The observation and experience of actions, emotions, touch, and pain activates overlapping cortical regions. However, the aetiology and function of these so-called “mirrored” representations is unclear. By focusing on the effects of viewing others in pain, this thesis extends our understanding of both the underlying mechanisms and behavioural consequences of vicarious cortical activity. We used multi-voxel pattern analysis to explore whether the type of viewed pain, for example stinging or stabbing pain, was represented by the observer. Our findings demonstrate that only the general experience of pain, rather than the precise sensory consequences of an action, can be accurately identified in regions outside of visual cortex. We predicted that viewing others in pain goes beyond cortical representation, to selective behaviour change in the observer. In a series of experiments, participants viewed a hand either grasp, or avoid, objects that were potentially painful or not painful, whilst detecting tactile stimulation delivered to their right index finger. Participants were faster and more biased to report touch on their own body when viewing someone else in pain. Two further control experiments demonstrated that the “painful grasp effect” was both sensory specific, and could not be explained by attentional effects. These data suggest that shared representations of pain enable the prediction of the sensory consequences of a painful grasp, leading to potentially adaptive behaviour change in the observer. Interestingly, the effects of viewing others in pain are not automatic, but are mediated by tasks demands and relevance of the stimuli to self. Only when participants made judgements about the appropriateness of an action (engaging self referential thought), or viewed the actions from a first person perspective, was the “painful grasp effect” revealed. In contrast to understanding the actions of others, our data support a system that utilises one’s own motor repertoire to represent actions similar to, or relevant to, self.