Department of Psychological Sciences, Kansas State University, Manhattan, KS 66506, USA.
University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Neuroscience. 2022 Aug 1;496:243-260. doi: 10.1016/j.neuroscience.2022.05.033. Epub 2022 May 30.
Evidence has suggested that the ventrolateral prefrontal cortex (VLPFC) processes social stimuli, including faces and vocalizations, which are essential for communication. Features embedded within audiovisual stimuli, including emotional expression and caller identity, provide abundant information about an individual's intention, emotional state, motivation, and social status, which are important to encode in a social exchange. However, it is unknown to what extent the VLPFC encodes such features. To investigate the role of VLPFC during social communication, we recorded single-unit activity while rhesus macaques (Macaca mulatta) performed a nonmatch-to-sample task using species-specific face-vocalization stimuli that differed in emotional expression or caller identity. 75% of recorded cells were task-related and of these >70% were responsive during the nonmatch period. A larger proportion of nonmatch cells encoded the stimulus rather than the context of the trial type. A subset of responsive neurons were most commonly modulated by the identity of the nonmatch stimulus and less by the emotional expression, or both features within the face-vocalization stimuli presented during the nonmatch period. Neurons encoding identity were found in VLPFC across a broader region than expression related cells which were confined to only the anterolateral portion of the recording chamber in VLPFC. These findings suggest that, within a working memory paradigm, VLPFC processes features of face and vocal stimuli, such as emotional expression and identity, in addition to task and contextual information. Thus, stimulus and contextual information may be integrated by VLPFC during social communication.
有证据表明，腹外侧前额叶皮层（VLPFC）处理社交刺激，包括面孔和声音，这对于交流至关重要。视听刺激中嵌入的特征，包括表情和来电者身份，提供了有关个体意图、情绪状态、动机和社会地位的丰富信息，这些信息对于社会交流中的编码很重要。然而，目前尚不清楚 VLPFC 在多大程度上对这些特征进行编码。为了研究 VLPFC 在社交交流中的作用，我们在恒河猴（Macaca mulatta）执行使用特定于物种的面孔-声音刺激进行的非匹配样本任务时记录了单个单元的活动，这些刺激在情绪表达或来电者身份上有所不同。记录的细胞中有 75%与任务相关，其中超过 70%在非匹配期有反应。更多的非匹配细胞编码刺激而不是试验类型的上下文。响应神经元的一部分最常被非匹配刺激的身份所调节，而较少被非匹配期呈现的面孔-声音刺激中的情绪表达或两者共同调节。在 VLPFC 中发现了编码身份的神经元，其分布范围比仅在 VLPFC 记录室的前外侧部分受限的与表情相关的细胞更广泛。这些发现表明，在工作记忆范式中，VLPFC 处理面孔和声音刺激的特征，如情绪表达和身份，以及任务和上下文信息。因此，刺激和上下文信息可能在社交交流中通过 VLPFC 进行整合。
