School of Psychology, University of Sydney.
J Exp Psychol Gen. 2017 Oct;146(10):1420-1437. doi: 10.1037/xge0000357. Epub 2017 Sep 11.
Capacity limits hinder processing of multiple stimuli, contributing to poorer performance for identifying two briefly presented letters than for identifying a single letter. Higher accuracy is typically found for identifying the letter on the left, which has been attributed to a right-hemisphere dominance for selective attention. Here, we use rapid serial visual presentation (RSVP) of letters in two locations at once. The letters to be identified are simultaneous and cued by rings. In the first experiment, we manipulated implied reading direction by rotating or mirror-reversing the letters to face to the left rather than to the right. The left-side performance advantage was eliminated. In the second experiment, letters were positioned above and below fixation, oriented such that they appeared to face downward (90° clockwise rotation) or upward (90° counterclockwise rotation). Again consistent with an effect of implied reading direction, performance was better for the top position in the downward condition, but not in the upward condition. In both experiments, mixture modeling of participants' report errors revealed that attentional sampling from the two locations was approximately simultaneous, ruling out the theory that the letter on one side was processed first, followed by a shift of attention to sample the other letter. Thus, the orientation of the letters apparently controls not when the letters are sampled from the scene, but rather the dynamics of a subsequent process, such as tokenization or memory consolidation. Implied reading direction appears to determine the letter prioritized at a high-level processing bottleneck. (PsycINFO Database Record
能力限制阻碍了对多个刺激的处理，导致识别两个短暂呈现的字母比识别单个字母的表现更差。通常情况下，识别左边字母的准确性更高，这归因于右半球对选择性注意的主导作用。在这里，我们同时在两个位置使用快速连续视觉呈现（RSVP）呈现字母。要识别的字母同时出现，并通过环提示。在第一个实验中，我们通过旋转或反转字母来改变隐含的阅读方向，使字母面向左侧而不是右侧。左侧的表现优势消失了。在第二个实验中，字母位于注视点上方和下方，方向使它们看起来向下（顺时针旋转 90°）或向上（逆时针旋转 90°）。同样与隐含阅读方向的影响一致，在向下条件下，顶部位置的表现更好，但在向上条件下则不然。在两个实验中，参与者报告错误的混合模型表明，来自两个位置的注意力抽样大致是同时的，排除了一个侧的字母先被处理，然后注意力转移到另一个字母的抽样的理论。因此，字母的方向显然不是控制从场景中抽样字母的时间，而是控制随后过程的动态，例如标记或记忆巩固。隐含的阅读方向似乎决定了在高级处理瓶颈中优先处理的字母。
