Correction: The modulation of facial mimicry by attachment tendencies and their underlying affiliation motives in 3-year-olds: An EMG study

Infants' facial electromyographic responses to the sight of emotional interpersonal touch

Adult studies have shown that observed interpersonal touch provides crucial information about others' emotional states. Yet, despite the unique communicative function of touch during development, very little is known about infants' sensitivity to the emotional valence of observed touches. To investigate this issue, we measured facial electromyographic (EMG) activity in response to positive (caress) and negative (scratches) observed touches in a sample of 11-month-old infants. Facial EMG activity was measured over the zygomaticus major (ZM) and corrugator supercilii muscles, respectively involved in positive (i.e., smiling) and negative (i.e., frowning) facial expressions. Results have shown distinct activations of the ZM during the observation of scratches and caresses. In particular, significantly greater activation of the ZM (smiling muscle) emerged specifically in response to the observation of caresses compared to scratches. Our finding suggests that, in infancy, observed affective touches can evoke emotional facial reactions.

Infants' sensitivity to emotional expressions in actions: The contributions of parental expressivity and motor experience

Actions can convey information about the affective state of an actor. By the end of the first year, infants show sensitivity to such emotional information in actions. Here, we examined the mechanisms contributing to infants' developing sensitivity to emotional action kinematics. We hypothesized that this sensitivity might rely on two factors: a stable motor representation of the observed action to be able to detect deviations from how it would typically be performed and experience with emotional expressions. The sensitivity of 12- to 13-month-old infants to happy and angry emotional cues in a manual transport action was examined using facial EMG. Infants' own movements when performing an object transport task were assessed using optical motion capture. The infants' caregivers' emotional expressivity was measured using a questionnaire. Negative emotional expressivity of the primary caregiver was significantly related to infants' sensitivity to observed angry actions. There was no evidence for such an association with infants' own motor skill. Overall, our results show that infants' experience with emotions, measured as caregivers' emotional expressivity, may aid infants' discrimination of others' emotions expressed in action kinematics.