The discrimination of expressions in facial movements by infants: A study with point-light displays

Perceiving facial expressions is an essential ability for infants. Although previous studies indicated that infants could perceive emotion from expressive facial movements, the developmental change of this ability remains largely unknown. To exclusively examine infants' processing of facial movements, we used point -light displays (PLDs) to present emotionally expressive facial movements. Specifically, we used a habituation and visual paired comparison (VPC) paradigm to investigate whether 3-, 6-, and 9 -month-olds could discriminate between happy and fear PLDs after being habituated with a happy PLD (happy-habituation condition) or a fear PLD (fear-habituation condition). The 3-month-olds dis-criminated between the happy and fear PLDs in both the happy -and fear-habituation conditions. The 6-and 9-month-olds showed discrimination only in the happy-habituation condition but not in the fear-habituation condition. These results indicated a develop-mental change in processing expressive facial movements. Younger infants tended to process low-level motion signals regardless of the depicted emotions, and older infants tended to process expressions, which emerged in familiar facial expressions (e.g., happy). Additional analyses of individual difference and eye movement patterns supported this conclusion. In Experiment 2, we concluded that the findings of Experiment 1 were not due to a spontaneous preference for fear PLDs. Using inverted PLDs, Experiment 3 further suggested that 3-month-olds have already perceived PLDs as face-like stimuli.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

Previous studies have shown that infants can perceive emotions from facial expressions, but the developmental change of this ability is still unclear. Using point-light displays, researchers found that 3-month-old infants could discriminate between happy and fear expressions, while 6-month-old and 9-month-old infants could only do so in the happy condition. This suggests a developmental change in facial expression processing.