Department of Neuroscience, Baylor College of Medicine, Houston, One Baylor Plaza, Houston, TX, USA.
Cereb Cortex. 2018 Nov 1;28(11):3908-3921. doi: 10.1093/cercor/bhx255.
Recent studies have challenged the traditional notion of modality-dedicated cortical systems by showing that audition and touch evoke responses in the same sensory brain regions. While much of this work has focused on somatosensory responses in auditory regions, fewer studies have investigated sound responses and representations in somatosensory regions. In this functional magnetic resonance imaging (fMRI) study, we measured BOLD signal changes in participants performing an auditory frequency discrimination task and characterized activation patterns related to stimulus frequency using both univariate and multivariate analysis approaches. Outside of bilateral temporal lobe regions, we observed robust and frequency-specific responses to auditory stimulation in classically defined somatosensory areas. Moreover, using representational similarity analysis to define the relationships between multi-voxel activation patterns for all sound pairs, we found clear similarity patterns for auditory responses in the parietal lobe that correlated significantly with perceptual similarity judgments. Our results demonstrate that auditory frequency representations can be distributed over brain regions traditionally considered to be dedicated to somatosensation. The broad distribution of auditory and tactile responses over parietal and temporal regions reveals a number of candidate brain areas that could support general temporal frequency processing and mediate the extensive and robust perceptual interactions between audition and touch.
最近的研究挑战了传统的模态专用皮质系统的概念，表明听觉和触觉在相同的感觉脑区引起反应。虽然这项工作的很大一部分集中在听觉区域的体感反应上，但很少有研究调查声音反应和体感区域的表示。在这项功能磁共振成像（fMRI）研究中，我们测量了参与者在执行听觉频率辨别任务时的 BOLD 信号变化，并使用单变量和多变量分析方法来描述与刺激频率相关的激活模式。在双侧颞叶区域之外，我们观察到经典定义的体感区域对听觉刺激有强烈的、特定于频率的反应。此外，我们使用表示相似性分析来定义所有声音对的多体素激活模式之间的关系，发现顶叶的听觉反应具有明显的相似模式，与感知相似性判断显著相关。我们的结果表明，听觉频率的表示可以分布在传统上被认为专门用于体感的大脑区域。听觉和触觉反应在顶叶和颞叶区域的广泛分布揭示了许多候选脑区，这些脑区可能支持一般的时间频率处理，并介导听觉和触觉之间广泛而强烈的感知相互作用。
