Obese adults have visual attention bias for food cue images: evidence for altered reward system function.
BACKGROUND
The major aim of this study was to investigate whether the motivational salience of food cues (as reflected by their attention-grabbing properties) differs between obese and normal-weight subjects in a manner consistent with altered reward system function in obesity.


RESULTS
A total of 18 obese and 18 normal-weight, otherwise healthy, adult women between the ages of 18 and 35 participated in an eye-tracking paradigm in combination with a visual probe task. Eye movements and reaction time to food and non-food images were recorded during both fasted and fed conditions in a counterbalanced design. Eating behavior and hunger level were assessed by self-report measures. Obese individuals had higher scores than normal-weight individuals on self-report measures of responsiveness to external food cues and vulnerability to disruptions in control of eating behavior. Both obese and normal-weight individuals demonstrated increased gaze duration for food compared to non-food images in the fasted condition. In the fed condition, however, despite reduced hunger in both groups, obese individuals maintained the increased attention to food images, whereas normal-weight individuals had similar gaze duration for food and non-food images. Additionally, obese individuals had preferential orienting toward food images at the onset of each image. Obese and normal-weight individuals did not differ in reaction time measures in the fasted or fed condition.


CONCLUSIONS
Food cue incentive salience is elevated equally in normal-weight and obese individuals during fasting. Obese individuals retain incentive salience for food cues despite feeding and decreased self-report of hunger. Sensitization to food cues in the environment and their dysregulation in obese individuals may play a role in the development and/or maintenance of obesity.
Castellanos
E H
EH
Psychiatric Neuroimaging Program, Vanderbilt University School of Medicine, Nashville, TN 37212, USA.
Charboneau
E
E
Dietrich
M S
MS
Park
S
S
Bradley
B P
BP
Mogg
K
K
Cowan
R L
RL
D000293:Adolescent; D000328:Adult; D003463:Cues; D005071:Evoked Potentials / Q000502:physiology; D005215:Fasting / Q000523:psychology; D005247:Feeding Behavior / Q000502:physiology / Q000523:psychology*; D005260:Female; D005502:Food; D006801:Humans; D006815:Hunger / Q000502:physiology*; D009765:Obesity / Q000503:physiopathology / Q000523:psychology*; D012201:Reward; D011795:Surveys and Questionnaires; D055815:Young Adult