Institut de Neurosciences des Systèmes (INS), Inserm/UMR1106, Aix Marseille University, 27 Bd Jean Moulin, Marseille 13005, France.
Montreal Neurological Institute (MNI), Cognitive Neuroscience Unit, McGill University, 3801 Rue University, Montréal, QC H3A 2B4, Canada.
Cereb Cortex. 2024 Jul 3;34(7). doi: 10.1093/cercor/bhae292.
What is the function of auditory hemispheric asymmetry? We propose that the identification of sound sources relies on the asymmetric processing of two complementary and perceptually relevant acoustic invariants: actions and objects. In a large dataset of environmental sounds, we observed that temporal and spectral modulations display only weak covariation. We then synthesized auditory stimuli by simulating various actions (frictions) occurring on different objects (solid surfaces). Behaviorally, discrimination of actions relies on temporal modulations, while discrimination of objects relies on spectral modulations. Functional magnetic resonance imaging data showed that actions and objects are decoded in the left and right hemispheres, respectively, in bilateral superior temporal and left inferior frontal regions. This asymmetry reflects a generic differential processing-through differential neural sensitivity to temporal and spectral modulations present in environmental sounds-that supports the efficient categorization of actions and objects. These results support an ecologically valid framework of the functional role of auditory brain asymmetry.
听觉大脑不对称的功能是什么？我们提出，声源的识别依赖于对两个互补且在感知上相关的声学不变量的不对称处理：动作和物体。在一个大型环境声音数据集，我们观察到，时间和频谱调制仅显示出微弱的相关性。然后，我们通过模拟不同物体（固体表面）上发生的各种动作（摩擦）来合成听觉刺激。行为上，动作的区分依赖于时间调制，而物体的区分则依赖于频谱调制。功能磁共振成像数据显示，动作和物体分别在双侧颞上区和左侧额下回被解码。这种不对称反映了一种通用的差异处理——通过对环境声音中存在的时间和频谱调制的不同神经敏感性——支持对动作和物体的高效分类。这些结果支持了听觉大脑不对称的功能作用的一个具有生态效度的框架。
