Psychophysiological reactivity to symptom-related emotional stimuli in insomnia: A replication and extension to disordered eating

The present study examined psychophysiological reactivity to emotional stimuli in people with persistent insomnia alone or comorbid with disordered eating and in healthy controls. Female participants (39) were presented with 5 blocks of stimuli differing for valence (positive, negative or neutral) and for relatedness to the symptoms complied (sleep or food and body shape). Facial EMG over the corrugator and the zygomatic muscles, Heart Rate, Skin Conductance Level and subjective ratings of valence and arousal were recorded. Results confirmed that people complaining of symptoms of persistent insomnia show reduced activation of the corrugator muscle when exposed to positive stimuli related to sleep. This effect, interpreted as craving, was also found in the asymptomatic control group for the stimuli depicting fit bodies or healthy foods. An enhancement of the corrugator activity indicative of a worry effect was found in the healthy control group for negative sleep related stimuli and in the group with a mixed symptomatology for the negative stimuli related to food and body shape.