presented simultaneously on a touch screen around a fixation point. Participants pointed with the finger each circle one after the other, in synchrony with auditory tones. We used an alternating rhythmic 300/600 ms pattern so that participants performed pairs of taps separated by short intervals of 300 ms. Visual organization was manipulated by using line-segments that grouped the circles two by two, yielding three pairs of connected circles, and three pairs of unconnected circles that belonged to different pairs. This led to three experimental conditions. In the “congruent condition,” the pairs of taps had to be executed on circles grouped by connecters. In the “non congruent condition,” they were to be executed on the unconnected circles that belonged to different pairs. In a neutral condition, there were no connecters. Twenty two patients with schizophrenia with mild symptoms and 22 control participants performed a series of 30 taps in each condition. Tap pairs were counted as errors when the produced rhythm was inverted (expected rhythm 600/300 = 2; inversed rhythm <1). Error rates in patients with a high level of clinical disorganization were significantly higher in the non-congruent condition than in the two other conditions, contrary to controls and the remaining patients. The tap-tone asynchrony increased in the presence of connecters in both patient groups, but not in the controls. Patients appeared not to integrate the visual organization during the planning phase of action, leading to a large difficulty during motor execution, especially in those patients revealing difficulties in visual organization. Visual motor tapping tasks may help detect those subgroups of patients.

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Section: Introductionsupporting

confidence: 80%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Combined visual and motor disorganization in patients with schizophrenia

Giersch¹,

Wilquin²,

Lefebvre³

et al. 2013

Front. Psychol.

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“…Of course, the foregoing is not meant to imply that all high-level abilities are compromised in schizophrenia. Patients can suppress or enhance selected input (Luck and Gold 2008) or adapt to certain regularities in interelement grouping (Giersch and Rhein 2008). Future studies will need to test CI of closed and open contours (Kovács and Julesz 1993) to see whether CI deficits can be explained in terms of global shape processing (or “closure”) deficits.…”

Section: Discussionmentioning

confidence: 99%

The spatial range of contour integration deficits in schizophrenia

et al. 2012

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Contour integration (CI) refers to the process that represents spatially separated elements as a unified edge or closed shape. Schizophrenia is a psychiatric disorder characterized by symptoms such as hallucinations, delusions, disorganized thinking, inappropriate affect, and social withdrawal. Persons with schizophrenia are impaired at CI, but the specific mechanisms underlying the deficit are still not clear. Here, we explored the hypothesis that poor patient performance owes to reduced feedback or impaired longer-range lateral connectivity within early visual cortex—functionally similar to that found in 5- to 6-year old children. This hypothesis predicts that as target element spacing increases from .7 to 1.4° of visual angle, patient impairments will become more pronounced. As a test of the prediction, 25 healthy controls and 36 clinically stable, asymptomatic persons with schizophrenia completed a CI task that involved determining whether a subset of Gabor elements formed a leftward or rightward pointing shape. Adjacent shape elements were spaced at either .7 or 1.4° of visual angle. Difficulty in each spacing condition depended on the number of noise elements present. Patients performed worse than controls overall, both groups performed worse with the larger spacing, and the magnitude of the between-group difference was not amplified at the larger spacing. These results show that CI deficits in schizophrenia cannot be explained in terms of a reduced spatial range of integration, at least not when the shape elements are spaced within 1.5°. Later-developing, low-level integrative mechanisms of lateral connectivity and feedback appear not to be differentially impaired in the illness.

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“…This would be of significant value, given the occurrence of alterations in visual perception in schizophrenia such as deficient perceptual organisation (Giersch and Rhein 2008;Giersch et al 2011;Silverstein and Keane 2011). Despite frequent reports of poor visual ability in these species (e.g.…”

Section: Future Directionsmentioning

confidence: 98%