Object Recognition Processes for Motor Output Formation in Visual Agnosic Patients

对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。视觉失认症的定义是：视觉失认症是指初级视觉功能完好，但物体识别所必需的高级视觉过程受损。对这种疾病的实验研究主要局限于知觉方面，忽视了功能（运动）方面的结果。在一系列运动学和知觉实验中，我们将要求视觉失认症患者抓住在不寻常的角度或可变照明下呈现的物体。这些发现将从三个方面扩大我们的知识。首先，他们将阐明如何分布式，但并行的对象识别过程是协调的预期行动，以实现一个目标。我们对自己的行为如何适应物体感知知之甚少。一个工具可以从不同的角度来看，或者有不同的功能用途，但目前我们无法解释心理表征如何影响对该工具的运动输出。通过研究一个被破坏的系统，如视觉失认症，我们可以推测完整系统的组织。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-运动协调性差的本质，我们才能实施更有效的康复技术。最后，本研究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，但这种疾病没有标准的分类。需要一种工具来代表基本的经验现象，并提供不同症状之间的客观区别。视觉失认症的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文件的关键。

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.