Authors: Muto, H., Matsushita, S., & Morikawa, K. (武藤拓之・松下戦具・森川和則)

Object’s symmetry alters spatial perspective-taking processes

Journal(書誌情報):Cognition, 191

doi: 10.1016/j.cognition.2019.05.024
Spatial perspective-taking (SPT) refers to one’s ability to identify or understand the location of a target relative to another viewpoint, which could be specified by a human-like agent or a reference object (e.g., a chair). Previous studies have shown that SPT is characterized by different processes depending on whether one is required to make a left/right or front/behind judgment. An object’s shape, however, may also account for the different processes, as previous studies typically used reference objects that were left–right symmetrical and front–back asymmetrical (e.g., human figures, dolls, or chairs), thus confounding effects of judgment direction and effects of objects’ shape. To address this issue, we manipulated objects’ shape (symmetrical or asymmetrical about front–back or left–right) independently of judgment direction (i.e., left/right or front/behind) and compared participants’ efficacy of such judgments. Our results showed that egocentric transformations were used more frequently for judgments orthogonal to the object’s symmetry plane than for judgments orthogonal to the object’s asymmetry plane, whereas the inverse was true for mental scanning. Notably, these tendencies were observed regardless of whether the judgment was about left/right or front/behind. Nonetheless, egocentric transformations were found to be more difficult to apply to the front/behind judgments than to the left/right judgments. We also found that this difficulty was alleviated by rich imagination. Furthermore, we found that participants tended to erroneously perceive a front–back symmetrical human-like object as facing them, even when it was actually facing away from them (facing bias). This in turn forced the participants to conduct unnecessary egocentric transformations. Overall, our findings demonstrated that objects’ symmetry dramatically influenced SPT processes.

著者Contact先の email:
h.muto[at] (武藤拓之)([at] を@に置き換えてください)

自分とは異なる視点に立って物の空間的な位置関係を把握する能力(空間的視点取得)に関する研究です。本研究では,空間的視点取得の認知プロセスがその対象となる物体の形状によって変化することを示しました。具体的には,(1) 物体の形状 (前後左右の対称性) によって2つのプロセス (自己の心的回転と心的走査) のうちどちらが優勢となるのかが変化すること,(2) それぞれのプロセスが特定の物体の形状に最適化されていること,(3) 通常とは異なる状況においても人が柔軟に両プロセスを使い分けられること (およびその一部が想像力に媒介されること),(4) 前後が曖昧な人型の物体を見たときに自動的にその視点を(誤って)取得してしまうこと,などを発見しました。(武藤)