The space of senses: impaired crossmodal interactions in a patient with Balint syndrome after bilateral parietal damage

Détails

ID Serval
serval:BIB_37AF71ED94C9
Type
Article: article d'un périodique ou d'un magazine.
Sous-type
Etude de cas (case report): rapporte une observation et la commente brièvement.
Collection
Publications
Institution
Titre
The space of senses: impaired crossmodal interactions in a patient with Balint syndrome after bilateral parietal damage
Périodique
Neuropsychologia
Auteur⸱e⸱s
Valenza  N., Murray  M. M., Ptak  R., Vuilleumier  P.
ISSN
0028-3932
Statut éditorial
Publié
Date de publication
2004
Peer-reviewed
Oui
Volume
42
Numéro
13
Pages
1737-48
Notes
Case Reports
Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Résumé
Balint syndrome after bilateral parietal damage involves a severe disturbance of space representation including impaired oculomotor behaviour, optic ataxia, and simultanagnosia. Binding of object features into a unique spatial representation can also be impaired. We report a patient with bilateral parietal lesions and Balint syndrome, showing severe spatial deficits in several visual tasks predominantly affecting the left hemispace. In particular, we tested whether a loss of spatial representation would affect crossmodal interactions between simultaneous visual and tactile events occurring at the same versus different locations. A tactile discrimination task, where spatially congruent or incongruent visual cues were delivered near the patient's hands, was used. Following stimulation of the left hand in the left side of space, we observed visuo-tactile interactions that were not modulated by spatially congruent conditions. In contrast, performance following stimulation of the right hand in the right side of space was affected in a spatially selective manner--facilitated for congruent stimuli and slowed for incongruent stimuli. To dissociate effects on somatotopic and spatiotopic coordinates, we crossed the patient's hands during unimodal tactile discriminations. Tactile performance of the left hand improved when it was positioned in the right hemispace, whereas placing the right hand in left space produced no significant changes, suggesting that left-sided tactile inputs are coded with respect to a combination of limb- and trunk-centred coordinates. These data converge with recent findings in animals and healthy humans to indicate a critical role of the posterior parietal cortex in multimodal spatial integration, and in the fusion of different coordinates into a unified representation of space.
Mots-clé
Analysis of Variance Ataxia/physiopathology Brain Diseases/*physiopathology Discrimination (Psychology)/physiology Eye Movements/*physiology Female Functional Laterality/physiology Humans Magnetic Resonance Imaging/methods Middle Aged Neuropsychological Tests Parietal Lobe/*injuries/pathology Perceptual Disorders/*physiopathology Photic Stimulation/methods Psychomotor Performance/*physiology Reaction Time/physiology Space Perception/*physiology Syndrome
Pubmed
Web of science
Création de la notice
21/01/2008 10:23
Dernière modification de la notice
20/08/2019 13:26
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