Unhealthy yet Avoidable-How Cognitive Bias Modification Alters Behavioral and Brain Responses to Food Cues in Individuals with Obesity.

Nora Mehl,Arno Villringer,Filip Morys,Annette Horstmann

doi:10.3390/nu11040874

Abstract

Obesity is associated with automatically approaching problematic stimuli, such as unhealthy food. Cognitive bias modification (CBM) could beneficially impact problematic approach behavior. However, it is unclear which mechanisms are targeted by CBM in obesity. Candidate mechanisms include: (1) altering reward value of food stimuli; and (2) strengthening inhibitory abilities. Thirty-three obese adults completed either CBM or sham training during functional magnetic resonance imaging (fMRI) scanning. CBM consisted of implicit training to approach healthy and avoid unhealthy foods. At baseline, approach tendencies towards food were present in all participants. Avoiding vs. approaching food was associated with higher activity in the right angular gyrus (rAG). CBM resulted in a diminished approach bias towards unhealthy food, decreased activation in the rAG, and increased activation in the anterior cingulate cortex. Relatedly, functional connectivity between the rAG and right superior frontal gyrus increased. Analysis of brain connectivity during rest revealed training-related connectivity changes of the inferior frontal gyrus and bilateral middle frontal gyri. Taken together, CBM strengthens avoidance tendencies when faced with unhealthy foods and alters activity in brain regions underpinning behavioral inhibition.

Highlights

The way we process and react to food cues might play an important role in the development and maintenance of unhealthy eating and obesity
In this study we investigated neural correlates of Cognitive bias modification (CBM) in obesity by applying an approach-avoidance training [8] in obese individuals in the functional magnetic resonance imaging (fMRI) scanner, randomly assigning participants to a training or a sham-training condition
A training form of the avoidance task (AAT) was applied in the fMRI scanner, where half of the participants received training, while the other half underwent sham training

Summary

Introduction

The way we process and react to food cues might play an important role in the development and maintenance of unhealthy eating and obesity It has been observed, for example, that overweight and obese individuals show an attention bias towards food images compared to healthy-weight controls and that obese participants display a food approach bias in comparison to lean participants [1,2,3,4]. The reflective–impulsive model [7], for example, states that during automatic behavior, the fast impulsive system overrules the slower reflective system. The former is hereby guided by previously formed associations—approach positive and avoid negative stimuli—while the latter relies on explicit knowledge [7,8]. The incentive sensitization theory (e.g., [9]) further states that through repeated exposure, a reinforcer

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Conclusion