Abstract

Pain is a multidimensional experience comprising sensory, affective and cognitive aspects, and this work concentrates on the cognitive dimension, elaborated as an epistemic function of the whole individual. ;I will outline the problem of pain theories by examining special case. Insensitivity to pain, phantom limb pain, trigeminal neuralgia, and pain psychophysics all show the need for revision of simple sensory models of pain; cases such as neonatal pain, children's pain and childbirth pain also show important variations in the experience of pain. ;Peripheral mechanisms will be examined, and pattern theory will be presented as the outcome of the historical development of pain theories. Microneurography's lessons will be critically examined, and peripheral neuropathies will also highlight the importance of the balance of the afferent barrage. ;Afferent balance will be examined for its importance in segmental actions, including the gate control theory. New developments in segmental circuitry will be proposed, incorporating new discoveries in dorsal laminae projection pools into a philosophical concept stressing the organism's ability to process nociceptive stimuli with respect to the animal's overall ongoing state. The importance of dorsal horn peptides will also be advanced from current laboratory studies. ;Suprasegmental sections will examine the multiplicity of ascending tracts subserving pain perception, and descending mechanisms will be reviewed. Cortical structures will be briefly examined, and a new philosophical analysis of leucotomy will be developed. The complicated and continuously unfolding range of opioid and non-opioid endogenous analgesics will be discussed, and the current range of drugs used against pain will also be examined. ;The latter topic will lead into psychological variables of pain. ;The final proposal will be that pain's cognitive-evaluative dimension shows that pain varies in important ways with the meaning of particular stimuli for the individual. This will explain some kinds of variations of the pain experience, and the key example of the athlete will be proposed as the single clear case of "good pain."