Background and Aims. Complex Regional Pain Syndrome (CRPS) is a disabling chronic pain condition, characterised by symptoms such as allodynia and vasomotor, motor and trophic abnormalities. Typically, CRPS patients present with distorted body representations, which is thought to contribute to the condition’s aetiology (Haggard et al., 2013). However, it is not clear what deficits, if any, exist in the neuropsychological process of updating body representations for this population, and how this might relate to CRPS symptoms. We are studying CRPS patients’ abilities to update their body representation, and its association with physical symptoms. Methods. The process of updating one’s body representation can be studied by measuring changes in visual-tactile interference due to tool use. This process is quantified by the altered cross-modal interference pattern, measured in ms and error rates, following active tool use. Specifically, when tools are crossed, a change occurs whereby distractors cause a greater delay in reaction times and increase error rates when they appear on the same tool rather than in the same visual field. This change indicates that the body representation has updated. Some CRPS symptoms appear to be spatially defined (Moseley, Gallace, Di Pietro, Spence & Iannetti, 2013). Therefore, a secondary outcome is temperature change in the affected limb when the tool crosses the body midline, as a function of the updated body representation. This would indicate a reduction of symptoms. Temperature will be measured using a thermal imaging camera (FLIR T620) with a thermal sensitivity of <0.04C. Consequently, 20 CRPS patients and 20 age matched controls will be recruited. The project has been approved by the University of Bath and NHS ethics committees. Results. CRPS patients are expected to be slower at updating their body representation and/or do so to a lesser extent, as evidenced by patterns of cross-modal interference that differ from those of the controls. Furthermore, an increase in temperature (a reduction in symptoms) of the affected limb, relative to the unaffected one, is expected when the body representation is updated to include the tool, and this is held so that it crosses the body midline. Conclusion. The current study expects to show that CRPS patients have an impaired ability to update their body representation which should correlate with alterations of physical symptoms. This would support the notion that neuropsychological processing underlies many CRPS symptoms. Support by the GW4 BioMed Medical Research Council Doctoral Training Partnership.