Virtual reality assessment of a high-calorie food bias: Replication and food-specificity in healthy participants

Background: Theoretical models and behavioural studies indicate faster approach behaviour for high-calorie food (approach bias) among healthy participants. A previous study with Virtual Reality (VR) and online motioncapture quantified this approach bias towards food and non-food cues in a controlled VR environment with hand movements. The aim of this study was to test the specificity of a manual approach bias for high-calorie food in grasp movements compared to low-calorie food and neutral objects of different complexity, namely, simple balls and geometrically more complex office tools. Methods: In a VR setting, healthy participants (N = 27) repeatedly grasped or pushed high-calorie food, lowcalorie food, balls and office tools in randomized order with 30 item repetitions. All objects were rated for valence and arousal. Results: High-calorie food was less attractive and more arousing in subjective ratings than low-calorie food and neutral objects. Movement onset was faster for high-calorie food in push-trials, but overall push responses were comparable. In contrast, responses to high-calorie food relative to low-calorie food and to control objects were faster in grasp trials for later stages of interaction (grasp and collect). Non-parametric tests confirmed an approach bias for high-calorie food. Conclusion: A behavioural bias for food was specific to high-calorie food objects. The results confirm the presence of bottom-up advantages in motor-cognitive behaviour for high-calorie food in a non-clinical population. More systematic variations of object fidelity and in clinical populations are outstanding. The utility of VR in assessing approach behaviour is confirmed in this study by exploring manual interactions in a controlled environment.