Eiji Watanabe Lab @ NIBB, Japan

Upward shadows look darker than downward shadows. * Third award of  the 5th Illusion Contest in Japan . *  Shelf-Shadow Illusion in Visome! Citation; DOI:  https://doi.org/10.6084/m9.figshare.6137558.v1 Eiji Watanabe, Shelf-Shadow Illusion, 2013 Shelf-Shadow Illusion, CG version Shelf-Shadow Illusion, okazaemon version Shelf-Shadow Illusion

In many social fish species, visual cues play an important role in inducing shoaling behavior. The present study is the first to examine whether and how "biological motion" depicting a moving creature by means of only a small number of isolated points induces shoaling behaviour in fish. Medaka (Oryzias latipes ) were used because they are known to have high visual acuity and exhibit a strong tendency to form shoals. In experiment 1, we found that the presentation of medaka biological motion resulted in heightened shoaling behaviour when compared with that of non-biological motion (depicted by a small number of points placed at fixed distances that moved at a constant speed in a constant direction). In experiment 2, it was indicated that medaka biological motion was more effective at inducing shoaling behaviour when compared with human biological motion. In experiment 3, it was demonstrated that shoaling behaviour was largely dependent on the smoothness of the biological mo...