Effects of exposure to food images on physiological reactivity and emotional responses in women with bulimia nervosa.

BACKGROUND The aim of this study is to compare the effectiveness of two exposure procedures on habituation of emotional responses to food stimuli: (a) exposure to external cues (food images) without eating forbidden food (CE) and (b) exposure to external cues eating forbidden food (with purge prevention). The influence of craving-trait and mood state on the habituation process is also studied. METHOD Emotional modulation of the defense startle reflex was assessed in 26 women at risk of bulimia nervosa. After four exposure trials, changes in the following variables were measured: (a) food craving-state; (b) physiological measures: hearth rate (HR) and skin conductance response (SCR); (c) motivational patterns towards food (defense startle response); and (d) valence, arousal and dominance of the emotional response to food images. RESULTS After treatment, subjects tended to show non-significant lower SCR and heart orientation responses (vs. defense responses); defense startle response was also significantly lower. CONCLUSIONS The exposure procedure, the induced emotional state and the number of exposure trials are analyzed.