Infants' perception of dynamic affective expressions: do infants distinguish specific expressions?

Seven-month-old infants' perception of positive (happy, interested) and negative (angry, sad) affective expressions was investigated using a preferential looking procedure (n = 20 in each of 6 conditions). The infants saw two videotaped facial expressions and heard a single vocal expression concordant with one of the facial expressions. The voice on the soundtrack was played 5 s out of synchrony with the ongoing affective visual display. Infants participated in one of six conditions (all possible pairs of the four expressive events). Infants' visual fixations to the affectively concordant and affectively discordant displays were recorded. Infants looked longer at the affectively concordant displays than at the affectively discordant displays in all conditions except the happy/sad and interested/sad conditions. For these two comparisons, facial discrimination was demonstrated by the infants' preferential looking at happy and interested expressions compared to the sad expression. Thus, 7-month-old infants discriminate among happy, interested, angry, and sad expressions, demonstrating differentiation among specific, dynamic expressions. The results are discussed in terms of the information specifying facial and vocal affect and the possible role of familiarity in learning to differentiate among affective expressions during infancy.

Intermodal perception of happy and angry expressive behaviors by seven-month-old infants.

2 studies were conducted to examine the roles of facial motion and temporal correspondences in the intermodal perception of happy and angry expressive events. 7-month-old infants saw 2 video facial expressions and heard a single vocal expression characteristic of one of the facial expressions. Infants saw either a normally lighted face (fully illuminated condition) or a moving dot display of a face (point light condition). In Study 1, one woman expressed the affects vocally, another woman expressed the affects facially, and what they said also differed. Infants in the point light condition showed a reliable preference for the affectively concordant displays, while infants in the fully illuminated condition showed no preference for the affectively concordant display. In a second study, the visual and vocal displays were produced by a single individual on one occasion and were presented to infants 5 sec out of synchrony. Infants in both conditions looked longer at the affectively concordant displays. The results of the 2 studies indicate that infants can discriminate happy and angry affective expressions on the basis of motion information, and that the temporal correspondences unifying these affective events may be affect-specific rhythms.

Children's understanding of action lines and the static representation of speed of locomotion.

Children's understanding of the static representation of speed of locomotion was explored in 2 experiments. In Experiment 1, 20 7-year-olds and 20 9-year-olds drew pictures of 2 people walking and running at different speeds. Children then made judgments about pairs of unambiguous drawings of a person walking or running, as did a sample of 20 adults. The drawings varied according to whether action lines, background lines, or no lines were present. Children were asked to say which figure appeared to be moving faster. In Experiment 2, 20 7-year-olds, 20 9-year-olds, and 21 adults sorted ambiguous drawings of a person walking and running at different speeds. The pictures again contained action lines, background lines, or no lines. In the drawing task, children more frequently used page position and biomechanical information than action lines to represent fast and slow walking and running. In the judgment task, 7- and 9-year-olds offered equivalent judgments of action lines and background lines, whereas adults distinguished between these pictorial devices. In the sorting task, all subjects distinguished between action lines and background lines and judged that pictures containing action lines looked faster than pictures containing background lines and pictures without lines. Taken together, the results indicate that subjects' judgments were influenced by the form of locomotion and degree of ambiguity in the depicted events they saw. The findings are consistent with the view that different categories of pictorial devices exist, but the effectiveness of each device is contingent upon the perceiver's experience with it and the context in which it appears.