Topographical disorientation

Farrell, Martin J.

doi:10.1080/13554799608402427

Cited by 51 publications

(25 citation statements)

References 53 publications

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“…There is some indication that rapid responses of this nature may be controlled by a relatively short-lived spatial representation that is specialized for the visual control of action within an egocentric frame of reference (Day & Lyon, 2000;Desmurget et al, 1999;Milner & Goodale, 1995;Pisella et al, 2000; see also Aguirre &D'Esposito, 1999, andFarrell, 1996). In this view, a more long-lived representation, presumably subserved by cortical regions lying outside the PPC, controls nonballistic or delayed responses.…”

Section: Discussionmentioning

confidence: 99%

Updating of locations during whole-body rotations in patients with hemispatial neglect

Philbeck

Behrmann

Loomis

2001

Cognitive, Affective, & Behavioral Neuroscience

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Posterior parietal cortex lesions have been associated with both hemispatial neglect and spatialupdating deficits. Currently, the relation between these processes remains poorly understood. We tested the ability of parietal patients with neglect to update remembered target locations during passive whole-body rotations. The rotations and manual pointing responses were executed with and without vision. During the rotation, the remembered location stayed on the same side of the body midline or crossed the midline. Parietal patients generally underestimated rotations, as compared with control groups, but updated targets equally well on either side of the body midline, regardless of the amount of updating required. Once parietal patients have localized a target, they can use self-motion information to update its location, even if it passes into the region they typically neglect. This lack of contralesional updating effects contrasts with impairments in eye position updating found in previous work with parietal patients.

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Section: Discussionmentioning

confidence: 99%

Updating of locations during whole-body rotations in patients with hemispatial neglect

Philbeck

Behrmann

Loomis

2001

Cognitive, Affective, & Behavioral Neuroscience

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“…The taxonomy provided above makes different predictions from those in which a single cortical area is proposed to represent landmark position and identity (47). One such prediction of the divisional model is that a ventral area specialized for representation of environmental features will be recruited to a lesser extent during judgments regarding the position of places compared with periods in which the appearance of places is considered.…”

Section: Neocortical Representations Of Environmental Spacementioning

confidence: 95%

“…Other authors have argued against the existence of such a cognitive (8) or anatomical (46) division. Instead, a unitary representation of both the identity and allocentric location of environmental features has been proposed to exist in a ventral cortical area (47).…”

Section: Neocortical Representations Of Environmental Spacementioning

confidence: 99%

Neural components of topographical representation

Aguirre

Zarahn

D’Esposito

1998

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

146

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Studies of patients with focal brain damage suggest that topographical representation is subserved by dissociable neural subcomponents. This article offers a condensed review of the literature of ''topographical disorientation'' and describes several functional MRI studies designed to test hypotheses generated by that review. Three hypotheses are considered: (i) The parahippocampal cortex is critically involved in the acquisition of exocentric spatial information in humans; (ii) separable, posterior, dorsal, and ventral cortical regions subserve the perception and long term representation of position and identity, respectively, of landmarks; and (iii) there is a distinct area of the ventral occipitotemporal cortex that responds maximally to building stimuli and may play a role in the perception of salient landmarks. We conclude with a discussion of the inferential limitations of neuroimaging and lesion studies. It is proposed that combining these two approaches allows for inferences regarding the computational involvement of a neuroanatomical substrate in a given cognitive process although neither method can strictly support this conclusion alone.The topographical domain may be defined as that space that is beyond our immediate perceptual horizon. Topographical spaces include the interior of a building or the town in which the building is located. We routinely generate internal representations of these spaces, as well as their contents, which suffice to guide us from place to place. There are, perhaps, as many different kinds of representations as there are possible solutions to the problem of way-finding, ranging from inflexible, route-based lists of right and left turns to map-like representations that encode the metric distance relationships between landmarks (1). These representations can be cast within different spatial frames, including egocentric (bodycentered) and exocentric (world-centered) coordinates (2). There is evidence that these different types of representations can be brought to bear in combination and in isolation, depending on the features of the environment (3) and the means (4) and goals (5) of exploration. The aim of this article is to review some recent studies regarding the neural basis of these types of topographical representations.There are three primary ideas that will be presented here. All three fall under the more general proposal that distinct functional, neuroanatomical components, which normally operate in concert to provide the seamless percept of orientation, differentially contribute to the representational processes mentioned above. Each of these hypotheses are related to the performance deficits from which topographically disoriented brain-damaged patients suffer, and these hypotheses have been tested explicitly in intact subjects by using functional magnetic resonance imaging (fMRI).The first hypothesis is that the medial-temporal lobes are regionally subspecialized for the acquisition of topographic information. The hippocampus holds a privileged position (1) in ...

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“…Patients with lesions to posterior parietal, temporal and occipital regions have difficulty in wayfinding (Farrell, 1996), reduced scores on tests of spatial intelligence (Warrington et al, 1986), and impaired performance on laboratory tasks requiring spatial transformations (De Renzi, 1982). The literature also hints at a dissociation between object-based transformations and egocentric perspective transformations, though indirectly.…”

Section: Introductionmentioning

confidence: 99%