The Department of Cognitive Science cordially invites you to the public defense of the PhD thesis of
Luke McEllin
INVESTIGATING THE PRODUCTION AND PERCEPTION OF MOVEMENT CUES IN JOINT ACTION
Primary supervisor: Natalie Sebanz
Secondary supervisor: Gunther Knoblich
The movements of those engaged in social interactions are laden with meaning, and reflect a whole host of mental states, including intentions and attitudes towards a co-actor. The aim of this thesis was to investigate how the movements of actors engaged in joint actions provide us with information about their informative intentions, and the interpersonal relations of those interacting with each other. Our first study investigated how actors modulate the kinematics of their actions in order to provide informative cues to co-actors, and demonstrated that actions that are identical instrumentally can have different kinematic signatures depending on the informative intentions of the actor (i.e. the intention to coordinate, or the intention to teach). Our second study set out to investigate whether or not observers are able to use kinematic cues to understand an actor’s informative intentions, and demonstrated that not only can observers detect the presence of informative intentions on the basis of movement cues, but they can also discriminate between different informative intentions. Our third study aimed to investigate how different types of interpersonal synchrony affect third person perception of the relations between two actors, and found that the movement cues reflecting different types of synchrony have a direct effect on our perception of a performance in terms of the affiliation between the performers, and how aesthetically pleasing we find these performances. In the final section of this thesis, our findings are discussed with respect to their implications for theories of direct perception of mental states, as well as their applications to our understanding of teaching and learning, and human robot interaction.