title: An fMRI study exploring the overlap and differences between neural representations of physical and recalled pain.
abstract: Implementing a recall paradigm without hypnosis, we use functional MRI (fMRI) to explore and compare nociceptive and centrally-driven pain experiences. We posit that a trace of a recent nociceptive event can be used to create sensory-re-experiencing of pain that can be qualified in terms of intensity and vividness. Fifteen healthy volunteers received three levels of thermal stimuli (warm, low pain and high pain) and subsequently were asked to recall and then rate this experience. Neuroimaging results reveal that recalling a previous sensory experience activates an extensive network of classical pain processing structures except the contralateral posterior insular cortex. Nociceptive-specific activation of this structure and the rated intensity difference between physical and recalled pain events allow us to investigate the link between the quality of the original nociceptive stimulus and the mental trace, as well as the differences between the accompanying neural responses. Additionally, by incorporating the behavioural ratings, we explored which brain regions were separately responsible for generating either an accurate or vivid recall of the physical experience. Together, these observations further our understanding of centrally-mediated pain experiences and pain memory as well as the potential relevance of these factors in the maintenance of chronic pain.
authors.affiliation: Nuffield Division Anaesthetics, Nuffield Department Clinical Neurosciences, Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, Oxford, England, United Kingdom. fairhurst@mpg.cbs.de
authors.forename: Merle
authors.initials: M
authors.lastname: Fairhurst
authors.forename: Katherine
authors.initials: K
authors.lastname: Fairhurst
authors.forename: Chantal
authors.initials: C
authors.lastname: Berna
authors.forename: Irene
authors.initials: I
authors.lastname: Tracey
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology; D010147:Pain Measurement / Q000379:methods / Q000523:psychology; D058748:Pain Perception / Q000502:physiology*; D017288:Pain Threshold / Q000502:physiology / Q000523:psychology; D010364:Pattern Recognition, Visual / Q000502:physiology; D010812:Physical Stimulation; D011601:Psychophysics / Q000379:methods; D013003:Somatosensory Cortex / Q000502:physiology; D013696:Temperature; D013997:Time Factors; D055815:Young Adult