This dissertation presents three experiments designed to demonstrate the effects of cognitive, emotional and psychosocial factors on pain perception in humans and to identify potential neuroanatomical substrates of attentional and emotional pain modulation. / The first two chapters provide an introduction, including the statement of the rationale and objectives of this Ph.D. project (Chapter 1) and an overview of the relevant background literature (Chapter 2). / Chapter 3 presents a voxel-based morphometry study on the neural correlates of attentional and emotional pain modulation. In agreement with the observation that manipulations of emotion and attention differentially affect pain perception, the results of this experiment suggest that separate neuroanatomical substrates may underlie these pain modulations: the right lateral orbitofrontal, left medial prefrontal, and bilateral entorhinal cortices appear to be implicated in emotional pain modulation, while the right putamen appears to be involved in attentional pain modulation. / The study described in Chapter 4 shows that the experimental manipulation of mood using emotionally-laden visual stimuli preferentially alters pain unpleasantness, leaving pain intensity unaffected. This study replicates the psychophysical observations presented in the study of Chapter 3 (and in previous reports), which used odors to manipulate emotional state, therefore suggesting the independence of this phenomenon from the mood induction technique employed. / The study in Chapter 5 shows that empathy has an effect on pain perception as well, which cannot be explained by mood effects. Participants for whom a state of high empathy was evoked rated painful stimuli applied to themselves as more intense and unpleasant than did those in a state of low empathy; furthermore, the state empathy ratings correlated with the pain ratings. / By showing that emotional state, attention and empathy can influence pain perception, the work in this thesis provides evidence demonstrating that the pain experience can be significantly molded by top-down factors, and is therefore far from being solely determined by the physical properties of the noxious stimulation. These observations might partially explain why the pain response in certain situations appears disproportionately large, or surprisingly small, in relation to the noxious stimulation, and support the utility of psychological methods in the management of pain symptoms.

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