抄録
物体表面の光沢知覚に関わる神経基盤の解明に向けて機能的磁気共鳴画像法による実験を行った.視覚刺激として光沢レベルの異なる物体をCGにより再現した.また,光沢知覚に相関する血中酸素レベル依存応答を単なる刺激の輝度への応答から分離するため,刺激物体に対する照明条件を統制した.脳表面図に基づく集団解析の結果より,横後頭溝および腹側後頭部が光沢知覚に関わる領域と示唆された.さらに,それら賦活領域に対応する視覚野を網膜部位再現に基づき同定し関心領域解析を行った.その結果,V3AおよびhV4におけるBOLD信号変化率は照明レベルではなく光沢レベルの変化に対応した傾向を示し,一方で,V1は単なる輝度変化に対応した傾向を示した.
A functional magnetic resonance imaging (fMRI) study was conducted to clarify the neural correlates of the perception of surface glossiness. Computer-generated images that simulated objects with different glossiness levels were presented as visual stimuli. The illumination on the objects was also controlled to dissociate the BOLD responce simply correlated with the luminance of the stimuli. From the results of cortical surface-based group analysis, Transverse Occipital Sulcus (TOS) and Ventral Occipital area (VO) were identified that might be involved in glossiness perception. ROI analysis based on retinotopic localizer also revealed the trends of the BOLD signal percent change in V3A and hV4 that well matched with the glossiness level change but not with the illumination level change, while V1 showed the simple trend caused by the luminance change.
