Neuroscience Program, University of Western Ontario, London, Canada.
Psychol Sci. 2011 Jun;22(6):803-11. doi: 10.1177/0956797611408733. Epub 2011 May 11.
Much of the current understanding about the capacity limits on the number of objects that can be simultaneously processed comes from studies of visual short-term memory, attention, and numerical cognition. Consistent reports suggest that, despite large variability in the perceptual tasks administered (e.g., object tracking, counting), a limit of three to four visual items can be independently processed in parallel. In the research reported here, we asked whether this limit also extends to the domain of action planning. Using a unique rapid visuomotor task and a novel analysis of reach trajectories, we demonstrated an upper limit to the number of targets that can be simultaneously encoded for action, a capacity limit that also turns out to be no more than three to four. Our findings suggest that conscious perceptual processing and nonconscious movement planning are constrained by a common underlying mechanism limited by the number of items that can be simultaneously represented.
目前关于可以同时处理的物体数量的上限的理解，主要来自于对视觉短期记忆、注意力和数字认知的研究。尽管在实施的感知任务（例如，物体跟踪、计数）上存在很大的可变性，但一致的报告表明，三到四个视觉项目可以独立地并行处理。在本研究中，我们询问了这个限制是否也扩展到了动作规划领域。我们使用了一种独特的快速视觉运动任务和一种新的到达轨迹分析方法，证明了同时编码动作目标的数量存在上限，这个容量限制也不超过三到四个。我们的发现表明，有意识的感知处理和无意识的运动规划受到一个共同的潜在机制的限制，该机制受到同时可以表示的项目数量的限制。
