Performance information

• Top-down effects on translucency perception in relation to shape cues　　　　　　　　　　　　　　　
  Takehiro Nagai; Hiroaki Kiyokawa; Juno Kim
  PLOS ONE, Volume：20, Number：2, Feb. 2025, [Reviewed]
  English, Scientific journal
  DOI：https://doi.org/10.1371/journal.pone.0314439
  DOI ID：10.1371/journal.pone.0314439, ISSN：1932-6203, Web of Science ID：WOS:001425429000021
• Commonalities and variations in emotion representation across modalities and brain regions.　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa; Ryusuke Hayashi
  Scientific reports, Volume：14, Number：1, First page：20992, Last page：20992, Sep. 2024, [Reviewed], [Lead], ［International magazine］
  Humans express emotions through various modalities such as facial expressions and natural language. However, the relationships between emotions expressed through different modalities and their correlations with neural activities remain uncertain. Here, we aimed to unveil some of these uncertainties by investigating the similarity of emotion representations across modalities and brain regions. First, we represented various emotion categories as multi-dimensional vectors derived from visual (face), linguistic, and visio-linguistic data, and used representational similarity analysis to compare these modalities. Second, we examined the linear transferability of emotion representation from other modalities to the visual modality. Third, we compared the representational structure derived in the first step with those from brain activities across 360 regions. Our findings revealed that emotion representations share commonalities across modalities with modality-type dependent variations, and they can be linearly mapped from other modalities to the visual modality. Additionally, emotion representations in uni-modalities showed relatively higher similarity with specific brain regions, while multi-modal emotion representation was most similar to representations across the entire brain region. These findings suggest that emotional experiences are represented differently across various brain regions with varying degrees of similarity to different modality types, and that they may be multi-modally conveyable in visual and linguistic domains.
  English, Scientific journal
  DOI：https://doi.org/10.1038/s41598-024-71690-y
  DOI ID：10.1038/s41598-024-71690-y, PubMed ID：39251743, PubMed Central ID：PMC11385795
• The perception of translucency from surface gloss.　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa; Takehiro Nagai; Yasuki Yamauchi; Juno Kim
  Vision research, Volume：205, First page：108140, Last page：108140, Apr. 2023, [Reviewed], [Lead], ［International magazine］
  English, Scientific journal
  DOI：https://doi.org/10.1016/j.visres.2022.108140
  DOI ID：10.1016/j.visres.2022.108140, ISSN：0042-6989, eISSN：1878-5646, PubMed ID：36336645, Web of Science ID：WOS:000954904300001
• Effects of specular roughness on the perception of color and opacity.　　　　　　　　　　　　　　　
  Yuyang Cai; Hiroaki Kiyokawa; Takehiro Nagai; Leyla Haghzare; Matthew Arnison; Juno Kim
  Journal of the Optical Society of America. A, Optics, image science, and vision, Volume：40, Number：3, First page：A220-A229, Mar. 2023, [Reviewed], ［International magazine］
  Previous studies have shown that information concerning object shape is important for the perception of translucency. This study aims to explore how the perception of semi-opaque objects is influenced by surface gloss. We varied specular roughness, specular amplitude, and the simulated direction of a light source used to illuminate a globally convex bumpy object. We found that perceived lightness and roughness increased as specular roughness was increased. Declines in perceived saturation were observed but were far smaller in magnitude with these increases in specular roughness. There were inverse correlations found between perceived gloss and perceived lightness, perceived transmittance and perceived saturation, and between perceived roughness and perceived gloss. Positive correlations were found between perceived transmittance and glossiness, and between perceived roughness and perceived lightness. These findings suggest that specular reflections influence the perception of transmittance and color attributes, and not just perceived gloss. We also performed follow-up modeling of image data to find that perceived saturation and lightness could be explained by the reliance on different image regions with greater chroma and lower lightness, respectively. We also found systematic effects of lighting direction on perceived transmittance that indicate there are complex perceptual interactions that require further consideration.
  English, Scientific journal
  DOI：https://doi.org/10.1364/JOSAA.479972
  DOI ID：10.1364/JOSAA.479972, PubMed ID：37133045
• Spatial Frequency Effective for Increasing Perceived Glossiness by Contrast Enhancement.　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa; Tomonori Tashiro; Yasuki Yamauchi; Takehiro Nagai
  Frontiers in psychology, Volume：12, First page：625135, Last page：625135, Feb. 2021, [Reviewed], [Lead], ［International magazine］
  English, Scientific journal
  DOI：https://doi.org/10.3389/fpsyg.2021.625135
  DOI ID：10.3389/fpsyg.2021.625135, ISSN：1664-1078, PubMed ID：33613400, PubMed Central ID：PMC7892470, Web of Science ID：WOS:000619274000001
• Luminance edge is a cue for glossiness perception based on low-luminance specular components　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa; Tomonori Tashiro; Yasuki Yamauchi; Takehiro Nagai
  JOURNAL OF VISION, Volume：19, Number：12, Oct. 2019, [Reviewed], [Lead]
  English, Scientific journal
  DOI：https://doi.org/10.1167/19.12.5
  DOI ID：10.1167/19.12.5, ISSN：1534-7362, Web of Science ID：WOS:000492307500005
• Task-relevant Perceptual Learning for Judgments of Visual Material Features　　　　　　　　　　　　　　　
  KIYOKAWA Hiroaki; KAWASHIMA Yuki; YAMAUCHI Yasuki; NAGAI Takehiro
  Transactions of Japan Society of Kansei Engineering, Volume：17, Number：2, First page：309, Last page：319, Apr. 2018, [Reviewed], [Lead]
  There have been growing interests in clarifying perceptual mechanisms for different material features such as glossiness and transparency in recent years. In this study, we examined whether perceptual learning effects can be observed for material perceptions, and whether active conduct of material judgment tasks is important for the learning effects. The observers were divided into two groups; the glossiness group and the transparency group. The former observers repeated a glossiness discrimination task, while the latter observers repeated a transparency discrimination task for 10 days. We measured changes in correct response ratios and reaction times for discriminations of learned and unlearned material features between before and after the learning. In the results, in both learning groups, the reaction times for the learned material features were significantly shortened after the learning. These results suggest that the human visual system can increase glossiness and transparency discrimination performances by actively repeating material discrimination tasks.
  Japan Society of Kansei Engineering, English
  DOI：https://doi.org/10.5057/jjske.tjske-d-18-00019
  DOI ID：10.5057/jjske.tjske-d-18-00019, eISSN：1884-5258, CiNii Articles ID：130006728097

