Researchers

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KODAKA Yasushi
Research associate
Faculty Department of Medicine
Researchmap https://researchmap.jp/KODAKA_YASU

Education and Career

Academic & Professional Experience

  • Apr. 2021 - Today , Kindai University Faculty of Medicine, Physiology Research associate
  • Apr. 1997 - Mar. 2001 , Electrotechnicallaboratory, METI Information Science section senior researcher
  • Apr. 1996 - Mar. 1997 , Electrotechnicallaboratory, METI Information Science section 研究官
  • Apr. 1993 - Mar. 1996 , Primate Research Institute, Kyoto university Neuroscience section trainee
  • Jun. 1988 - Mar. 1993 , Hirosaki University School of Medicine, Physiology Research associate

Research Activities

Research Areas

  • Informatics, Perceptual information processing
  • Life sciences, Animals: biochemistry, physiology, behavioral science
  • Life sciences, Clinical pharmacy
  • Life sciences, Physiology
  • Life sciences, Neuroscience - general

Research Interests

脳内情報処理 視覚 眼球運動 空間位置認知, Visuo-motor control, Attention, Sensory-motor integration

Published Papers

  1. Dynamic arm movements attenuate the perceptual distortion of visual vertical induced during prolonged whole-body tilt.
    Keisuke Tani; Shinji Yamamoto; Yasushi Kodaka; Keisuke Kushiro
    PloS one  16  (4)  , e0250851-, 2021  , Refereed
  2. Effect of dynamic visual motion on perception of postural vertical through the modulation of prior knowledge of gravity.
    Keisuke Tani; Sho Ishimaru; Shinji Yamamoto; Yasushi Kodaka; Keisuke Kushiro
    Neuroscience letters  716  , 134687-134687, 18, Jan. 2020 
  3. Whole-Body Roll Tilt Influences Goal-Directed Upper Limb Movements through the Perceptual Tilt of Egocentric Reference Frame.
    Keisuke Tani; Yoshihide Shiraki; Shinji Yamamoto; Yasushi Kodaka; Keisuke Kushiro
    Frontiers in psychology  9  , 84-84, 2018 

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Books etc

  1. The MIT Encyclopedia of the Cognitve Sciences , 中島秀之 , animal naviation, emotion (animal) , animal naviation, emotion (animal) , 共立出版 , Nov. 2012

Conference Activities & Talks

  1. Intention generation by prospective subliminal process during hand manipulation in the macaque monkey , Akira Murata; Yasushi Kodaka; Kei Mochizuki; Masahiko Inase , Japan Neuroceience society , 2, Aug. 2023

MISC

  1. Dynamic arm movements attenuate the perceptual distortion of visual vertical induced during prolonged whole-body tilt. , Keisuke Tani; Shinji Yamamoto; Yasushi Kodaka; Keisuke Kushiro , PloS one , 16 , 4 , e0250851 , 2021
    Summary:Concurrent body movements have been shown to enhance the accuracy of spatial judgment, but it remains unclear whether they also contribute to perceptual estimates of gravitational space not involving body movements. To address this, we evaluated the effects of static or dynamic arm movements during prolonged whole-body tilt on the subsequent perceptual estimates of visual or postural vertical. In Experiment 1, participants were asked to continuously perform static or dynamic arm movements during prolonged tilt, and we assessed their effects on the prolonged tilt-induced shifts of subjective visual vertical (SVV) at a tilted position (during-tilt session) or near upright (post-tilt session). In Experiment 2, we evaluated how static or dynamic arm movements during prolonged tilt subsequently affected the subjective postural vertical (SPV). In Experiment 1, we observed that the SVV was significantly shifted toward the direction of prolonged tilt in both sessions. The SVV shifts decreased when performing dynamic arm movements in the during-tilt session, but not in the post-tilt session. In Experiment 2, as well as SVV, the SPV was shifted toward the direction of prolonged tilt, but it was not significantly attenuated by the performance of static or dynamic arm movements. The results of the during-tilt session suggest that the central nervous system utilizes additional information generated by dynamic body movements for perceptual estimates of visual vertical.
  2. Effect of dynamic visual motion on perception of postural vertical through the modulation of prior knowledge of gravity. , Keisuke Tani; Sho Ishimaru; Shinji Yamamoto; Yasushi Kodaka; Keisuke Kushiro , Neuroscience letters , 716 , 134687 , 134687 , 18, Jan. 2020
    Summary:To internally estimate gravitational direction and body orientation, the central nervous system considers several sensory inputs from the periphery and prior knowledge of gravity. It is hypothesized that the modulation of visual inputs, supplying indirect information of gravity, affects the prior knowledge established internally by other sensory inputs from vestibular and somatosensory systems, leading to the alteration of perceived body orientation relative to gravity. In order to test the hypothesis, we examined the effect of presenting a visual motion stimulus during a whole-body static tilt on the subsequent evaluation of the perceived postural vertical. Fifteen subjects watched a target moving along the body longitudinal axis directing from head to feet with constant downward acceleration (CA condition) or constant velocity (CV condition), or they did not receive any visual stimulation (NV condition) during the whole-body static tilt. Subsequently, the direction of the subjective postural vertical (SPV) was evaluated. The result showed that the SPV in the CA condition was significantly tilted toward the direction of the preceding tilt compared to that in the NV condition while those in the CV and NV conditions were not significantly different. The present result suggests that dynamic visual motion along body longitudinal axis with downward acceleration can modulate prior knowledge of gravity, and in turn this affects the perception of body verticality.
  3. Whole-Body Roll Tilt Influences Goal-Directed Upper Limb Movements through the Perceptual Tilt of Egocentric Reference Frame. , Keisuke Tani; Yoshihide Shiraki; Shinji Yamamoto; Yasushi Kodaka; Keisuke Kushiro , Frontiers in psychology , 9 , 84 , 84 , 2018
    Summary:In our day-to-day life, we can accurately reach for an object in our gravitational environment without any effort. This can be achieved even when the body is tilted relative to gravity. This is accomplished by the central nervous system (CNS) compensation for gravitational forces and torque acting on the upper limbs, based on the magnitude of body tilt. The present study investigated how performance of upper limb movements was influenced by the alteration of body orientation relative to gravity. We observed the spatial trajectory of the index finger while the upper limb reached for a memorized target with the body tilted in roll plane. Results showed that the terminal location of the fingertip shifted toward the direction of body tilt away from the actual target location. The subsequent experiment examined if the perceived direction of the body longitudinal axis shifted relative to the true direction in roll plane. The results showed that the perceived direction of the body longitudinal axis shifted toward the direction of the body tilt, which correlated with the shift of the terminal location in the first experiment. These results suggest that the dissociation between the egocentric and gravitational coordinates induced by whole-body tilt leads to systematic shifts of the egocentric reference frame for action, which in turn influences the motor performance of goal-directed upper limb movements.

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Research Grants & Projects

  1. 日本学術振興会, 科学研究費助成事業, Prospectiveな情報による把持運動制御のメカニズム , 近畿大学
  2. Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Quantifying the cognitive action space and utilizing it to improve the quality of movements , Kyoto University
  3. Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Assessment of the distortion in cognitive space - aiming at the improvement of motor performance , Kyoto University

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