Rising levels of overweight pose an increasing burden on healthcare systems worldwide. This is partly due to the fact that unhealthy foods are often appetizing and thus hard to resist, despite knowledge about their detrimental effects on health. The psychological processes underlying choices between immediately rewarding but health-harming and potentially less rewarding but health-promoting options have been described in dual-process models such as the Reflective-Impulsive Model.
These models assume two interacting kinds of processes: one impulsive, association-based, fast, and effortless; the other reflective, based on syllogistic reasoning, slow, and dependent on cognitive resources. While most interventions on eating behavior aim to alter reflective reasoning and increase its influence on behavior, some relatively new computer-based interventions aim to directly change implicit aspects of food intake. They do so by presenting users images of unhealthy food while asking them to show a behavior that is inconsistent with their impulse to approach, i.e. inhibit a response or show an avoidance reaction. This way, the association between unhealthy foods and approach behavior is broken up, reducing the strength of elicited impulses in the future. Evidence has mounted that particularly the Go/No-Go task can reduce intake of unhealthy foods. In this task, participants always need to inhibit their impulse to react when seeing unhealthy food images, creating an “unhealthy-stop” association.
Two important questions have remained unanswered in this research line: (1) What are the psychological mechanisms of behavioral effects in these interventions? (2) How well do laboratory-based demonstrations of efficacy translate to real-world behavior change? This PhD project aims to produce evidence that helps answer those questions and enhance understanding of implicit process interventions by (1) meta-analyzing the scientific literature with a specific focus on implicit bias change as a potential psychological mechanism (Study I), (2) examining a potential neural marker of the psychological mechanisms involved (Study II), and (3) investigating relevant aspects of such an intervention in the field (Study III)