Study on the Occurrence and Neural Bases of Hemispatial Neglect With Different Reference Frames

Yue, Yuehong; Song, Weiqun; Huo, Su; Wang, Maobin

doi:10.1016/j.apmr.2011.07.192

Cited by 34 publications

(44 citation statements)

References 38 publications

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“…Moreover, results from a meta-analysis study indicated that, while egocentric symptoms were associated with damage within the perisylvian network and damage within sub-cortical structures, more posterior lesions were associated with allocentric symptoms (Chechlacz et al, 2012a,b). On the other hand, in a study of 110 acute right hemisphere patients (Yue et al, 2012) allocentric neglect was only observed in conjunction with egocentric neglect. Likewise, Rorden et al (2012) examined 36 patients with continuous measures for these deficits and found a strong association between the severity of egocentric and allocentric neglect.…”

Section: Introductionmentioning

confidence: 92%

Egocentric representations of space co-exist with allocentric representations: Evidence from spatial neglect

Karnath

Rorden

2014

Cortex

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The brain transforms sensory input to motor coordinates to accommodate for changes of posture and gaze direction. Neurophysiological and neuropsychological evidence supports the existence of multiple representations of space. A debated issue regards whether objects that we see are encoded in egocentric frames only or also maintain an object-centered frame of reference. Previous clinical studies were unable to discriminate between these models as the stimuli used to determine object-based (allocentric) biases are contaminated by body-centered (egocentric) effects. To address this, we used stimuli where allocentric side was elicited by gestalt configuration rather than egocentric location. We then displayed these stimuli at different egocentric positions allowing us to independently measure the effects of allocentric position, egocentric position as well as their interaction. In a group of stroke patients with neglect we demonstrate that allocentric biases are modulated as a function of egocentric position. These findings help adjudicate between the different models of space representation, demonstrating that specific allocentric deficits not only exist but also often co-exist with egocentric biases.

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Section: Introductionmentioning

confidence: 92%

Egocentric representations of space co-exist with allocentric representations: Evidence from spatial neglect

Karnath

Rorden

2014

Cortex

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“…In contrast to these reports, Rorden et al (2012), supported by the results of Yue, Song, Huo, and Wang (2012), postulated that allocentric neglect could not be clearly dissociated from egocentric neglect, and that these prior reports of a dissociation were related to the lack of utilization of continuous measures that could capture the severity of both types of deficits.…”

Section: Discussionmentioning

confidence: 57%

Allocentric spatial neglect with posterior cortical atrophy

Zilli

Heilman

2014

Neurocase

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Patients with posterior cortical atrophy (PCA) have been reported to have neglect in the egocentric/ body-centered reference frame. This report describes a woman with PCA who had a right-sided stimulus-based form of allocentric visual neglect on cancellation, reading, and drawing tests. Her brain imaging revealed left parietal atrophy. The pathophysiology of this disorder may be related to an impairment of the ventral "what" stream's ability to interact with the dorsal "where" stream that mediates the allocation of spatial attention, or a deficit in the systems that allocate contralateral focal attention. Further research is needed to better understand the mechanisms of this disorder and to optimally treat it.

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“…Patients such as N.CA. are not in keeping with the idea that allocentric neglect necessarily co-exists with egocentric neglect, as proposed by some authors [10,11]. However, it is probably true that mixed cases (such as C.MC.)…”

Section: Discussionmentioning

confidence: 61%

“…In particular, cases of double dissociation have been reported, with some patients neglecting objects only with respect to egocentric coordinates and other patients neglecting the left side of targets with respect to coordinates centered on the object but independent of the side of space [8,9]. However, it must be added that most patients show mixed forms of egocentric and allocentric neglect [10,11]. Thus, it is important to reliably assess individual performance.…”

Section: Introductionmentioning

confidence: 95%

Italian standardization of the Apples Cancellation Test

et al. 2015

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Hemispatial neglect due to right parieto-temporo-frontal lesions has a negative impact on the success of rehabilitation, resulting in poor functional gain. Recent research has shown that different types of neglect can impact in a different way on rehabilitation outcomes. The availability of a sensitive test, useful for distinguishing egocentric and allocentric forms of neglect, may be clinically important as all current clinical instruments fail to distinguish between these forms of disturbance, yet they differentially predict outcome. The Apples Test is a new instrument useful to evaluate both egocentric and allocentric forms of neglect. In order to establish Italian norms for this diagnostic instrument the test was administered to a sample of 412 healthy people of both genders (201 M and 211 F), aged from 20 to 80 years enrolled from 14 different rehabilitation centers in Italy. Based on the data, we established pathological performance cut-offs for the accuracy score (total omission errors), the asymmetry score for egocentric neglect (omission error difference), the asymmetry score for allocentric neglect (commission error difference) and execution time. The usefulness of the Apples Test for diagnostic purposes is illustrated by presenting three patients with different forms of neglect (egocentric, allocentric and mixed neglect).

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Study on the Occurrence and Neural Bases of Hemispatial Neglect With Different Reference Frames

Cited by 34 publications

References 38 publications

Egocentric representations of space co-exist with allocentric representations: Evidence from spatial neglect

Egocentric representations of space co-exist with allocentric representations: Evidence from spatial neglect

Allocentric spatial neglect with posterior cortical atrophy

Italian standardization of the Apples Cancellation Test

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