Object Recognition Processes for Motor Output Formation in Visual Agnosic Patients

大脑颞枕顶叶区域的损伤导致认知活动的选择性损伤，包括运动控制和视觉。物体识别所必需的高级视觉过程受损，初级视觉功能完好，被定义为视觉失认症。这种疾病的实验工作主要局限于感知方面，而忽略了功能（运动）后果。在一系列的运动学和知觉实验中，我们将要求视觉失认症患者掌握在不同角度或不同光照下呈现的物体。这些发现将从三个方面扩大我们的知识。首先，它们将阐明分布式但并行的对象识别过程是如何为实现目标的预期行动而协调的。我们是如何使自己的行为适应对物体的感知的，我们所知甚少。一个工具可以从不同的角度看待，或者具有不同的功能用途，但目前我们无法解释心理表征如何影响该工具的运动输出。通过研究一个被破坏的系统，比如视觉失认症，我们可以推测完整系统的组织结构。其次，该项目对受物体识别障碍影响的受试者的新康复方法具有重要意义。只有我们更充分地了解视觉运动协调不良的本质，我们才能实施更有效的康复技术。最后，本项目也将有助于视觉失认症的分类。虽然人们普遍认为所有的失认症患者都是不同的，但这种疾病并没有标准的分类。一种工具是必要的，它代表基本的经验现象，并提供不同证候之间的客观区别。视觉失认症中知觉和运动控制功能障碍的运动学特征可能是打开这个迷人但知之甚少的疾病档案的关键。

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.