The sensory-discriminative and affective-motivational aspects of pain

What is the difference between pain and standard exteroceptive perceptual processes, such as vision or audition? According to the most common view, pain constitutes the internal perception of bodily damage. Following on from this definition, pain is just like exteroceptive perception, with the only difference being that it is not oriented toward publicly available objects, but rather toward events that are taking place in/to one's own body. Many theorists, however, have stressed that pain should not be seen as a kind of perception, but rather that it should be seen as a kind of affection or motivation to act instead. Though pain undeniably has a discriminatory aspect, what makes it special is its affective-motivational quality of hurting. In this article, we discuss the relation between pain and perception, at both the conceptual and empirical levels. We first review the ways in which the perception of internal damage differs from the perception of external objects. We then turn to the question of how the affective-motivational dimension of pain is different from the affective-motivational aspects that are present for other perceptual processes. We discuss how these differences between pain and exteroceptive perception can account for the fact that the experience of pain is more subjective than other perceptual experiences. (C) 2008 Elsevier Ltd. All rights reserved.