复合字母刺激心理旋转加工中的整体优先效应

采用复合字母材料结合正镜像判断任务，首次揭示了心理旋转加工中的整体优先效应。实验一延长复合字母材料的呈现时间，检验心理旋转实验常用的正/镜像判断任务中的视知觉整体优先效应；实验二将实验一的复合字母材料旋转一定角度，考察心理旋转加工中的整体优先效应。结果发现：（1）延长复合字母呈现时间后的字母正镜像判断任务中，被试判断大字母和判断小字母的时间没有显著差异，并且大小字母是否一致对大字母判断和小字母判断的影响无显著差异；（2）在排除了视知觉的整体优先效应存在的情况下，发现心理旋转加工中存在明显的整体优先效应，大字母（整体）旋转条件下的反应时显著短于小字母（局部）旋转条件下的反应时；（3）旋转角度一致性对大字母旋转和小字母旋转条件下的反应时均无显著影响，表明心理旋转的整体优先效应模式可能有别于视知觉加工的整体优先效应模式

The Effect of Global Precedence on Mental Rotation of Compound Stimuli

Perceptual global precedence referred to a priority in perceptual processing for the global features of a form or object. This phenomenon was firstly reported by Navon (1977) with compound stimuli (larger letters were constructed from smaller letters, e.g., a large H made up of small Ss). Navon required observers to identify either the large (i.e., global) or the small (i.e., local) letters and found that global letters were identified more rapidly than local letters and also that irrelevant global letters were more difficult to ignore than irrelevant local letters. Perceptual global precedence had been widely replicated within certain boundary conditions (Dalrymple et al., 2007; Roalf et al, 2006; Schatz &; Erlandson, 2003; Han Shihui &; Chen Lin, 1996; Kimchi, 1992). However, it was still unclear that whether global precedence could exist in other higher cognitive processes, such as mental rotation. Mental rotation was one typical transformation of mental images, which was reported to be functional equivalence with visual perception. Whether there was an effect of global precedence on mental rotation was explored in the present research. Compound stimuli combined with rotation task were used in two experiments. Participants were required to judge whether the large letter or small letter of the compound stimulus was in its regular format or left-right mirror. In Experiment 1, 2 (task: identification of normal image /mirror-reversed image for large or small letters )×2 (stimuli : congruence or incongruence of large-small letters) was designed to eliminate perceptual global precedence through prolonging the duration of target stimuli. Experiment 2 investigated the global precedence on mental rotation with a 4 (rotation degree: 0°, 60°, 120°, 180°) ×2 (rotation pattern: rotation of large letters or small letters) ×2 (stimuli: congruence or incongruence of rotation angles of large-small letters) within-subject factorial design. Repeated measures analyses of variance were conducted separately for the two experiments. In experiment 1, perceptual global precedence could be eliminated by prolonging targets’ duration. There was no significant difference between the RTs of identification of normal image for large and small letters, and the congruity of large-small letters had no effect on identification of normal image for large and small letters. However, in experiment 2, when mental rotation was added to the task, large letters were responded more quickly than small letters, though the congruity of rotation angles of large-small letters didn’t influence the rotation of large and small letters; in addition, the difference between the rotation speeds of the large letters and small letters reached a marginal significant level. Based on these results, the conclusion was that global precedence did exist in mental rotation even when perceptual global precedence was excluded in mental rotation task. Time required in global rotation was much shorter than that in local rotation. In addition, neither large letters rotation nor small letters rotation was influenced by the congruity of rotation angles of large-small letters. That was to say, the global precedence in mental rotation was of a little difference from the perceptual global precedence. The present findings not only extended the field of mental image, but also shed light on the research of global precedence in higher cognitive processes, and the method of eliminating perceptual global precedence was also of great significance for future research.