When Emotions Hurt: Reduced Differentiation Between Physiological and Emotional States in Fibromyalgia

People with fibromyalgia often demonstrate hypersensitivity to benign bodily signals and misattribute non-noxious physical signals as pain, suggesting alterations in body-brain communication and interoception. However, little is known about whether altered body-brain communication may extend to misattribution of emotion as pain. Here, using a cross-sectional design, we aimed to investigate how individuals with fibromyalgia perceive, identify, and interpret emotions and other bodily sensations, including pain, compared to healthy controls. Across two independent studies, individuals with fibromyalgia and age- and gender-matched pain-free controls completed the emBODY task, which assesses the topography of bodily sensations experienced for different states (emotional states, neutral state, pain- and physiology-related states, fatigue). Additionally, participants completed assessments of alexithymia, bodily sensation interpretation, and interoception. In both studies, linear discriminant analysis, performedto test whether different emotions and states are associated with statistically distinct bodily patterns, indicated lower classification accuracy of body sensation maps in the fibromyalgia group than in controls. Moreover, compared with controls, the fibromyalgia group showed higher levels of alexithymia, higher awareness of bodily signals, and more negative interpretation of ambiguous bodily sensations in daily life, together with greater self-reported interoceptive difficulties. Our findings support an amplified perception of bodily signals coupled with interoceptive difficulties and poorer differentiation of both emotions and non-emotional states in people with fibromyalgia. This raises the possibility that interventions that targetperceptual retraining, emotional state differentiation, and re-interpretation of bodily sensations might decrease the impact of pain and promote engagement in everyday activities for people with fibromyalgia.