Eiji Watanabe Lab @ NIBB, Japan

Why Do We See Colors in a Black-and-White Top? — Predictive AI Offers New Clues to a 200-Year-Old Mystery — When a pattern drawn only in black and white is rotated, people sometimes perceive colors that are not actually present. This phenomenon is known as “subjective color” and has been studied for approximately 200 years as one of the remarkable mysteries of vision. Among such phenomena, Benham’s top is a well-known example in which colors are perceived simply by spinning a black-and-white disk. A research group led by Kyohei Ueda, a graduate student at the Laboratory of Neurophysiology, National Institute for Basic Biology, and SOKENDAI; Dr. Lana Sinapayen, a researcher at Sony Computer Science Laboratories Kyoto and concurrently a Specially Appointed Associate Professor at the AI Facility, Center for Trans-Scale Biology, National Institute for Basic Biology; and Associate Professor Eiji Watanabe of the Laboratory of Neurophysiology, National Institute for Basic Biology, who also se...

Preparation of Pseudopregnant Recipient Females Using Female Mice ( Mus musculus ) Showing Nonestrous Signs: Investigation of a Unique Approach Based on the Whitten Effect Abstract Availability of pseudopregnant recipient females is an essential component of embryo transfer in mice. However, conventional methods for sorting females based on estrous signs (proestrus or estrus) require maintaining a large stock of mice, thereby presenting challenges for animal welfare. Furthermore, these large numbers of female mice are often maintained in group housing due to space constraints; and this can induce the Lee-Boot effect, leading to decreased preparation efficiency. Therefore, this study examined a method for preparing pseudopregnant recipient females using mice showing nonestrous signs through a unique approach based on the Whitten effect. Female ICR mice exhibiting metestrus or diestrus characteristics were deliberately sorted and housed with vasectomized males for 3 consecutive days. The...

  Title: Using SlowFast Networks for Near-Miss Incident Analysis in Dashcam Videos Authors: Zhang, Emura, and Watanabe

  The deep echo state network (Deep-ESN) architecture, which comprises a multi-layered reservoir layer, exhibits superior performance compared to conventional echo state networks (ESNs) owing to the divergent layer-specific time-scale responses in the Deep-ESN. Although researchers have attempted to use experimental trial-and-error grid searches and Bayesian optimization methods to adjust the hyperparameters, suitable guidelines for setting hyperparameters to adjust the time scale of the dynamics in each layer from the perspective of dynamical characteristics have not been established. In this context, we hypothesized that evaluating the dependence of the multi-time-scale dynamical response on the leaking rate as a typical hyperparameter of the time scale in each neuron would help to achieve a guideline for optimizing the hyperparameters of the Deep-ESN. Inoue, Nobukawa et al., Frontiers in Artificial Intelligence 2024 https://doi.org/10.3389/frai.2024.1397915

Integration of motion information in illusory motion perceived in stationary patterns https://www.nature.com/articles/s41598-023-48265-4 Illusory motion is a phenomenon in which stationary images with repeating luminance gradient patterns appear to be moving. In this study, we conducted experiments focusing on illusory motion to verify the hypothetical rule that velocity information, extracted from local luminance patterns, is integrated by summation in visual information processing. This rule is based on the hypothesis of velocity integration, and could estimate perceived velocity of stimulus. The summation rule was evaluated by a psychophysical experiment. Our results showed that the summation rule unbiasedly predicted perceived velocity, suggesting that an algorithm for integrating velocity information in illusory motion is based on the summation rule. These results would contribute to understanding of the spatial integration of local motion signals in visual information processing.

Teleost fishes exhibit complex sexual characteristics in response to androgens, such as fin enlargement and courtship display. However, the molecular mechanisms underlying their evolutionary acquisition remain largely unknown. To address this question, we analyse medaka (Oryzias latipes) mutants deficient in teleost-specific androgen receptor ohnologs (ara and arb). We discovered that neither ar ohnolog was required for spermatogenesis, whilst they appear to be functionally redundant for the courtship display in males. However, both were required for reproductive success: ara for tooth enlargement and the reproductive behaviour eliciting female receptivity, arb for male-specific fin morphogenesis and sexual motivation. We further showed that differences between the two ar ohnologs in their transcription, cellular localisation of their encoded proteins, and their downstream genetic programmes could be responsible for the phenotypic diversity between the ara and arb mutants. These findin...