注意捕获效应受知觉负载及目标与干扰项距离的共同影响

研究考察了无关干扰项引发的注意捕获效应如何受到任务知觉负载以及目标与干扰项距离的共同影响。被试在视觉搜索集中搜索目标并做辨别反应。通过控制搜索集的大小来控制任务知觉负载, 同时在搜索集中存在一个用颜色标定的无关干扰项(奇异项), 该奇异项与当前的搜索目标存在一致、中性或不一致的关系, 该奇异项的位置与当前目标相邻或相距较远。结果发现, 被试在低负载条件下出现显著的干扰效应(不一致条件的反应时减中性条件的反应时), 而在高负载条件下干扰效应减小。此外, 在高负载条件下, 当目标与干扰项相距较近时没有出现干扰效应, 而当目标与干扰项相距较远时存在显著的干扰效应。干扰效应受到任务知觉负载和目标与无关干扰项距离的共同影响。这些结果说明, 与任务无关的刺激是否捕获注意取决于当前任务总体上是否存在可用的剩余注意资源, 也受到其周围临近区域的局部注意资源是否充足的影响。

The Interaction between Perceptual Load and the Target-Distractor Distance in Regulating Stimulus-Driven Attentional Capture

The current study investigated the interaction between the perceptual load in searching for a target and the distance between the target and a task-irrelevant singleton in regulating stimulus-driven attentional capture. Participants were asked to search for a target letter among nontarget letters and were instructed to ignore a differently colored task-irrelevant singleton letter, which was compatible, neutral or incompatible with the response to the target letter. The perceptual load of the search display was low (with set size of 4), medium (with set size of 8) or high (with set size of 12). The target and the task-irrelevant singleton were close to or distant from each other. Results showed that the flanker interference effect, in terms of the reaction times (RTs) in neutral condition subtracted from that in incompatible condition, was significant for the low perceptual load condition, but was reduced for the medium and the high load conditions. Moreover, for the medium and the high load conditions, the flanker effect was significantly larger when the target and the task-irrelevant singleton were distant from each other than when they were close to each other. The flanker effect thus was affected by both the perceptual load of the search display and the distance between the target and the task-irrelevant singleton. These results indicate that whether the task-irrelevant singleton captures attention and causes interference with the current target processing is not only affected by whether there are overall spare attentional resources left from processing the current task, but is also affected by whether there are spare attentional resources at the subregion where the singleton is located.