Abstract
“The illusion of agency” arises when individuals look at own and other’s hand motions alternately from a first person perspective (Takumi Yokosaka, 2014). Here, agency is a kind of cognition whereby people perceive both congruent movement (CM) and incongruent movement (IM) as a united, single, and continuous motion of one’s own hand. The report says apparent motion (AM) perceived between CM and IM. Then, we consider there are two directional AM repeatedly (from own hand toward other’s one and vice versa) and integration between the two occurs. So, to make AM occurrence denser despite, a CM-IM sequence lasts 250ms despite the former 500ms. And to prevent from interaction between the lasting time ratio of CM:IM and the two AM velocity difference, we used 1:1 despite the former 1:2. IM is a recorded movement of a gloved hand. We asked subject to keep his hand close to the IM. We experimented under three conditions below: (#1) CM lasts 125ms and IM does 125ms without black frame, (#2) 83ms black frame inserted after the sequence of 83ms CM and 83ms IM, (#3) after 83ms CM, two split 41ms-black frames were inserted before and after 83ms IM. As a result, the three in four subjects told the recorded movement is observed in each trial under the condition #1 and #3 while hardly did under #2. “The illusion of agency” was relatively observed under all condition. The fact that the CM and IM were not integrated as a single movement under #1 and #3 indicates the illusion was weaker than #2. Supposing the inserted black frame makes the AM slower, the two-AM-velocity difference is dominant. Therefore, the integrated difference yields the polarity of direction towards the other’s hand. This seems to induce own hand’s predicted position closer to the other’s hand unconsciously.
Meeting abstract presented at VSS 2015