Neurobehavioural representations of observed action viewpoint

Abstract

This thesis examined whether the viewpoint from which an action was observed could modulate the behavioural and neural activity of the observer. Chapter 2 presents motion capture data from a manual prehension task which manipulated observed reach height. Actions were observed from two allocentric viewpoints. The data revealed no differences between viewpoints, but did reveal effects of relative spatial direction congruency. Chapter 3 further examined these direction congruency effects. Using simple arm movements, observed task and direction congruency were split. The data revealed effects of direction congruency dependent on observed action viewpoint. Chapter 4 presents experiments further examining the effects of observed action viewpoint. The data suggest participants considered observed actions in terms of agency; participants responded faster when observing egocentrically framed actions compared to allocentrically framed actions. Chapter 5 further examined this using functional Magnetic Resonance Imaging. The data suggest that stronger representations of observed actions are present for egocentric actions compared to allocentric actions. Collectively, this thesis demonstrates that relative spatial direction kinematics are a key factor in action observation, and that the viewpoint from which an action is observed can modulate participant behavioural responses and brain activity, as participants distinguish between egocentrically and allocentrically framed actions