Abstract ICON Biased affective ratings and reduced electrodermal responses in women with fibromyalgia Jennifer Héraut, MSc., Khira El Bouragui, PhD, Alice Bodart, MSc., Laurent Lefebvre, PhD, Mandy Rossignol, PhD Cognitive psychology and neuropsychology department. University of Mons, Belgium. Corresponding author: Mandy.Rossignol@umons.ac.be Objective: To evaluate the relationship between electrodermal response and emotional appraisal of tactile and visual stimuli in women with fibromyalgia as compared to healthy controls. Research question: Fibromyalgia syndrome (FMS) is a chronic disorder characterized by widespread musculoskeletal pain, fatigue and mood issues. The central sensitization theory postulates that pain in FMS comes from an abnormal processing of sensory impulses. However, altered emotional appraisal may also contribute to complains in FMS. This study aimed to evaluate whether FMS disturbs subjective appraisal and electrodermal activity in response to neutral and emotional pictures, and to non-painful tactile stimuli. Methods: 22 women (Mean age = 45.86; SD = 12.03) diagnosed with FMS and 20 healthy control (HC) women paired on age and education took part to the experiment. Participants completed the Beck Depression Inventory - 13 items before to complete the experimental task consisting to appraise 45 positive, negative and neutral pictures from the IAPS and eight tactile stimulations (two for each of the four categories - tact, pressure, temperature, vibration). After each stimulus, participants had to provide an evaluation using the Self-Assessment Manikin (SAM) on three dimensions: valence, arousal and dominance. Moreover, electrodermal activity (EDA) was monitored during the entire experience. Results: First, EDA did not differ between groups for visual stimuli, but FMS women evaluated positive pictures more negatively than HC. Second, FMS women produced reduced EDA for tactile stimuli as compared to HC, without group difference on the subjective appraisal of these stimuli Finally, FMS patients showed greater levels of depression than HC and, in the complete sample, depression score was correlated to reduced EDA responses for visual and tactile stimuli. Conclusions: First, we suggest that deficits in subjective appraisal and EDA responses were not associated in FMS, since EDA reduction appears for tactile stimuli without modification of subjective appraisal, while the reverse was observed for positive visual stimuli. Second, depression may mediate the reduction of EDA in response to visual stimuli and increases the affective disturbances in these patients. Our results suggest a dissociation between physiological responses and subjective evaluation of external stimuli in FMS, as well as a need to distinguish effects due to FMS from those linked to low mood and depressive affects. Poster or Open Paper Keywords: Fibromyalgia, emotion, emotional rating electrodermal activity, IAPS.