Makin Alexis D J, Chauhan Tushar
Department of Psychological Sciences, University of Liverpool, Liverpool, UK.
J Vis. 2014 Nov 14;14(13):10. doi: 10.1167/14.13.10.
People can estimate the current position of an occluded moving target. This is called motion extrapolation, and it has been suggested that the performance in such tasks is mediated by the smooth-pursuit system. Experiment 1 contrasted a standard position extrapolation task with a novel number extrapolation task. In the position extrapolation task, participants saw a horizontally moving target become occluded, and then responded when they thought the target had reached the end of the occluder. Here the stimuli can be tracked with pursuit eye movements. In the number extrapolation task, participants saw a rapid countdown on the screen that disappeared before reaching zero. Participants responded when they thought the hidden counter would have reached zero. Although this stimulus cannot be tracked with the eyes, performance was comparable on both the tasks. The response times were also found to be correlated. Experiments 2 and 3 extended these findings, using extrapolation through color space as well as number space, while Experiment 4 found modest evidence for similarities between color and number extrapolation. Although more research is certainly needed, we propose that a common rate controller guides extrapolation through physical space and feature space. This functions like the velocity store module of the smooth-pursuit system, but with a broader function than previously envisaged.
人们能够估计被遮挡的移动目标的当前位置。这被称为运动外推，并且有人提出，此类任务中的表现是由平稳跟踪系统介导的。实验1将标准位置外推任务与新颖的数字外推任务进行了对比。在位置外推任务中，参与者看到一个水平移动的目标被遮挡，然后在他们认为目标到达遮挡物末端时做出反应。在这里，刺激可以通过追踪眼动来跟踪。在数字外推任务中，参与者看到屏幕上快速倒计时，在倒计时到零之前消失。参与者在他们认为隐藏的计数器会达到零时做出反应。尽管这个刺激不能通过眼睛来跟踪，但两项任务的表现相当。还发现反应时间是相关的。实验2和3扩展了这些发现，使用了通过颜色空间以及数字空间的外推，而实验4发现了颜色和数字外推之间存在相似性的适度证据。尽管肯定还需要更多研究，但我们提出，一个共同的速率控制器指导通过物理空间和特征空间的外推。这类似于平稳跟踪系统的速度存储模块，但功能比之前设想的更广泛。
