Smith Fraser W, Goodale Melvyn A
School of Psychology, University of East Anglia, Norwich NR4 7TJ, UK The Brain and Mind Institute, University of Western Ontario, London, ON, Canada N6A 5B7.
The Brain and Mind Institute, University of Western Ontario, London, ON, Canada N6A 5B7.
Cereb Cortex. 2015 Apr;25(4):1020-31. doi: 10.1093/cercor/bht292. Epub 2013 Oct 11.
Neurons, even in the earliest sensory areas of cortex, are subject to a great deal of contextual influence from both within and across modality connections. In the present work, we investigated whether the earliest regions of somatosensory cortex (S1 and S2) would contain content-specific information about visual object categories. We reasoned that this might be possible due to the associations formed through experience that link different sensory aspects of a given object. Participants were presented with visual images of different object categories in 2 fMRI experiments. Multivariate pattern analysis revealed reliable decoding of familiar visual object category in bilateral S1 (i.e., postcentral gyri) and right S2. We further show that this decoding is observed for familiar but not unfamiliar visual objects in S1. In addition, whole-brain searchlight decoding analyses revealed several areas in the parietal lobe that could mediate the observed context effects between vision and somatosensation. These results demonstrate that even the first cortical stages of somatosensory processing carry information about the category of visually presented familiar objects.
神经元，即使是在皮层最早的感觉区域，也会受到来自模态内和跨模态连接的大量情境影响。在本研究中，我们调查了体感皮层的最早区域（S1和S2）是否会包含有关视觉对象类别的特定内容信息。我们推测这可能是由于通过经验形成的关联将给定对象的不同感官方面联系起来。在两项功能磁共振成像实验中，向参与者展示了不同对象类别的视觉图像。多变量模式分析显示，在双侧S1（即中央后回）和右侧S2中，熟悉的视觉对象类别能够得到可靠解码。我们进一步表明，在S1中，这种解码仅在熟悉的而非不熟悉的视觉对象中观察到。此外，全脑搜索光解码分析揭示了顶叶中的几个区域，这些区域可能介导了观察到的视觉和体感之间的情境效应。这些结果表明，即使是体感处理的第一个皮层阶段也携带有关视觉呈现的熟悉对象类别的信息。
