工作记忆表征捕获眼动中的颜色优先性

刺激属性所具有的引导效力在工作记忆表征自上而下地引导注意捕获过程中起重要作用, 已有研究表明工作记忆表征的颜色属性在引导注意时具有一定的优势。研究采用工作记忆任务与视觉搜索任务相结合的双任务范式, 结合眼动追踪技术, 通过设置具有较强引导效力的颜色属性与朝向属性进行直接竞争的实验条件, 进一步考察工作记忆表征的颜色属性是否依然具有优先性。实验1发现工作记忆表征的颜色属性与朝向属性同时竞争眼动捕获时, 颜色属性表现出较强的优势, 而朝向属性单独呈现时并未表现出任何捕获效应。实验2与3进一步证实了颜色属性捕获眼动的优先性, 即当颜色属性在面临作为靶子属性的朝向属性的竞争时, 依然能捕获更多的注视点。这些结果直接证实了工作记忆表征的颜色属性在工作记忆表征的捕获眼动的过程中具有较强的引导效力, 相对于其他刺激属性(如朝向、形状)更具有优先性。

The Priority of Color in Working-Memory-Driven Ocular Capture

The target template maintaining in working memory can guide attention bias to target-like items in the visual scene facilitating the visual search. In addition to the target template, representations in worming memory that are irrelevant to the search target have also been shown to guide attention in a top-down way. During visual search, the distractor sharing attributes with the online working memory representations capture more attention than other distractors, displaying a robust memory-driven attentional capture effect. However, not all stimulus attributes of the working memory representations are equal effective in capturing attention, previous studies showed that the color attribute of a memory-matched distractor was more effective in capturing the first fixation than the shape attribute. According to the opinion of Wolfe and Horowitz (2004), the color attribute was one of the “undoubted guiding attributes” that had greater efficiency for attention guidance than the shape attribute. So it is unclear yet whether color still has such priority when directly competing against the orientation attribute that is also one of the “undoubted guiding attributes”. Three experiments using the classic dual task paradigm were reported here to address this issue. In Experiment 1, participants were asked to search for a specific target accompanied with a distractor which was always located in the opposite visual field of the target. The target and the distractor were respectively embedded in the bar with color and/or orientation attributes same to or different from the objects held in the working memory. The results suggested that the bar would capture more first fixations (i.e. ocular capture effect) only when it shared color attribute with the memory items than when it did not, most importantly, the color-matched bar still captured more first fixations than the orientation-matched bar while they simultaneously appeared and directly competed for attention. In Experiment 2 and 3, participants were required to search either color or orientation of the remembered object. The results showed that in the color search task, ocular capture occurred when the color attributes of the target matched the remembered object regardless of the orientation attribute. However, in the orientation search task, ocular capture still occurred when the distractor was of the same color as the remembered object and slowed down search. These asymmetric results again demonstrated the priority of color attribute in the working memory representation. In conclusion, these results indicate that attentional priority could modulate attentional guidance from working memory, and the color attribute is of greater attentional priority for ocular capture than orientation.