Examining cognitive bias modification interventions for reducing food value and choice: Two pre-registered, online studies

There is considerable interest in Cognitive Bias Modification (CBM) as a potential treatment for overweight/obesity. Inhibitory Control Training (ICT: also known as motor response training) and Evaluative Conditioning (EC) are two popular paradigms which rely on associatively learned responses (unhealthy food - > inhibition, or unhealthy food- > negative stimulus, respectively) through repeated cue-response contingencies. Both ICT and EC have demonstrated some effectiveness for reducing food intake, value and/or choice, when administered in the laboratory and online. However, studies have been criticised for inconsistencies in design (e.g. use of inadequate control groups) which makes it difficult to draw robust conclusions. In two pre-registered, online studies our aim was to examine active ICT (study 1: N = 170) and EC (study 2: N = 300) in multiple groups where the cue- > response contingencies were systematically varied (100%, 75%, 50%, 25%), before examining food-cue valuations and hypothetical food choice. In both studies varying the cue- > response contingencies did not lead to significant changes in food-cue devaluation following training. ICT did not substantially influence hypothetical food choice, whereas there was weak evidence that EC reduced choice for unhealthy foods, compared to a control group with 50% cue-response contingencies. Taken together both studies provide limited evidence for online CBM as a viable psychological treatment – at least through the mechanism of food-cue devaluation or changes in healthy and unhealthy food choice. Future research is needed to investigate the factors that contribute towards successful CBM training to critically evaluate the potential for these strategies within interventions.