Face shape and surface textures are two important cues that aid in the perception of facial expressions of emotion. Additionally, this perception is also influenced by high-level emotion concepts. Across two studies, we use representational similarity analysis to investigate the relative roles of shape, surface, and conceptual information in the perception, categorisation, and neural representation of facial expressions. In Study 1, 50 participants completed a perceptual task designed to measure the perceptual similarity of expression pairs, and a categorical task designed to measure the confusability between expression pairs when assigning emotion labels to a face. We used representational similarity analysis and constructed three models of the similarities between emotions using distinct information. Two models were based on stimulus-based cues (face shapes and surface textures) and one model was based on emotion concepts. Using multiple linear regression, we found that behaviour during both tasks was related with the similarity of emotion concepts. The model based on face shapes was more related with behaviour in the perceptual task than in the categorical, and the model based on surface textures was more related with behaviour in the categorical than the perceptual task. In Study 2, 30 participants viewed facial expressions while undergoing fMRI, allowing for the measurement of brain representational geometries of facial expressions of emotion in three core face-responsive regions (the Fusiform Face Area, Occipital Face Area, and Superior Temporal Sulcus), and a region involved in theory of mind (Medial Prefrontal Cortex). Across all four regions, the representational distances between facial expression pairs were related to the similarities of emotion concepts, but not to either of the stimulus-based cues. Together, these results highlight the important top-down influence of high-level emotion concepts both in behavioural tasks and in the neural representation of facial expressions.

面部形状和表面纹理是有助于感知面部表情的两个重要线索。此外，这种感知也受到高级情感概念的影响。在两项研究中，我们使用表征相似性分析来研究形状、表面和概念信息在面部表情的感知、分类和神经表征中的相对作用。在研究 1 中，50 名参与者完成了一项旨在测量表情对的感知相似性的感知任务，以及一项旨在测量在为面部分配情感标签时表情对之间的混淆性的分类任务。我们使用代表性相似性分析，并使用不同的信息构建了三个情绪之间的相似性模型。两种模型基于基于刺激的线索（面部形状和表面纹理），一种模型基于情感概念。使用多元线性回归，我们发现两个任务中的行为都与情感概念的相似性有关。基于面部形状的模型与感知任务中的行为相关性高于分类任务中的相关性，基于表面纹理的模型与分类任务中的行为相关性高于感知任务中的行为。在研究 2 中，30 名参与者在接受 fMRI 时观察面部表情，从而可以测量三个核心面部反应区域（梭状面部区域、枕面部区域和颞上沟）中情绪面部表情的大脑代表性几何形状，以及涉及心智理论的区域（内侧前额叶皮层）。在所有四个区域中，面部表情对之间的表征距离与情绪概念的相似性有关，但与任何一个基于刺激的线索无关。总之，这些结果突出了高级情感概念在行为任务和面部表情的神经表征中的自上而下的重要影响。