Tong Renjie, Su Shaoyi, Liang Ying, Li Chunlin, Sun Liwei, Zhang Xu
School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China.
Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Beijing, 100069, China.
Neurosci Bull. 2025 Feb;41(2):261-271. doi: 10.1007/s12264-024-01312-0. Epub 2024 Oct 29.
The ability to localize sound sources rapidly allows human beings to efficiently understand the surrounding environment. Previous studies have suggested that there is an auditory "where" pathway in the cortex for processing sound locations. The neural activation in regions along this pathway encodes sound locations by opponent hemifield coding, in which each unilateral region is activated by sounds coming from the contralateral hemifield. However, it is still unclear how these regions interact with each other to form a unified representation of the auditory space. In the present study, we investigated whether functional connectivity in the auditory "where" pathway encoded sound locations during passive listening. Participants underwent functional magnetic resonance imaging while passively listening to sounds from five distinct horizontal locations (-90°, -45°, 0°, 45°, 90°). We were able to decode sound locations from the functional connectivity patterns of the "where" pathway. Furthermore, we found that such neural representation of sound locations was primarily based on the coding of sound lateralization angles to the frontal midline. In addition, whole-brain analysis indicated that functional connectivity between occipital regions and the primary auditory cortex also encoded sound locations by lateralization angles. Overall, our results reveal a lateralization-angle-based representation of sound locations encoded by functional connectivity patterns, which could add on the activation-based opponent hemifield coding to provide a more precise representation of the auditory space.
快速定位声源的能力使人类能够有效地理解周围环境。先前的研究表明，在皮层中存在一条用于处理声音位置的听觉“位置”通路。沿着这条通路的区域中的神经激活通过对侧半视野编码来编码声音位置，其中每个单侧区域由来自对侧半视野的声音激活。然而，这些区域如何相互作用以形成听觉空间的统一表征仍不清楚。在本研究中，我们调查了在被动聆听期间，听觉“位置”通路中的功能连接是否对声音位置进行了编码。参与者在被动聆听来自五个不同水平位置（-90°、-45°、0°、45°、90°）的声音时接受了功能磁共振成像检查。我们能够从“位置”通路的功能连接模式中解码声音位置。此外，我们发现这种声音位置的神经表征主要基于声音相对于额中线的偏侧化角度编码。此外，全脑分析表明，枕叶区域与初级听觉皮层之间的功能连接也通过偏侧化角度对声音位置进行了编码。总体而言，我们的结果揭示了一种由功能连接模式编码的基于偏侧化角度的声音位置表征，这可以补充基于激活的对侧半视野编码，以提供更精确的听觉空间表征。
