「领域快报 002期」社交及语言

「领域快报」是AiBrain筹备的特别栏目，是由海内外知名高校的一线青年科研工作者(博士后、PI）精选的领域科研动态，旨在为学科融合、交叉合作提供平台和机遇。

002

「领域快报」社交及语言

PROFILE

作者：王铂

博士后 - 加州理工学院

研究领域：语言交流

社交记忆的环路基础

海马CA2区对于社交信息相关的记忆至关重要。本文的作者研究了CA2区的主要输入通路，（包括来自外侧内嗅皮层（LEC），内侧内嗅皮层（MEC）以及海马齿状回（DG）的输入），以及这些通路在社交记忆的储存和提取过程中的功能。在小鼠与陌生同类进行互动（形成社交信息记忆），或者之后进行亲疏分辨实验（社会记忆提取）的过程中，选择性地抑制LEC到CA2的直接输入都能够显著地破坏社交记忆的形成或提取。而MEC或者DG到CA2的通路则不参与社交记忆的相关功能。这项研究进一步地完善了我们对于社交记忆环路的理解，阐明了CA2接收到的社交信息来源于LEC。

关键词：

social memory，lateral entorhinal cortex，hippocampus

文章链接：

https://www.sciencedirect.com/science/article/pii/S089662732200085X

Summary

The hippocampus is essential for different forms of declarative memory, including social memory, the ability to recognize and remember a conspecific. Although recent studies identify the importance of the dorsal CA2 region of the hippocampus in social memory storage, little is known about its sources of social information. Because CA2, like other hippocampal regions, receives its major source of spatial and non-spatial information from the medial and lateral subdivisions of entorhinal cortex (MEC and LEC), respectively, we investigated the importance of these inputs for social memory. Whereas MEC inputs to CA2 are dispensable, the direct inputs to CA2 from LEC are both selectively activated during social exploration and required for social memory. This selective behavioral role of LEC is reflected in the stronger excitatory drive it provides to CA2 compared with MEC. Thus, a direct LEC → CA2 circuit is tuned to convey social information that is critical for social memory.

大脑皮层对歌曲的表征

作者在受试病人的脑中进行了皮层脑电（EcoG）记录，并且利用新开发的组分分解统计算法分析了听觉皮层对自然界常见的多种声音的表征。根据他们的分析推演，人类大脑听觉皮层中存在一个神经元亚群，选择性地响应于（由人类演唱的）歌曲（song）反应的神经元亚群，而它们对（不含有旋律的）语言（speech）或者（不含有语言信息的）音乐（instrumental music）没有反应。在空间分布上，歌曲选择性神经亚群处于高级听觉皮层中，位于语言选择性和音乐选择性区域之间。这项研究有助于人们进一步解析处理语言、音乐等声音信息的大脑机制。

关键词：

electrocorticography，neural representation of music，component decomposition algorithm

文章链接：

https://www.sciencedirect.com/science/article/pii/S0960982222001312

Abstract

How is music represented in the brain? While neuroimaging has revealed some spatial segregation between responses to music versus other sounds, little is known about the neural code for music itself. To address this question, we developed a method to infer canonical response components of human auditory cortex using intracranial responses to natural sounds, and further used the superior coverage of fMRI to map their spatial distribution. The inferred components replicated many prior findings, including distinct neural selectivity for speech and music, but also revealed a novel component that responded nearly exclusively to music with singing. Song selectivity was not explainable by standard acoustic features, was located near speech- and music-selective responses and was also evident in individual electrodes. These results suggest that representations of music are fractionated into subpopulations selective for different types of music, one of which is specialized for the analysis of song.

音调信息在大脑中的处理

在人类的语言交流中，相当一部分信息是通过音调变化（pitch modulation）来传达的。例如，结尾处的升调通常表达疑问语气，降调表达陈述语气。对于这种音调语言（tonal language）来说，仅仅是音调变化模式不同，就足以表达完全不同的语义。本文中，作者给受试人员听了几组声音，同时做了高密度脑电记录（EEG），以及事件相关电位分析。他们发现，句尾音调不同（声调或降调）但是词语组成顺序完全相同的两句话在播放结束后，所诱发的事件相关电位幅度在100 ms左右就会出现显著的差异。然而，如果移除两句话中所包含的语义信息，但保留它们各自的音调特征，那么语句所诱发的事件相关电位则没有显著性差别。这提示了人类大脑对于音调变化所包含信息的处理是快速的，而且需要与相应的语义处理相协同。

关键词:

Communicative Functions，speech prosody，pitch，electroencephalography（EEG）

文章链接：

https://academic.oup.com/cercor/advance-article/doi/10.1093/cercor/bhab522/6524018

Abstract

During conversations, speech prosody provides important clues about the speaker’s communicative intentions. In many languages, a rising vocal pitch at the end of a sentence typically expresses a question function, whereas a falling pitch suggests a statement. Here, the neurophysiological basis of intonation and speech act understanding were investigated with high-density electroencephalography (EEG) to determine whether prosodic features are reflected at the neurophysiological level. Already approximately 100 ms after the sentence-final word differing in prosody, questions, and statements expressed with the same sentences led to different neurophysiological activity recorded in the event-related potential. Interestingly, low-pass filtered sentences and acoustically matched nonvocal musical signals failed to show any neurophysiological dissociations, thus suggesting that the physical intonation alone cannot explain this modulation. Our results show rapid neurophysiological indexes of prosodic communicative information processing that emerge only when pragmatic and lexico-semantic information are fully expressed. The early enhancement of question-related activity compared with statements was due to sources in the articulatory-motor region, which may reflect the richer action knowledge immanent to questions, namely the expectation of the partner action of answering the question. The present findings demonstrate a neurophysiological correlate of prosodic communicative information processing, which enables humans to rapidly detect and understand speaker intentions in linguistic interactions.

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