Object Recognition Processes for Motor Output Formation in Visual Agnosic Patients

Funded Activity Summary

Damage to the temporo-occipito-parietal areas of the brain leads to selective impairment in cognitive activities, including motor control and vision. Impaired higher visual processes necessary for object recognition, with intact primary visual functions, is defined as visual agnosia. Experimental work in this disorder has been confined largely to the perceptual aspects, neglecting the functional (motoric) consequences. In a series of kinematic and perceptual experiments, we will require patients with visual agnosia to grasp objects presented in unusual perspectives or variable illumination. The findings will enlarge our knowledge in three ways. First, they will clarify how distributed, but parallel object-recognition processes are coordinated for intended action towards a goal. Little is known about how we adapt our actions to object perception. A tool can be viewed from different angles, or as having different functional uses, but currently we are unable to explain how the mental representation influences the motor output to that tool. By studying a disrupted system, as in visual agnosia, we can speculate about the organisation of the intact system. Second, this project has important implications for new rehabilitative approaches for subjects affected by object recognition disorders. Only if we understand more fully the nature of the poor visuo-motor coordination, can we implement more efficient rehabilitative techniques. Finally, this project will also contribute to the classification of visual agnosia. Although it is commonly agreed that all agnosic patients are different, there is no standard taxonomy for the disorder. An instrument is necessary which represents the basic empirical phenomena, and which provides objective distinctions between different syndromes. Kinematic characterisation of the perceptual and motor control dysfunction in visual agnosia may be the key to open the file of this fascinating yet poorly understood disorder.

Funded Activity Details

Start Date: 01-01-2000

End Date: 01-01-2002

Funding Scheme: NHMRC Project Grants

Funding Amount: $199,260.00

Funder: National Health and Medical Research Council

Research Topics

ANZSRC Field of Research (FoR)

Medical infection agents (incl. prions)

ANZSRC Socio-Economic Objective (SEO)

There are no SEO codes available for this funding activity

Other Keywords

Kinematics of the reach-to-grasp movement | Neuropsychology | Object representations used for motor output formation | Rehabilitation strategies based on functional tasks | Representation used by the brain for encoding 3D objects | Stroke | The relationship between the perceptual and the motor system | Visual agnosia

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