Persistent avoidance of virtual food in anorexia nervosa-restrictive type: Results from motion tracking in a virtual stopping task.

OBJECTIVE: Food avoidance is central to patients with anorexia nervosa-restrictive type (AN-R). Competing accounts in experimental psychopathology research suggest that food avoidance may result from automatic, habitual responses or from elevated inhibitory control abilities. This study investigated behavioral trajectories of food avoidance in a novel virtual reality stopping task. METHOD: Sixty patients with AN-R and 29 healthy controls with normal weight were investigated using a novel, kinematic task in virtual reality. We recorded spatial displacement in stop- and go-trials to virtual food and control objects. Inhibitory control abilities were operationalized by the VR task in stopping performance (i.e., interrupted movement in stop-trials), whereas we also measured habitual avoidance of virtual food across both go- and stop-trials (i.e., delayed movement relative to nonfood objects). RESULTS: In patients with AN-R, hand displacements were shorter to food versus nonfood across stop- and go-trials, reflected in a Stimulus × Group interaction. Healthy controls showed no differences. Importantly, the food-specific effect in AN-R was identical across stop- and go-trials, indicating habitual food avoidance. Moreover, stop error rates (i.e., stop-trials with response) were lower in patients with AN-R. DISCUSSION: The findings suggest food-specific habitual avoidance and heightened generalized inhibitory control in AN-R. The continuously delayed displacements during active hand movements across stop- and go-trials indicated the persistence of patients' avoidance of food. PUBLIC SIGNIFICANCE: Experimental research investigates the mechanisms underlying mental disorders such as anorexia nervosa. In this study, we measured interrupted hand movements in response to food pictures or neutral pictures (shoes) in patients with anorexia nervosa and healthy controls. A virtual reality scenario was used. Findings indicated that patients were slower at approaching food, interrupted or not. Key mechanisms of food avoidance can be translated into habit-based treatment options in future research.

Food-related aversion in a female sample of people with anorexia nervosa: Cognitive-behavioural correlates, somatic and subjective anxiety, and early experiences.

OBJECTIVE: Food-related anxiety and avoidance are key features of anorexia nervosa, and among the most arduous maintaining processes to address in treatment. This study gathered information on the behavioural and cognitive correlates of food-related anxiety, including their associations with early experiences of aversive learning related to food, and more general anxiety. METHODS: One-hundred and forty-four patients with anorexia nervosa were recruited from clinical services in Italy. They completed online questionnaires to assess food-related anxiety, eating disorder psychopathology, eating disorder safety behaviours and threat cognitions, early experience of aversive learning related to food, and somatic anxiety. RESULTS: Experiences of food-related aversive learning were recalled by the majority of the sample (87.86%), with negative psychological consequences following eating being the most often reported (75%). Safety behaviours and threat cognitions related to the consequences of eating were also reported (14.29%-87.86%, and 36.43-90% respectively, depending on the behaviour/cognition). Eating disorder psychopathology was predicted by both somatic anxiety and negative psychological consequences following eating, whereas self-reported food anxiety was only predicted by somatic anxiety. CONCLUSION: Findings validate an anxiety-based model of anorexia nervosa which establishes the role of safety behaviours, threat cognitions, early aversive learning experiences, and anxiety in the psychopathology of the illness. Exposure-based interventions have the potential to target these factors, and inhibit food-related fear.