Pain is a remarkably complex and a multifaceted process, involving the interaction between physiological and psychological factors in unique ways. Among many other factors, the size of the affected surface area contributes to the pain experience, altering one’s pain perception. Spatial summation is the term used to describe this phenomenon, and is characterized by an increase in pain perception, or a decrease in pain threshold, when the affected surface area is increased. This project investigated the neuronal processes underlying spatial summation of heat sensations in healthy female volunteers, by means of functional magnetic resonance imaging (fMRI) of the central nervous system. The first study of this project involved increasing the surface area of skin stimulated by manipulating the number of thermal probes delivering thermal stimulation, which was delivered just below participants’ measured pain threshold. Surface area was increased on one hand and across two hands to determine the extent of spatial summation, and furthermore, to determine the effect on neural activity in the spinal cord and brainstem. The second study of this project involved increasing the surface area of skin stimulated by a noxious heat stimulus and its effect on pain perception and corresponding neural activity in the spinal cord, brainstem, and brain. Results from this project suggest that the central mechanisms contributing to the spatial summation of heat sensations involve many of many of the brainstem and brain regions involved in processing the emotional, motivational, and cognitive aspects of pain. Therefore, increasing the surface area of stimulation may alter pain perception by influencing the affective dimension of the sensation, rather than the sensory/discriminatory component. The combination of such structures may interact in a unique way to protect the body from potential, or further damage, by increasing the perception of pain through emotional, motivational and cognitive mechanisms. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2013-07-15 19:01:37.694
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/8130 |
| Date | 29 July 2013 |
| Creators | Beynon, MICHAELA |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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