Experimental Psychology, Helmholtz Institute, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands.
Exp Brain Res. 2011 Apr;210(1):57-65. doi: 10.1007/s00221-011-2602-6. Epub 2011 Mar 4.
When two target elements are presented in close proximity, the endpoint of a saccade is generally positioned at an intermediate location ('global effect'). Here, we investigated whether the global effect also occurs for eye movements executed to distracting elements. To this end, we adapted the oculomotor capture paradigm such that on a subset of trials, two distractors were presented. When the two distractors were closely aligned, erroneous eye movements were initiated to a location in between the two distractors. Even though to a lesser extent, this effect was also present when the two distractors were presented further apart. In a second experiment, we investigated the global effect for eye movements in the presence of two targets. A strong global effect was observed when two targets were presented closely aligned, while this effect was absent when the targets were further apart. This study shows that there is a global effect when saccades are captured by distractors. This 'capture global' effect is different from the traditional global effect that occurs when two targets are presented because the global effect of capture saccades also occurs for remote elements. The spatial dynamics of this global effect will be explained in terms of the population coding theory.
当两个目标元素近距离呈现时，眼跳的终点通常会位于中间位置（“全局效应”）。在这里，我们研究了在执行分散注意力的元素时，全局效应是否也会发生。为此，我们对眼动捕获范式进行了改编，使得在一部分试验中呈现两个干扰物。当两个干扰物紧密排列时，会错误地向两个干扰物之间的位置发起眼动。即使程度较小，当两个干扰物相距较远时，也会出现这种效应。在第二个实验中，我们研究了在存在两个目标的情况下，眼动的全局效应。当两个目标紧密排列时，观察到强烈的全局效应，而当目标相距较远时，这种效应则不存在。本研究表明，当眼跳被干扰物捕获时，会产生全局效应。这种“捕获全局”效应与当呈现两个目标时发生的传统全局效应不同，因为捕获眼跳的全局效应也会出现在远程元素中。该全局效应的空间动态将根据群体编码理论进行解释。
