Does virtual reality enhance the effects of inhibitory control training for loss-of-control eating? A pilot factorial experiment

Inhibitory control, one's ability to inhibit automatic responses to desirable stimuli, may be inadequately targeted in interventions for loss-of-control eating (LOC). Promising evidence has identified inhibitory control trainings (ICTs) as an avenue to target inhibitory control directly; however, effects of ICTs on real-world behavior are limited. Compared to typical computerized trainings, virtual reality (VR) presents several potential advantages that may address key shortcomings of traditional ICTs, i.e. poor approximation to everyday life. The present study utilized a 2 × 2 factorial design of treatment type (ICT vs sham) by treatment modality (VR vs standard computer), which allows for increased statistical power by collapsing across conditions. Our primary aim was to examine the feasibility and acceptability of six weeks of daily training among groups. A secondary aim was to preliminarily assess main and interactive effects of treatment type and modality on target engagement and efficacy (i.e., training compliance, change in LOC episodes, inhibitory control, and implicit liking of foods). Participants (N = 35) with ≥1×/weekly LOC were assigned to one of four conditions and completed ICTs daily for six weeks. The trainings were feasible and acceptable, evinced by high retention and compliance across time and condition. Although completing daily trainings across treatment types and modalities was associated with large decreases in LOC, there were no meaningful effects of either treatment type or modality, nor a significant interaction effect, on LOC or mechanistic variables. Future research should aim to increase the efficacy of ICT (both standard and VR-based) and test in fully-powered clinical trials.