Thesis defense Marlene Meyer (Donders Series 151)

2 April 2014

Promotor: Prof.dr. H. Bekkering, copromotor: Dr. S. Hunnius

The developing brain in action. Individual and joint action processing

From early in life children are eager to interact with their environment, be it toys, their own little feet or other people around them. Despite their eager involvement in interactions, infants and young children still face difficulties in successfully carrying out goal-directed actions with objects and in coordination with others. Learning how to act and interact successfully in the world involves several neurocognitive processes such as planning, controlling and monitoring one’s own actions, as well as predicting and monitoring others’ actions.

With a focus on early childhood, we set out to investigate the development of individual and joint actions and each of the processes involved.

We found that well-coordinated joint action in a turn-taking context emerges at the end of the third year of life (Chapter 1). In particular, the ability to precisely predict another person’s actions was related to the timing of actions during the joint coordination in young children. The ability to control the own actions was related to the children’s ability to maintain the joint turn-taking structure (Chapter 4). Furthermore, 3-year-old children showed differential motor activity in monitoring the actions of another person, dependent on the child’s involvement in a joint action with that person (Chapter 3). Our findings with adults suggest that higher-order action planning can emerge in both individual and joint actions. Learning to adjust action planning over time was not only observed in individual and joint actions separately but transferred from individual to joint actions (Chapter 2). The outcomes of the last two studies shifted focus from insights on successful and well-coordinated actions to the processing of erroneous actions. Neural correlates of feedback monitoring and feedback-learning were evident in toddlers below the age of three (Chapter 5). Moreover, findings suggest that motor development plays an important role in evaluating successful and erroneous actions of others (Chapter 6).

One conclusion that can be drawn from the convergent evidence (presented in Chapters 1, 3 & 4) is that the emergence of well-coordinated joint action in toddlers is tied closely to them using their own neural motor system to predict and monitor others’ actions. Moreover, young children’s inhibitory control and feedback monitoring (both previously related to prefrontal brain regions) is associated to enhanced individual (Chapter 5) and joint action (Chapter 4) performance.