Caddigan Eamon, Lleras Alejandro
Department of Psychology, University of Illinois at Urbana-Champaign, USA.
J Vis. 2010 Dec 6;10(14):9. doi: 10.1167/10.14.9.
Previous studies have shown that even in the context of fairly easy selection tasks, as is the case in a pop-out task, selection of the pop-out stimulus can be sped up (in terms of eye movements) when the target-defining feature repeats across trials. Here, we show that selection of a pop-out target can actually be delayed (in terms of saccadic latencies) and made less accurate (in terms of saccade accuracy) when the target-defining feature has recently been associated with distractor status. This effect was observed even though participants' task was to fixate color oddballs (when present) and simply press a button when their eyes reached the target to advance to the next trial. Importantly, the inter-trial effect was also observed in response time (time to advance to the next trial). In contrast, this response time effect was completely eliminated in a second experiment when eye movements were eliminated from the task. That is, when participants still had to press a button to advance to the next trial when an oddball target was present in the display (an oddball detection task experiment). This pattern of results closely links the "need for selection" in a task to the presence of an inter-trial bias of attention (and eye movements) in pop-out search.
先前的研究表明，即使在相当简单的选择任务中，比如在弹出任务中，当目标定义特征在各次试验中重复出现时，（从眼动角度来看）弹出刺激的选择速度可以加快。在此，我们表明，当目标定义特征最近与干扰项状态相关联时，弹出目标的选择实际上会被延迟（从扫视潜伏期角度来看），并且准确性会降低（从扫视准确性角度来看）。即使参与者的任务是注视颜色异常刺激（如果存在），并且当他们的眼睛到达目标时只需按下按钮以进入下一次试验，这种效应仍然会被观察到。重要的是，在反应时间（进入下一次试验的时间）方面也观察到了这种试验间效应。相比之下，在第二个实验中，当任务中消除了眼动时，这种反应时间效应就完全消除了。也就是说，当显示器中出现异常目标时，参与者仍然必须按下按钮以进入下一次试验（一个异常检测任务实验）。这种结果模式将任务中的“选择需求”与弹出搜索中试验间注意力（和眼动）偏差的存在紧密联系起来。
