Goodale M A, Milner A D, Jakobson L S, Carey D P
Department of Psychology, University of Western Ontario, London, Canada.
Nature. 1991 Jan 10;349(6305):154-6. doi: 10.1038/349154a0.
Studies of the visual capacity of neurological patients have provided evidence for a dissociation between the perceptual report of a visual stimulus and the ability to direct spatially accurate movements toward that stimulus. Some patients with damage to the parietal lobe, for example, are unable to reach accurately towards visual targets that they unequivocally report seeing. Conversely, some patients with extensive damage to primary visual cortex can make accurate pointing movements or saccades toward a stimulus presented in their 'blind' scotoma. But in investigations of visuomotor control in patients with visual disorders, little consideration has been given to complex acts such as manual prehension. Grasping a three-dimensional object requires knowledge not only of the object's spatial location, but also of its form, orientation and size. We have examined a patient with a profound disorder in the perception of such object qualities. Our quantitative analyses demonstrate strikingly accurate guidance of hand and finger movements directed at the very objects whose qualities she fails to perceive. These data suggest that the neural substrates for the visual perception of object qualities such as shape, orientation and size are distinct from those underlying the use of those qualities in the control of manual skills.
对神经疾病患者视觉能力的研究为视觉刺激的感知报告与向该刺激做出空间精确运动的能力之间的分离提供了证据。例如，一些顶叶受损的患者无法准确地朝着他们明确报告看到的视觉目标伸手。相反，一些初级视觉皮层广泛受损的患者能够朝着出现在他们“盲”点的刺激做出准确的指向运动或扫视。但是在对视觉障碍患者的视觉运动控制的研究中，很少有人考虑诸如手动抓握等复杂行为。抓取一个三维物体不仅需要了解物体的空间位置，还需要了解其形状、方向和大小。我们研究了一位在感知此类物体特征方面存在严重障碍的患者。我们的定量分析表明，她的手和手指运动能够非常精确地指向那些她无法感知其特征的物体。这些数据表明，用于视觉感知物体特征（如形状、方向和大小）的神经基质与在控制手动技能时使用这些特征的神经基质是不同的。
