The cortical representation of pain

Abstract

Anatomical and physiological studies in animals, as well as functional imaging studies in humans have shown that multiple cortical areas are activated by painful stimuli. The view that pain is perceived only as a result of thalamic processing has, therefore, been abandoned, and has been replaced by the question of what functions can be assigned to individual cortical areas. The following cortical areas have been shown to be involved in the processing of painful stimuli: primary somatosensory cortex, secondary somatosensory cortex and its vicinity in the parietal operculum, insula, anterior cingulate cortex and prefrontal cortex. These areas probably process different aspects of pain in parallel. Previous psychophysical research has emphasized the importance of separating pain experience into sensory-discriminative and affective-motivational components. The sensory-discriminative component of pain can be considered a sensory modality similar to vision or olfaction; it becomes more and more evident that it is subserved by its own apparatus up to the cortical level. The affective-motivational component is close to what may be considered 'suffering from pain'; it is clearly related to aspects of emotion, arousal and the programming of behaviour. This dichotomy, however, has turned out to be too simple to explain the functional significance of nociceptive cortical networks. Recent progress in imaging technology has, therefore, provided a new impetus to study the multiple dimensions of pain.

Brain activity associated with painfully hot stimuli applied to the upper limb: A meta‐analysis

“…In addition to terminations in the major homeostatic regions of the brainstem, spinothalamic neurons project to nuclei in medial and ventral posterior lateral regions of the thalamus. An anatomical and functional distinction is made frequently between lateral and medial pain pathways that are constituted by the targets of projections from the respective groups of thalamic nuclei [Treede et al, 1999]. The classic termination of the spinothalamic pathway, the primary somatosensory cortex is synonymous with the lateral pain pathway and has been ascribed with sensory/discriminative functions.…”

Long-term changes in behavior and regional cerebral blood flow associated with painful peripheral mononeuropathy in the rat

“…Kenshalo and Willis (1991) and Treede et al (1999) have recently reviewed the evidence for a role of the cerebral cortex in the perception and control of pain. The numerous PET studies have revealed activity in the human sensorimotor cortex during pain (for reviews, see Bushnell et al, 1999;Casey, 1999).…”

Nociception and autonomic nervous system

“…In humans, most of these studies have relied on non-invasive functional neuroimaging techniques to sample, directly or indirectly the neural activity triggered by various kinds of nociceptive stimuli showing that nociceptive stimuli elicit responses in several subcortical and cortical brain structures [13][14][15][16][17][18][19][20][21]. The responses in some of these structures are observed consistently across studies, and seem to be correlated with the perceived intensity of pain.…”