RESUMO
BACKGROUND: Attentional bias towards food related stimuli has been proposed as a potential target for dieting intervention, however the evidence supporting a relationship between attentional bias and food intake is mixed. Theory holds that food related attentional bias should be positively associated with measures of stimulus-controlled eating, and that implicit processes such as impulsivity moderate this association. The aim of the present study was to examine whether the proposed relationship between food-related attentional bias and stimulus control exists, and whether it is moderated by impulsivity. METHOD: A community sample of 68 participants completed a food-related attentional bias task and impulsiveness scale during a laboratory visit, after which they recorded their real-world eating in real-time over 14 days using Ecological Momentary Assessment (EMA). During this time, participants also responded to 4-5 randomly timed assessments per day. Food outlet presence (e.g., fast food restaurants, cafes, corner stores etc.) was assessed during both eating and non-eating assessments. EMA data was then used to determine levels of stimulus controlled eating for each participant. FINDINGS: Substantial variation was seen in both our measure of both food-related attentional bias (Range: 33.9 to 80.0) and in the degree to which the participant's eating could be categorised as being under stimulus control (Range: 0.50 to 0.93). However, food-related attentional bias scores were not a significant independent predictor of stimulus control and nor was this relationship moderated by impulsivity. CONCLUSION: Contrary to theoretical predictions, we found no evidence that of an association between attentional bias, impulsivity, and stimulus control. More work is needed to better understand the implicit processes underlying eating behaviour in the real-world.
RESUMO
Objective: Food-related attentional bias has been defined as the tendency to give preferential attention to food-related stimuli. Attentional bias is of interest as studies have found that increased attentional bias is associated with obesity; others, however, have not. A possible reason for mixed results may be that there is no agreed upon measure of attentional bias: studies differ in both measurement and scoring of attentional bias. Additionally, little is known about the stability of attentional bias over time. The present study aims to compare attentional bias measures generated from commonly used attentional bias tasks and scoring protocols, and to test re-test reliability. Methods: As part of a larger study, 69 participants (67% female) completed two food-related visual probe tasks at baseline: lexical (words as stimuli), and pictorial (pictures as stimuli). Reaction time bias scores (attentional bias scores) for each task were calculated in three different ways: by subtracting the reaction times for the trials where probes replaced (1) neutral stimuli from the trials where the probes replaced all food stimuli, (2) neutral stimuli from the trials where probes replaced high caloric food stimuli, and (3) neutral stimuli from low caloric food stimuli. This resulted in three separate attentional bias scores for each task. These reaction time results were then correlated. The pictorial visual probe task was administered a second time 14-days later to assess test-retest reliability. Results: Regardless of the scoring use, lexical attentional bias scores were minimal, suggesting minimal attentional bias. Pictorial task attentional bias scores were larger, suggesting greater attentional bias. The correlation between the various scores was relatively small (r = 0.13-0.20). Similarly, test-retest reliability for the pictorial task was poor regardless of how the test was scored (r = 0.20-0.41). Conclusion: These results suggest that at least some of the variation in findings across attentional bias studies could be due to differences in the way that attentional bias is measured. Future research may benefit from either combining eye-tracking measurements in addition to reaction times.
