Assessing body image in anorexia nervosa using biometric self-avatars in virtual reality: Attitudinal components rather than visual body size estimation are distorted.

BACKGROUND: Body image disturbance (BID) is a core symptom of anorexia nervosa (AN), but as yet distinctive features of BID are unknown. The present study aimed at disentangling perceptual and attitudinal components of BID in AN. METHODS: We investigated n = 24 women with AN and n = 24 controls. Based on a three-dimensional (3D) body scan, we created realistic virtual 3D bodies (avatars) for each participant that were varied through a range of ±20% of the participants' weights. Avatars were presented in a virtual reality mirror scenario. Using different psychophysical tasks, participants identified and adjusted their actual and their desired body weight. To test for general perceptual biases in estimating body weight, a second experiment investigated perception of weight and shape matched avatars with another identity. RESULTS: Women with AN and controls underestimated their weight, with a trend that women with AN underestimated more. The average desired body of controls had normal weight while the average desired weight of women with AN corresponded to extreme AN (DSM-5). Correlation analyses revealed that desired body weight, but not accuracy of weight estimation, was associated with eating disorder symptoms. In the second experiment, both groups estimated accurately while the most attractive body was similar to Experiment 1. CONCLUSIONS: Our results contradict the widespread assumption that patients with AN overestimate their body weight due to visual distortions. Rather, they illustrate that BID might be driven by distorted attitudes with regard to the desired body. Clinical interventions should aim at helping patients with AN to change their desired weight.

A prototype haptic suturing simulator.

A new haptic simulation designed to teach basic suturing for simple wound closure is described. Needle holders are attached to the haptic device as the graphics of the needle holders, needle, sutures and virtual skin are displayed and updated in real time. The simulator incorporates several interesting components such as real-time modeling of deformable skin, tissue and suture material and real-time recording of state of activity during the task using a finite state model.

A virtual reality surgical trainer for navigation in laparoscopic surgery.

A virtual reality trainer was designed to familiarize students and surgeons with surgical navigation using an angled laparoscopic lens and camera system. Previous laparoscopic trainers have been devoted to task or procedure training. Our system is exclusively devoted to laparoscope manipulation and navigation. Laparoscopic experts scored better than novices in this system suggesting construct validity. The trainer received favorable subjective ratings. This simulator may provide for improved navigation in the operating room and become a useful tool for residents and practicing surgeons.