Malcolm George L, Henderson John M
University of Edinburgh, UK.
J Vis. 2009 Oct 6;9(11):8.1-13. doi: 10.1167/9.11.8.
We can locate an object more quickly in a real-world scene when a specific target template is held in visual working memory, but it is not known exactly how a target template's specificity affects real-world search. In the present study, we compared word and picture cues in real-world scene search. Using an eye-tracker, we segmented search time into three behaviorally defined epochs: search initiation time, scanning time, and verification time. Results from three experiments indicated that target template specificity affects scanning and verification time. Within the scanning epoch, target template specificity affected the number of scene regions visited and the mean fixation duration. Changes to SOA did not affect this pattern of results. Similarly, the pattern of results did not change when participants were familiarized with target images prior to testing, suggesting that an immediately preceding picture provides a more useful search template than one stored in long-term memory. The results suggest that the specificity of the target cue affects both the activation map representing potential target locations and the process that matches a fixated object to an internal representation of the target.
当特定目标模板保存在视觉工作记忆中时，我们能够在现实场景中更快地定位物体，但目前尚不清楚目标模板的特异性如何影响现实世界中的搜索。在本研究中，我们比较了现实场景搜索中的文字和图片线索。使用眼动仪，我们将搜索时间分为三个行为定义的阶段：搜索启动时间、扫描时间和验证时间。三个实验的结果表明，目标模板特异性会影响扫描和验证时间。在扫描阶段，目标模板特异性影响访问的场景区域数量和平均注视持续时间。对刺激呈现间隔（SOA）的改变并未影响这一结果模式。同样，当参与者在测试前熟悉目标图像时，结果模式也没有改变，这表明紧接在前的图片比存储在长期记忆中的图片提供了更有用的搜索模板。结果表明，目标线索的特异性既影响表示潜在目标位置的激活图，也影响将注视物体与目标内部表征进行匹配的过程。
