Suchergebnisse

AbstractParental responsiveness and synchronization during early face‐to‐face interactions between mother and infant have been theorized to affect a broad spectrum of positive developmental outcomes in social and cognitive infant growth and to facilitate the development of a sense of self in the baby. Here we show that being imitated can significantly affect the behavior of nursery‐reared infant monkeys, which are at an increased risk for developing aberrant social behaviors. Infants look longer and lipsmack more at an experimenter both during imitation and after being imitated. These results demonstrate that from early in life imitation might be used as a privileged form of communication by adults to enhance infants' visual engagement and their social communication. Imitation may therefore be useful to counteract the negative effects of early social adversities.

AbstractAcross all languages studied to date, audiovisual speech exhibits a consistent rhythmic structure. This rhythm is critical to speech perception. Some have suggested that the speech rhythm evolved de novo in humans. An alternative account – the one we explored here – is that the rhythm of speech evolved through the modification of rhythmic facial expressions. We tested this idea by investigating the structure and development of macaque monkey lipsmacks and found that their developmental trajectory is strikingly similar to the one that leads from human infant babbling to adult speech. Specifically, we show that: (1) younger monkeys produce slower, more variable mouth movements and as they get older, these movements become faster and less variable; and (2) this developmental pattern does not occur for another cyclical mouth movement – chewing. These patterns parallel human developmental patterns for speech and chewing. They suggest that, in both species, the two types of rhythmic mouth movements use different underlying neural circuits that develop in different ways. Ultimately, both lipsmacking and speech converge on a ∼5 Hz rhythm that represents the frequency that characterizes the speech rhythm of human adults. We conclude that monkey lipsmacking and human speech share a homologous developmental mechanism, lending strong empirical support to the idea that the human speech rhythm evolved from the rhythmic facial expressions of our primate ancestors.

AbstractIn human infants, neonatal imitation and preferences for eyes are both associated with later social and communicative skills, yet the relationship between these abilities remains unexplored. Here we investigated whether neonatal imitation predicts facial viewing patterns in infant rhesus macaques. We first assessed infant macaques for lipsmacking (a core affiliative gesture) and tongue protrusion imitation in the first week of life. When infants were 10–28 days old, we presented them with an animated macaque avatar displaying a still face followed by lipsmacking or tongue protrusion movements. Using eye tracking technology, we found that macaque infants generally looked equally at the eyes and mouth during gesture presentation, but only lipsmacking‐imitators showed significantly more looking at the eyes of the neutral still face. These results suggest that neonatal imitation performance may be an early measure of social attention biases and might potentially facilitate the identification of infants at risk for atypical social development.

AbstractRecent reports of similar patterns of brain electrical activity (electroencephalogram: EEG) during action execution and observation, recorded from scalp locations over motor‐related regions in infants and adults, have raised the possibility that two foundational abilities – controlling one's own intentional actions and perceiving others' actions – may be integrally related during ontogeny. However, to our knowledge, there are no published reports of the relations between developments in motor skill (i.e. recording actual motor skill performance) and EEG during both action execution and action observation. In the present study we collected EEG from 21 9‐month‐olds who were given opportunities to reach for toys and who also observed an experimenter reach for toys. Event‐related desynchronization (ERD) was computed from the EEG during the reaching events. We assessed infants' reaching‐grasping competence, including reach latency, errors, preshaping of the hand, and bimanual reaches, and found that desynchronization recorded in scalp electrodes over motor‐related regions during action observation was associated with action competence during execution. Infants who were more competent reachers, compared to less competent reachers, exhibited greater ERD while observing reaching‐grasping. These results provide initial evidence for an early emerging neural system integrating one's own actions with the perception of others' actions.

AbstractThe meaning, mechanism, and function of imitation in early infancy have been actively discussed since Meltzoff and Moore's (1977) report of facial and manual imitation by human neonates. Oostenbroek et al. (2016) claim to challenge the existence of early imitation and to counter all interpretations so far offered. Such claims, if true, would have implications for theories of social‐cognitive development. Here we identify 11 flaws in Oostenbroek et al.'s experimental design that biased the results toward null effects. We requested and obtained the authors' raw data. Contrary to the authors' conclusions, new analyses reveal significant tongue‐protrusion imitation at all four ages tested (1, 3, 6, and 9 weeks old). We explain how the authors missed this pattern and offer five recommendations for designing future experiments. Infant imitation raises fundamental issues about action representation, social learning, and brain–behavior relations. The debate about the origins and development of imitation reflects its importance to theories of developmental science.