Cant Jonathan S, Westwood David A, Valyear Kenneth F, Goodale Melvyn A
CIHR Group on Action and Perception, Department of Psychology, University of Western Ontario, London, Ontario, Canada N6A 5C2.
Neuropsychologia. 2005;43(2):216-26. doi: 10.1016/j.neuropsychologia.2004.11.008. Epub 2005 Jan 7.
Craighero et al. showed that grasping movements were initiated more quickly when the goal object shared the same orientation as a previously seen 'prime' object. Because the goal object was never visible in these experiments, however, it is unclear whether the data should be construed as evidence for a general visuomotor priming effect (as the authors contend), or only as evidence for a more specific priming effect on memory-guided actions. In Experiment 1, we demonstrated that memory-guided but not visually guided grasping can be primed by passive viewing of a prime object. In Experiment 2, we compared the effects of a prime object on the grasping and naming of a visible target object. Participants were faster to name the target when its shape was the same as the prime, consistent with well-established perceptual priming effects. Under the identical set of testing parameters, however, reaction time for grasping was unaffected by the orientation or the shape of the prime. In Experiment 3, participants grasped the goal object after either viewing or grasping a prime object. Reaction time for grasping was unaffected by the visual features of the prime in both tasks. Taken together, these results are consistent with the view that perceptual memory -- which presumably underlies visual priming effects -- is largely irrelevant for programming the metrics of actions to visible objects. Visually guided actions are programmed in real-time by dedicated visuomotor modules that appear to be insensitive to the priming effects that are a hallmark of visual perception.
克莱杰罗等人发现,当目标物体与之前看到的“启动”物体具有相同方向时,抓握动作启动得更快。然而,由于在这些实验中目标物体从未可见,所以尚不清楚这些数据应被解释为一般视觉运动启动效应的证据(如作者所主张的),还是仅作为对记忆引导动作的更具体启动效应的证据。在实验1中,我们证明了被动观看一个启动物体可以启动记忆引导而非视觉引导的抓握。在实验2中,我们比较了启动物体对可见目标物体抓握和命名的影响。当目标形状与启动物体相同时,参与者命名目标的速度更快,这与已确立的知觉启动效应一致。然而,在相同的测试参数集下,抓握的反应时间不受启动物体方向或形状的影响。在实验3中,参与者在观看或抓握一个启动物体后抓握目标物体。在这两个任务中,抓握的反应时间均不受启动物体视觉特征的影响。综合来看,这些结果与以下观点一致:知觉记忆——大概是视觉启动效应的基础——在很大程度上与为可见物体的动作指标编程无关。视觉引导的动作由专门的视觉运动模块实时编程,这些模块似乎对作为视觉感知标志的启动效应不敏感。