Eiji Watanabe Lab @ NIBB, Japan

We used retro-reflection to perform three-dimensional imaging in water, and applied it to medaka behavior analysis. Erina Abe, Masaki Yasugi, Hideaki Takeuchi, Eiji Watanabe, Yasuhiro Kamei, and Hirotsugu Yamamoto, Development of omnidirectional aerial display with aerial imaging by retro-reflection (AIRR) for behavioral biology experiments. Optical Review https://doi.org/10.1007/s10043-019-00502-w (2019)

Ink blots Illusion Ink blots on the blind curtain expands. Citation; DOI:  https://doi.org/10.6084/m9.figshare.6137582 Eiji Watanabe, Ink blots Illusion, 2018 You can see many variations of Ink blots Illusion at  https://doi.org/10.6084/m9.figshare.6137582 .

Deep neural networks (DNNs), which have been developed with reference to the network structures and the operational algorithms of the brain, have achieved notable success in a broad range of fields, including computer vision, in which they have produced results comparable to, and in some cases superior to, human experts. In recent years, DNNs have also been expected to be useful as a tool for studies of the brain. Recently a research team led by associate professor Eiji Watanabe of the National Institute for Basic Biology successfully reproduced illusory motion by DNNs trained for prediction. The DNNs are based on predictive coding theory (Figure 1), which assumes that the internal models of the brain predict the visual world at all times and that errors between the prediction and the actual sensory input further refine the internal models. If the theory substantially reproduces the visual information processing of the brain, then the DNNs can be expected to represent the human vis...

We have released 3DCG Medaka Fish Creation Manual ! You are free to share it (CC BY 4.0). https://doi.org/10.6084/m9.figshare.5947339

Medaka Fish in Summer and Winter (from NIBB HP) In many areas, the environment fluctuates greatly depending on the season, and animals living in those areas must adapt to the changing environment. A research group from the National Institute for Basic Biology and Nagoya University in Japan found that color perception of Medaka, a small fish inhabiting rice fields and streams, varies greatly according to seasonal changes. Collaborative Research Projects with Yoshimura Laboratory. For details, please refer to NIBB's website . The article “Dynamic plasticity in phototransduction regulates seasonal changes in color perception” was published in Nature Communications. http://dx.doi.org/10.1038/s41467-017-00432-8 Authors: Tsuyoshi Shimmura, Tomoya Nakayama, Ai Shinomiya, Shoji Fukamachi, Masaki Yasugi, Eiji Watanabe, Takayuki Shimo, Takumi Senga, Toshiya Nishimura, Minoru Tanaka, Yasuhiro Kamei, Kiyoshi Naruse, Takashi Yoshimura

We studied social approach behaviour in medaka fish using three-dimensional computer graphic (3DCG) animations based on the morphological features and motion characteristics obtained from real fish. This is the first study which used 3DCG animations and examined the relative effects of morphological and motion cues on social approach behaviour in medaka. Various visual stimuli, e.g., lack of motion, lack of colour, alternation in shape, lack of locomotion, lack of body motion, and normal virtual fish in which all four features (colour, shape, locomotion, and body motion) were reconstructed, were created and presented to fish using a computer display. Medaka fish presented with normal virtual fish spent a long time in proximity to the display, whereas time spent near the display was decreased in other groups when compared with normal virtual medaka group. The results suggested that the naturalness of visual cues contributes to the induction of social approach behaviour. Differential eff...

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...

3D animation of Frohlich effect has been uploaded. http://youtu.be/1vAw8nsCw4w & one more. "the Representational Momentum" http://youtu.be/9eeOfqS1oCI

Visual motion cues are one of the most important factors for eliciting animal behaviour, including predator-prey interactions in aquatic environments. To understand the elements of motion that cause such selective predation behaviour, we used a virtual plankton system where the predation behaviour in response to computer-generated prey was analysed. First, we performed motion analysis of zooplankton ( Daphnia magna ) to extract mathematical functions for biologically relevant motions of prey. Next, virtual prey models were programmed on a computer and presented to medaka ( Oryzias latipes ), which served as predatory fish. Medaka exhibited predation behaviour against several characteristic virtual plankton movements, particularly against a swimming pattern that could be characterised as pink noise motion. Analysing prey-predator interactions via pink noise motion will be an interesting research field in the future. Matsunaga, W. & Watanabe, E. Visual motion with pink noise ...

We have uploaded "Flash-drag Effect: Optical Illusion 3D". The video is available in YouTube (click URL described in the next line). http://youtu.be/H6XOIN4jaDQ Further, a demonstration animation of depth perception has been uploaded. The video is also available in YouTube. http://youtu.be/RdNbBsoQj_I & one more optical illusion (Geared flash-lag effect, 01/06/2012). http://youtu.be/X8RiaNUFIaU

We have generated Flash-lag Effect in 3D space with Blender software. The video is available in YouTube. http://youtu.be/DUBM-GG0gAk

The lady appears to aim her arrow at the space above the star, but she is actually shooting the star. Four variations illustrated by Ms. Nao Tomita, NIBB. Click the illustrations will enlarge images. Refer to following URL (Akiyoshi's illusion pages)! http://www.psy.ritsumei.ac.jp/~akitaoka/friends9e.html

[Motion signals deflect relative positions of moving objects] The perceived relative position of a moving object is frequently shifted as compared to the relative position of the object in the real world.  The illusions have traditionally been explained by temporal models that influence the perceptual latency of visual objects.  However, another compelling theory has recently been proposed on the basis of spatial models that directly influence the coded location of visual objects.  In this study, spatial models were further supported by three different types of illusions composed of apparent motions, in which the perceived relative positions of stationary but apparently moving objects were shifted.  One of three illusions was developed as a novel type of illusion in this paper ( kebab illusion ).  The relative position shift of a stationary object suggested that spatial models play important roles on assignment of position of moving object as well as temporal m...

Which point do the eyes look at? The third point from the top? The 4th one? When the sight line is defined as a line connecting the centers of white eye and black eye,  the eyes look at the top point (see below). This optical illusion can be simplified as below. See Akiyoshi's illusion page! http://www.psy.ritsumei.ac.jp/~akitaoka/friends8e.html Citation: Watanabe illusion 2010, Eiji Watanabe (2010)  https://doi.org/10.6084/m9.figshare.5838606