Bailey Kerri M, Giordano Bruno L, Kaas Amanda L, Smith Fraser W
School of Psychology, University of East Anglia, Norwich NR4 7TJ, United Kingdom.
Institut des Neurosciences de La Timone, CNRS UMR 7289, Université Aix-Marseille, Marseille CNRS UMR 7289, France.
Cereb Cortex. 2023 Mar 21;33(7):3621-3635. doi: 10.1093/cercor/bhac296.
Neurons, even in the earliest sensory regions of cortex, are subject to a great deal of contextual influences from both within and across modality connections. Recent work has shown that primary sensory areas can respond to and, in some cases, discriminate stimuli that are not of their target modality: for example, primary somatosensory cortex (SI) discriminates visual images of graspable objects. In the present work, we investigated whether SI would discriminate sounds depicting hand-object interactions (e.g. bouncing a ball). In a rapid event-related functional magnetic resonance imaging experiment, participants listened attentively to sounds from 3 categories: hand-object interactions, and control categories of pure tones and animal vocalizations, while performing a one-back repetition detection task. Multivoxel pattern analysis revealed significant decoding of hand-object interaction sounds within SI, but not for either control category. Crucially, in the hand-sensitive voxels defined from an independent tactile localizer, decoding accuracies were significantly higher for hand-object interactions compared to pure tones in left SI. Our findings indicate that simply hearing sounds depicting familiar hand-object interactions elicit different patterns of activity in SI, despite the complete absence of tactile stimulation. These results highlight the rich contextual information that can be transmitted across sensory modalities even to primary sensory areas.
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。最近的研究表明，初级感觉区域能够对非其目标模态的刺激做出反应，并且在某些情况下能够区分这些刺激：例如，初级体感皮层（SI）能够区分可抓握物体的视觉图像。在本研究中，我们调查了SI是否能够区分描绘手与物体相互作用的声音（例如，拍球）。在一项快速事件相关功能磁共振成像实验中，参与者在执行一项单后重复检测任务时，专心聆听来自3类声音：手与物体相互作用的声音，以及纯音和动物叫声的对照类别。多体素模式分析显示，SI内对手与物体相互作用声音有显著解码，但对任何一个对照类别都没有。至关重要的是，在由独立触觉定位器定义的手部敏感体素中，与左SI中的纯音相比，手与物体相互作用声音的解码准确率显著更高（。我们的研究结果表明，仅仅听到描绘熟悉的手与物体相互作用的声音，即使完全没有触觉刺激，也会在SI中引发不同的活动模式。这些结果凸显了即使是向初级感觉区域也能跨感觉模态传递的丰富情境信息。
