Nissens Tom, Fiehler Katja
Experimental Psychology, Justus Liebig University Giessen, Otto-Behaghel-Strasse 10F, 35394, Giessen, Germany.
Atten Percept Psychophys. 2020 Jul;82(5):2502-2515. doi: 10.3758/s13414-020-01984-6.
Previous studies in visual attention and oculomotor research showed that a physically salient distractor does not always capture attention or the eyes. Under certain top-down task sets, a salient distractor can be actively suppressed, avoiding capture. Even though previous studies showed that reaching movements are also influenced by salient distractors, it is unclear if and how a mechanism of active suppression of distractors would affect reaching movements. Active suppression might also explain why some studies find reaching movements to curve towards a distractor, while others find reaching movements to curve away. In this study, we varied the top-down task set in two separate experiments by manipulating the certainty about the target location. Participants had to reach for a diamond present among three circles. In Experiments 1 and 3, participants had to search for the reach targets; hence, the target's location certainty was low. In Experiments 2 and 3, the target's location was cued before the reach; hence, the target's location certainty was high. We found that reaches curved towards the physically salient, color singleton, distractor in the search-to-reach task (Experiments 1 and 3), but not in the cued reach task (Experiments 2 and 3). Thus, the saliency of the distractor only attracted reaching movements when the certainty of the target's location was low. Our findings suggest that the attractiveness of physically salient distractors to reaching movements depends on the top-down task set. The results can be explained by the effect of active attentional suppression on the competition between movement plans.
以往在视觉注意力和眼动研究方面的研究表明，一个在物理上显著的干扰物并不总是能吸引注意力或眼球。在某些自上而下的任务设置下，一个显著的干扰物可以被主动抑制，从而避免被捕捉。尽管以往的研究表明伸手动作也会受到显著干扰物的影响，但目前尚不清楚干扰物的主动抑制机制是否以及如何影响伸手动作。主动抑制也可能解释了为什么一些研究发现伸手动作会向干扰物弯曲，而另一些研究则发现伸手动作会向远离干扰物的方向弯曲。在本研究中，我们在两个独立的实验中通过操纵目标位置的确定性来改变自上而下的任务设置。参与者必须伸手去拿三个圆圈中出现的一个菱形。在实验1和实验3中，参与者必须搜索伸手目标；因此，目标位置的确定性较低。在实验2和实验3中，在伸手之前提示目标的位置；因此，目标位置的确定性较高。我们发现，在搜索到伸手任务（实验1和实验3）中，伸手动作会向物理上显著的、颜色独特的干扰物弯曲，但在提示伸手任务（实验2和实验3）中则不会。因此，只有当目标位置的确定性较低时，干扰物的显著性才会吸引伸手动作。我们的研究结果表明，物理上显著的干扰物对伸手动作的吸引力取决于自上而下的任务设置。这些结果可以通过主动注意力抑制对运动计划之间竞争的影响来解释。
