Singhal Anthony, Culham Jody C, Chinellato Eris, Goodale Melvyn A
CIHR Group on Action and Perception, Department of Psychology, University of Western Ontario, London, ON, Canada.
J Vis. 2007 May 4;7(5):5.1-12. doi: 10.1167/7.5.5.
Previous kinematic research suggests that visually guided grasping employs an accurate real-time control system in the dorsal stream, whereas delayed grasping relies on less accurate stored information derived by the perceptual system in the ventral stream. We explored these ideas in two experiments combining visually guided and delayed grasping with auditory tasks involving perception-based imagery and semantic memory. In both experiments, participants were cued to grasp three-dimensional objects of varying sizes. During visually guided trials, objects were visible during the interval between the cue and movement onset. During delayed trials, objects were occluded at the time of the cue. In Experiment 1, the second task required participants to listen to object names and vocally respond if the objects were of a particular shape. In Experiment 2, participants studied a paired-associates list prior to testing and then performed cued recall while grasping. The results of these experiments showed that there was reciprocal interference on both tasks, which was consistently greater during delayed grasping. Experiment 2 showed that the introduction of the second task resulted in larger grip apertures during delayed grasping. This supports the idea that delayed grasping involves processing of stored perception-based information that shares resources with cross-modal tasks involving imagery and memory.
先前的运动学研究表明，视觉引导的抓握在背侧通路中采用精确的实时控制系统，而延迟抓握则依赖于腹侧通路中感知系统衍生的不太精确的存储信息。我们在两个实验中探讨了这些观点，这两个实验将视觉引导和延迟抓握与涉及基于感知的意象和语义记忆的听觉任务相结合。在两个实验中，参与者都被提示抓握不同大小的三维物体。在视觉引导试验中，物体在提示和动作开始之间的间隔期间可见。在延迟试验中，物体在提示时被遮挡。在实验1中，第二项任务要求参与者听物体名称，并在物体为特定形状时口头做出反应。在实验2中，参与者在测试前学习一个配对联想列表，然后在抓握时进行线索回忆。这些实验的结果表明，两项任务之间存在相互干扰，在延迟抓握期间这种干扰一直更大。实验2表明，第二项任务的引入导致延迟抓握期间的抓握孔径更大。这支持了这样一种观点，即延迟抓握涉及对基于感知的存储信息的处理，这些信息与涉及意象和记忆的跨模态任务共享资源。