• Skewness adaptation induced an asymmetric effect in glossiness perception but not in translucency.　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa; Keigo Yoshida; Ichiro Kuriki
  Journal of Vision, Volume：24, First page：526, Last page：526, Oct. 2024, [Reviewed]
  English
• Manipulation of glossiness perception by contrast enhancement of high spatial frequency components　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa; Tomonori Tashiro; Yasuki Yamauchi; Takehiro Nagai
  Journal of Vision, Volume：20, First page：364, Last page：364, Jun. 2020, [Reviewed]
  English
• Perceived Glossiness Based on Low-Luminance Specular Components Can Be Increased by Enhancing Luminance Edge Contrasts　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa; Tomonori Tashiro; Yasuki Yamauchi; Takehiro Nagai
  I-PERCEPTION, Volume：10, First page：160, Last page：160, Sep. 2019, [Reviewed]
  English
• Image cues for glossiness perception obtained from low luminance specular reflection components.　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa; Tomonori Tashiro; Yasuki Yamauchi; Takehiro Nagai
  Perception, Volume：48, First page：143, Last page：143, Aug. 2018, [Reviewed]
  English
• Glossiness perception not depending on specular highlights -impacts of luminance edges-　　　　　　　　　　　　　　　
  Hiroaki Kiyokawa, Tomonori Tashiro, Yasuki Yamauchi, Takehiro Nagai
  I-PERCEPTION, Volume：8, First page：48, Last page：49, Jul. 2017, [Reviewed]
  English

• Study on color representation in human cortex based on individual differences in perception and brain activity　　　　　　　　　　　　　　　
  JSPS, Grant-in-aid for Scientific Research, Class A, Apr. 2024 - Mar. 2028
  Ichiro Kuriki; Masami K Yamaguchi; So Kanazawa; Sae Kaneko; Takehiro Nagai; Jiale Yang; Kenichi Ueno; Hiroaki Kiyokawa, Saitama University
  Grant amount(Total)：47710000, Direct funding：36700000, Indirect funding：11010000
  Grant number：24H00702
• 視覚情報工学アプローチによる感性的質感知覚メカニズムの解明　　　　　　　　　　　　　　　
  01 Apr. 2023 - 31 Mar. 2026
  Grant amount(Total)：3380000, Direct funding：2600000, Indirect funding：780000
  Grant number：23K16985