Berto Martina, Reisinger Patrick, Ricciardi Emiliano, Weisz Nathan, Bottari Davide
Molecular Mind Lab, IMT School for Advanced Studies Lucca, Italy.
Department of Psychology and Centre for Cognitive Neuroscience, Paris-Lodron-University of Salzburg, Austria.
Cortex. 2025 Mar;184:79-95. doi: 10.1016/j.cortex.2024.09.020. Epub 2025 Jan 7.
The processing of stationary sounds relies on both local features and compact representations. As local information is compressed into summary statistics, abstract representations emerge. Whether the brain is endowed with distinct neural architectures predisposed to such computations is unknown. In this magnetoencephalography (MEG) study, we employed a validated protocol to localize cortical correlates of local and summary auditory representations, exposing participants to sequences embedding triplets of synthetic sound textures systematically varying for either local details or summary statistics. Sounds varied for their duration and could be short (40 ms) or long (478 ms) to favor change detections based on local or summary statistics, respectively. Results clearly revealed distinct activation patterns for local features and summary auditory statistics. Neural activations diverged in magnitude, spatiotemporal distribution, and hemispheric lateralization. The right auditory cortex, comprising both primary and neighboring temporal and frontal regions were engaged to detect sound changes in both local features (for short sounds) and summary statistics (for long sounds). Conversely, the left auditory cortex was not selective to these auditory changes. However, the ventro-lateral portion of left frontal lobe, a region associated with sound recognition, was engaged in processing changes in summary statistics at a long sound duration. These findings highlight the involvement of distinct cortical pathways and hemispheric lateralization for the computation of local and summary acoustic information occurring at different temporal resolutions. SIGNIFICANT STATEMENT: We revealed hemispheric specializations for auditory computations at high (local) and low (summary statistics) temporal resolutions. The right hemisphere was engaged for both computations, while the left hemisphere responded more to summary statistics changes. These findings highlight the multifaceted functions of the right hemisphere in capturing acoustic properties of stationary sounds and the left hemisphere's involvement in processing abstract representations.
静止声音的处理依赖于局部特征和紧凑表征。随着局部信息被压缩为汇总统计量，抽象表征得以出现。大脑是否具备倾向于此类计算的独特神经结构尚不清楚。在这项脑磁图（MEG）研究中，我们采用了一种经过验证的方案来定位局部和汇总听觉表征的皮质相关物，让参与者接触嵌入合成声音纹理三元组的序列，这些三元组在局部细节或汇总统计方面系统地变化。声音的持续时间不同，可以是短的（40毫秒）或长的（478毫秒），分别有利于基于局部或汇总统计的变化检测。结果清楚地揭示了局部特征和汇总听觉统计的不同激活模式。神经激活在幅度、时空分布和半球侧化方面存在差异。右侧听觉皮层，包括初级以及相邻的颞叶和额叶区域，参与检测局部特征（短声音）和汇总统计（长声音）方面的声音变化。相反，左侧听觉皮层对这些听觉变化没有选择性。然而，左侧额叶的腹外侧部分，一个与声音识别相关的区域，在长声音持续时间时参与处理汇总统计的变化。这些发现突出了不同皮质通路和半球侧化在以不同时间分辨率进行局部和汇总声学信息计算中的作用。重要声明：我们揭示了在高（局部）和低（汇总统计）时间分辨率下听觉计算的半球特化。右侧半球参与了这两种计算，而左侧半球对汇总统计变化的反应更强。这些发现突出了右侧半球在捕捉静止声音声学特性方面的多方面功能以及左侧半球在处理抽象表征中的参与。
