Sun Hua-Chun, Di Luca Massimiliano, Ban Hiroshi, Muryy Alexander, Fleming Roland W, Welchman Andrew E
School of Psychology, University of Birmingham, Birmingham, United Kingdom;
Center for Information and Neural Networks, National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan; Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan;
J Neurophysiol. 2016 Jun 1;115(6):2779-90. doi: 10.1152/jn.00829.2015. Epub 2016 Feb 24.
The visual impression of an object's surface reflectance ("gloss") relies on a range of visual cues, both monocular and binocular. Whereas previous imaging work has identified processing within ventral visual areas as important for monocular cues, little is known about cortical areas involved in processing binocular cues. Here, we used human functional MRI (fMRI) to test for brain areas selectively involved in the processing of binocular cues. We manipulated stereoscopic information to create four conditions that differed in their disparity structure and in the impression of surface gloss that they evoked. We performed multivoxel pattern analysis to find areas whose fMRI responses allow classes of stimuli to be distinguished based on their depth structure vs. material appearance. We show that higher dorsal areas play a role in processing binocular gloss information, in addition to known ventral areas involved in material processing, with ventral area lateral occipital responding to both object shape and surface material properties. Moreover, we tested for similarities between the representation of gloss from binocular cues and monocular cues. Specifically, we tested for transfer in the decoding performance of an algorithm trained on glossy vs. matte objects defined by either binocular or by monocular cues. We found transfer effects from monocular to binocular cues in dorsal visual area V3B/kinetic occipital (KO), suggesting a shared representation of the two cues in this area. These results indicate the involvement of mid- to high-level visual circuitry in the estimation of surface material properties, with V3B/KO potentially playing a role in integrating monocular and binocular cues.
物体表面反射率（“光泽”）的视觉印象依赖于一系列视觉线索，包括单眼线索和双眼线索。尽管先前的成像研究已经确定腹侧视觉区域内的处理对于单眼线索很重要，但对于参与处理双眼线索的皮层区域却知之甚少。在这里，我们使用人类功能磁共振成像（fMRI）来测试选择性参与双眼线索处理的脑区。我们操纵立体信息以创建四种条件，这些条件在视差结构以及它们所唤起的表面光泽印象方面有所不同。我们进行了多体素模式分析，以找到那些fMRI反应能够根据刺激的深度结构与材料外观来区分刺激类别的区域。我们表明，除了已知参与材料处理的腹侧区域外，更高的背侧区域在处理双眼光泽信息中发挥作用，腹侧枕颞外侧区域对物体形状和表面材料特性均有反应。此外，我们测试了双眼线索和单眼线索的光泽表征之间的相似性。具体来说，我们测试了在由双眼或单眼线索定义的光泽物体与哑光物体上训练的算法的解码性能中的迁移情况。我们在背侧视觉区域V3B/运动性枕叶（KO）中发现了从单眼线索到双眼线索的迁移效应，这表明这两种线索在该区域有共享的表征。这些结果表明中高级视觉回路参与了表面材料特性的估计，V3B/KO可能在整合单眼和双眼线索中发挥作用。
