視覚的補完現象におけるアウェアネスとクオリアの心理物理学的検討(2001年度 第2回フォーラム 視覚的アウェアネスとクオリア-心理物理学的手法からどう迫るか)

抄録

In visual amodal completion, we can aware the presence of occluded surfaces in spite of the fact that the surfaces are invisible. By contrast, in the case of modal completion, we can actually perceive the quality of the completed surfaces. We reviewed and compared the psychophysical findings on amodal and modal completion. The studies on the shrinkage phenomenon of the completed surface indicated that the magnitude of the distortion decreases if the occluded part is modally visible. The microgenetic studies revealed that the speed of amodal completion is much slow in comparison with that of modal completion, while both types of completion occur preattentively and automatically. The experiments on local and global factors in figural completion showed that global processes play a major role in amodal completion, while local processes dominate in modal completion. These facts are discussed in relation to the theoretical assumptions that awareness provides flexibility on the output side, while qualia guarantee irrevocability on the input side (Ramachandran, 1998), and that qualia have a function of flagging the present (Gregory, 1998).