||Hiroshi Ueda, Kentaro Yamamoto, Katsumi Watanabe, Contribution of global and local biological motion information to speed perception and discrimination, Journal of Vision, 10.1167/18.3.2, 18, 3:2, 1-11, 2018.03.
||Yamamoto, K., Miura, K., Effect of motion coherence on time perception relates to perceived speed, Vision Research, 10.1016/j.visres.2015.11.004, 123, 56-62, 2016.06.
||Yamamoto, K., Sasaki, K., Watanabe, K., The number-time interaction depends on relative magnitude in the suprasecond range, Cognitive Processing, 10.1007/s10339-015-0744-3, 17, 1, 59-65, 2016.02.
||Kanji Tanaka, Kentaro Yamamoto, Chien Sung-En, Katsumi Watanabe, Memory distortion of depth of a visual stimulus for perception and action, 2016 8th International Conference on Knowledge and Smart Technology, KST 2016, 10.1109/KST.2016.7440511, 281-286, 2016.03, It has been known remembered locations of visual stimuli are systematically distorted in a two-dimensional (i.e., retinal) coordinate, which includes the foveal bias, memory averaging, and landmark effect. The present study aimed at examining how the remembered depth position of a visual target would be distorted. Also, we examined whether depth distortion would differ for perceptual and motor-related tasks. In the experiments, a visual target was presented for one second at various distances from the observers by using a 3D projector. The fixation distance was also varied. After the disappearance of the target, observers performed either perceptual judgment (the method of constant to estimate the point of psychological subjective equality) or motor response (by using a 3D mouse) for the remembered target distance. The results showed that the remembered depth of the target was compressed toward the averaged depth of the possible depth range for both perceptual and motor responses. In addition, however, the perceptual responses tended to overestimate the depth when the fixation depth was closer than or the same as the nearest possible depth of the target. No bias was observed when the fixation depth was farther than the nearest possible depth. For the motor responses, there was a general underestimation irrespective of fixation depth. These results suggest that spatial memory of depth for visual stimuli may be qualitatively different between perceptual and motor responses..
||Kentaro Yamamoto, Ricky K.C. Au, Katsumi Watanabe, Depth cue combinations for density judgment in three-dimensional display, 2015 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference, APSIPA ASC 2015, 10.1109/APSIPA.2015.7415463, 1198-1202, 2016.02, The present study examined whether different depth cues would interact with the judgment of density differently. Using a 3D projector, we presented random-dot stimuli on fronto-parallel square planes at different depths (-30, -15, 0, +15, or +30 cm from the projection plane) and measured the perceived density of the dots in each depth plane using the method of constant stimuli. The depth of the plane was manipulated with three types of depth cues (binocular disparity, stimulus area, and dot size), which were used separately or all together. The results showed that the averaged PSEs depended on the depth plane when the depth cue was stimulus area, whereas the influences of size and disparity cues on the PSE were relatively weak. However, when the cues were combined, the influence of the area cue on density judgment was largely attenuated. These findings imply that the combination of the depth cues can provide more precise depth perception of the dots and helping interpretations of "3D-valid density"..
||Kentaro Yamamoto, Kanji Tanaka, Katsumi Watanabe, The role of global configuration in detection of mirror and translational symmetries, 2015 - 7th International Conference on Knowledge and Smart Technology, KST 2015, 10.1109/KST.2015.7051479, 165-168, 2015.01, Mirror symmetry is known as a special case of symmetric patterns because of its superior detectability. This study examined whether the perceptual advantage of mirror symmetry is maintained despite the absence of perfect symmetry. We manipulated the alignment of symmetric patterns by adding a vertical offset between left and right halves of them. We found that regularity of mirror symmetry was better detectable than that of translational symmetry in the aligned display. However, the advantage of mirror symmetry disappeared even with the smallest misalignment used in the present study. These results suggest that global configuration of pattern elements plays an important role in mirror symmetry detection..
||Sasaki, K., Yamamoto, K., Miura, K., The difference in speed sequence influences perceived duration, Perception, 10.1068/p7241, 42, 2, 198-207, 2013.02.
||Yamamoto, K., Miura, K., Time dilation caused by static images with implied motion, Experimental Brain Research, 10.1007/s00221-012-3259-5, 223, 2, 311-319, 2012.11.
||Yamamoto, K., Miura, K., Perceived duration of plaid motion increases with pattern speed rather than component speed, Journal of Vision, 10.1167/12.4.1, 12, 4:1, 1-13, 2012.04.
||Kentaro Yamamoto, Fuminori Ono, Yuki Yamada, Kyoshiro Sasaki, Keiko Ihaya, Katsumi Watanabe, Extrinsic motivation underlies precise temporal production, 2011 International Conference on Biometrics and Kansei Engineering, ICBAKE 2011
Proceedings - 2011 International Conference on Biometrics and Kansei Engineering, ICBAKE 2011, 10.1109/ICBAKE.2011.40, 91-94, 2011.10, The present study examined the effect of extrinsic motivation on temporal interval production. Observers were asked to produce the duration of 2.5 sec as accurately as possible, and gained or lost a certain amount of score after each trial. The amount of provided scores varied with the color of target: red or green circle was assigned to high or low scores. We found that the higher amount of expected gain and loss decreased the absolute error of temporal production. However, no effect of motivation was found on the constant error and variable error. These results suggest that extrinsic motivation improved the precision of temporal production. We propose that the striatal dopamine system may mediate motivational influences on time perception..
||Yamamoto, K., Tanaka, S., Kobayashi, H., Kozima, H., Hashiya, K., A Non-Humanoid Robot in the "Uncanny Valley": Experimental Analysis of the Reaction to Behavioral Contingency in 2-3 Year Old Children., PLoS ONE, 4, e6974, 2009.09.