Illusions in the thermo-nociceptive system
What does it mean to experience an illusion of pain? The typical role of pain is to signal when the body is damaged. However, pain illusions in the absence of any risk of tissue damage are common in the normal population. For example, a mix of warm and cold stimuli can be perceived as burning hot, as in the case of the Thermal Grill Illusion. So far, research on thermosensation and pain has largely treated pain illusions as curious quirks of the thermo-nociceptive system, and underplayed the fact that these illusions fundamentally contradict core assumptions of mainstream theories of pain perception. In this project, I propose a new approach to advance our understanding of perceptual inference of pain in humans which challenges these assumptions. Specifically, I will use behavioural and neuroimaging experiments to identify the functional properties, clinical relevance and neural basis of both illusory and veridical pain. First, I will extend innovative behavioural, physiological and neuroimaging protocols to investigate the mechanisms underlying pain illusions. Next, I will investigate the clinical relevance of illusory pain, with the ultimate goal of providing novel tools that can offer a mechanistic approach to pain assessment. Finally, I will validate a comprehensive computational model of pain, which can explain both illusory and veridical thermo-nociceptive phenomena in a unified framework. Overall this project will harness pain illusions to uncover general principles of temperature and pain perception, and will validate novel computational techniques for characterising the neural encoding of thermosensation and pain. These outcomes will redefine our understanding of illusory pain and offer new insights into mechanisms of temperature and pain perception in humans.