Department of Psychology, University of York, York, UK.
Biosciences Institute and School of Psychology, Newcastle University, Newcastle upon Tyne, UK.
Infancy. 2023 Jul-Aug;28(4):820-835. doi: 10.1111/infa.12535. Epub 2023 Mar 14.
Human body postures provide perceptual cues that can be used to discriminate and recognize emotions. It was previously found that 7-months-olds' fixation patterns discriminated fear from other emotion body expressions but it is not clear whether they also process the emotional content of those expressions. The emotional content of visual stimuli can increase arousal level resulting in pupil dilations. To provide evidence that infants also process the emotional content of expressions, we analyzed variations in pupil in response to emotion stimuli. Forty-eight 7-months-old infants viewed adult body postures expressing anger, fear, happiness and neutral expressions, while their pupil size was measured. There was a significant emotion effect between 1040 and 1640 ms after image onset, when fear elicited larger pupil dilations than neutral expressions. A similar trend was found for anger expressions. Our results suggest that infants have increased arousal to negative-valence body expressions. Thus, in combination with previous fixation results, the pupil data show that infants as young as 7-months can perceptually discriminate static body expressions and process the emotional content of those expressions. The results extend information about infant processing of emotion expressions conveyed through other means (e.g., faces).
人体姿势提供了可以用来区分和识别情绪的知觉线索。先前的研究发现，7 个月大的婴儿会根据注视模式区分恐惧和其他情绪的身体表情，但不清楚他们是否也会处理这些表情的情绪内容。视觉刺激的情绪内容会增加唤醒水平，导致瞳孔扩张。为了提供证据表明婴儿也会处理表情的情绪内容，我们分析了瞳孔对情绪刺激的变化。48 名 7 个月大的婴儿观看了表达愤怒、恐惧、快乐和中性表情的成人身体姿势，同时测量了他们的瞳孔大小。在图像出现后 1040 到 1640 毫秒之间，恐惧引起的瞳孔扩张比中性表情大，存在显著的情绪效应。愤怒表情也存在类似的趋势。我们的结果表明，婴儿对负性价值的身体表情会产生更高的唤醒。因此，结合之前的注视结果，瞳孔数据表明，7 个月大的婴儿可以感知地区分静态身体表情，并处理这些表情的情绪内容。研究结果扩展了有关婴儿通过其他方式（例如，面部）传达的情绪表情处理的信息。
