Other people’s internal emotional states can sometimes be perceived through the physical responses they cause. These responses are mimicked, or embodied, by viewers, and this process is believed to aid prediction of other people’s feelings and future actions. We propose that when other people’s emotional expressions are embodied through facial mimicry, these embodiments are reactivated during later encounters, even when the person who was previously emotional now shows no emotionalstate. These embodied retrieval processes might underpin the ability to act predictively of someone’s future state. We also propose that even subtle cues, that are not knowingly perceived, cause long-­‐term changes in the way we represent individuals.Inthe first half of this thesis the reinstatement of facial mimicry effects was investigated. In a series of experiments participants viewed faces that became consistently happy or angry, and later viewed the same faces with neutral expressions. Facial mimicry effects elicited by the faces were shown to be activated predictively of the forthcoming emotion, and in the later task reactivated in response to the neutral faces. These effects only occurred in those participants who first embodied the emotions they saw on the faces, and were shown not to occur for emotional, but non-­‐facial stimuli.In the second half of the thesis, we investigated the potential encoding of pupil size, a very subtle cue to arousal state. We showed that women, but not men, demonstrated encoding and retrieval of other people’s pupil size changes that affected later perceptions of those individuals. This effect was shown even though the
2participants were unaware of observing pupil size changes, and was shown to be modulated by static traits of the faces, and to possibly be underpinned by reinstated physiological responses.Together the experiments in this thesis provide evidence that observers not only embody the physical cues of the emotional states of others, and detect these cueswhen they are very subtle, but that this embodiment and perception at the time of an interaction can be encoded and later recalled, causing lasting changes in the way the observer perceives or responds to an individual.