Perception and action in depth
Perception and action in depth
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DOI：
10.1006/ccog.1998.0366
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发表时间：
1998-09-01
影响因子：
2.4
通讯作者：
Milner, AD
中科院分区：
文献类型：
--
作者：
Carey, DP;Dijkerman, HC;Milner, AD
关于后脑损伤患者的距离处理知之甚少。虽然许多研究者声称，在这些患者中，距离估计是正常或异常的，但许多观察都是非正式的，检查者经常要求相对的，而不是绝对的距离估计。本次调查有两个目的。首先，我们想对比视觉形式失认症患者DF在近个人空间中使用距离信息进行感知报告与视觉运动控制的情况。其次，我们想看看她处理距离线索的能力在多大程度上依赖于双眼视觉，根据米尔纳等人的研究。的（1991）的观察保存立体视觉DF，和Dijkerman等人。's（1996）和Marotta等人。（1997）的观察，她的视觉引导抓取可能特别依赖于目标的双眼视觉。我们假设，DF的视觉反应将显示正常的敏感性目标的距离，而她的感知估计不会。在第一个实验中，我们要求DF和两个年龄和性别匹配的控制对象伸出手，抓住放置在不同距离的黑色立方体，或估计立方体的距离，从手的起始位置，而不作出达到运动。在第二个实验中，我们要求DF和两个年龄匹配的控制对象，以尽可能迅速和准确地指向小LED目标，不同的空间位置，在双目和单眼条件下。结果表明，相对于对照组，DF的抓取动作产生正常的峰值速度-距离缩放-当她达到不同深度的块或指向LED目标，这是在不同的深度距离。相比之下，在立方体实验中，她对物体距离的口头估计很差，尽管在双目条件下略有改善。结果进行了讨论，在目前的理论处理流在纹外视皮层和分类和协调空间处理之间的区别。(C)北京：科学出版社.
Little is known about distance processing in patients with posterior brain damage. Although many investigators have claimed that distance estimates are normal or abnormal in some of these patients, many of these observations were made informally and the examiners often asked for relative, and not absolute, distance estimates. The present investigation served two purposes. First, we wanted to contrast the use of distance information in peripersonal space for perceptual report as opposed to visuomotor control in our visual form agnosic patient, DF. Second, we wanted to see to what extent her abilities to process distance cues were dependent on binocular vision, in light of Milner et al.'s (1991) observations of preserved stereopsis in DF, and Dijkerman et al.'s (1996) and Marotta et al.'s (1997) observations that her visual guidance of grasping may be particularly dependent on binocular vision of the target. We hypothesized that DF's visuomotor responses would show normal sensitivity to target distance, while her perceptual estimates would not. In the first experiment, we required DF and two age- and sex-matched control subjects to reach out and grasp black cubes placed at varying distances, or to estimate the distance of the cubes from the hand starting position without making a reaching movement. In the second experiment, we required DF and two age-matched control subjects to point as rapidly and accurately as possible to small LED targets which differed in spatial location, under binocular and monocular conditions. The results showed that, relative to the control subjects, DF's grasping movements produced normal peak velocity-distance scaling-when she reached for blocks which varied in depth or pointed to LED targets which were presented at different distances in depth. In contrast, in the cube experiment, her verbal estimates of object distance were poorly scaled, although they improved slightly under the binocular conditions. The results are discussed in terms of current theories of processing streams in extrastriate visual cortex and the distinction between categorical and coordinate Spatial processing. (C) 1998 Academic Press.