Shirama Aya, Ishiguchi Akira
Graduate School of Humanities and Sciences, Department of Psychology, Ochanomizu University, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
Shinrigaku Kenkyu. 2009 Jun;80(2):114-22. doi: 10.4992/jjpsy.80.114.
Does amodal completion occur homogeneously across the visual field? Rensink and Enns (1998) found that visual search for efficiently-detected fragments became inefficient when observers perceived the fragments as a partially-occluded version of a distractor due to a rapid completion process. We examined the effect of target eccentricity in Rensink and Enns's tasks and a few additional tasks by magnifying the stimuli in the peripheral visual field to compensate for the loss of spatial resolution (M-scaling; Rovamo & Virsu, 1979). We found that amodal completion disrupted the efficient search for the salient fragments (i.e., target) even when the target was presented at high eccentricity (within 17 deg). In addition, the configuration effect of the fragments, which produced amodal completion, increased with eccentricity while the same target was detected efficiently at the lowest eccentricity. This eccentricity effect is different from a previously-reported eccentricity effect where M-scaling was effective (Carrasco & Frieder, 1997). These findings indicate that the visual system has a basis for rapid completion across the visual field, but the stimulus representations constructed through amodal completion have eccentricity-dependent properties.
无模态完成在整个视野中是否均匀发生？伦辛克和恩斯（1998年）发现，当观察者由于快速完成过程而将碎片视为干扰物的部分遮挡版本时，对易于检测的碎片进行视觉搜索就会变得低效。我们通过放大周边视野中的刺激来补偿空间分辨率的损失（M缩放；罗瓦莫和维尔苏，1979年），研究了目标偏心度在伦辛克和恩斯任务以及其他一些任务中的影响。我们发现，即使目标呈现于高偏心度（17度以内）时，无模态完成也会干扰对显著碎片（即目标）的高效搜索。此外，产生无模态完成的碎片的构型效应随偏心度增加，而相同目标在最低偏心度时能被高效检测。这种偏心度效应不同于之前报道的M缩放有效的偏心度效应（卡拉斯科和弗里德，1997年）。这些发现表明，视觉系统具有在整个视野中快速完成的基础，但通过无模态完成构建的刺激表征具有偏心度依赖的特性。
