The role of sensorimotor experience in the development of mimicry in infancy

During social interactions we often have an automatic and unconscious tendency to copy or 'mimic' others' actions. The dominant view on the neural basis of mimicry appeals to an automatic coupling between perception and action. It has been suggested that this coupling is formed through associative learning during correlated sensorimotor experience. Although studies with adult participants have provided support for this hypothesis, little is known about the role of sensorimotor experience in supporting the development of perceptual-motor couplings, and consequently mimicry behaviour, in infancy. Here we investigated whether the extent to which an observed action elicits mimicry depends on the opportunity an infant has had to develop perceptual-motor couplings for this action through correlated sensorimotor experience. We found that mothers' tendency to imitate their 4-month-olds' facial expressions during a parent-child interaction session was related to infants' facial mimicry as measured by EMG. Maternal facial imitation was not related to infants' mimicry of hand actions, and instead we found preliminary evidence that infants' tendency to look at their own hands may be related to their tendency to mimic hand actions. These results are consistent with the idea that mimicry is supported by perceptual-motor couplings that are formed through correlated sensorimotor experience obtained by observing one's own actions and imitative social partners. This article is protected by copyright. All rights reserved. [Abstract copyright: This article is protected by copyright. All rights reserved.

Measuring and Modulating Mimicry: Insights from Virtual Reality and Autism

Mimicry involves the unconscious imitation of other people’s behaviour. The social top-down response modulation (STORM) model has suggested that mimicry is a socially strategic behaviour which is modulated according to the social context, for example, we mimic more when someone is looking at us or if we want to affiliate with them. There has been a long debate over whether mimicry is different in autism, a condition characterised by differences in social interaction. STORM predicts that autistic people can and do mimic but do not change their mimicry behaviour according to the social context. Using a range of mimicry measures this thesis aimed to test STORM’s predictions. The first study employed a traditional reaction time measure of mimicry and demonstrated that direct gaze socially modulated mimicry responses in non-autistic adults but did not do so in autistic participants, in line with STORM’s predictions. In the next two studies, I found that non-autistic participants mimicked the movement trajectory of both virtual characters and human actors during an imitation game. Autistic participants also mimicked but did so to a lesser extent. However, this type of mimicry was resistant to the effects of social cues, such as eye-gaze and animacy, contrary to the predictions of STORM. In a fourth study, I manipulated the rationality of an actor’s movement trajectory and found that participants mimicked the trajectory even when the trajectory was rated as irrational. In a fifth study, I showed that people’s tendency to mimic the movements of others could change the choices that participants had previously made in private. This tendency was modulated by the kinematics of the character’s pointing movements. This thesis provides mixed support for STORM’s predictions and I discuss the reasons why this might be. I also make suggestions for how to better measure and modulate mimicry