title: Poor ability to resist tempting calorie rich food is linked to altered balance between neural systems involved in urge and self-control.
abstract: BACKGROUND
  The loss of self-control or inability to resist tempting/rewarding foods, and the development of less healthful eating habits may be explained by three key neural systems: (1) a hyper-functioning striatum system driven by external rewarding cues; (2) a hypo-functioning decision-making and impulse control system; and (3) an altered insula system involved in the translation of homeostatic and interoceptive signals into self-awareness and what may be subjectively experienced as a feeling.
  
  
  METHODS
  The present study examined the activity within two of these neural systems when subjects were exposed to images of high-calorie versus low-calorie foods using functional magnetic resonance imaging (fMRI), and related this activity to dietary intake, assessed by 24-hour recall. Thirty youth (mean BMI = 23.1 kg/m2, range = 19.1 - 33.7; age =19.7 years, range = 14 - 22) were scanned using fMRI while performing food-specific go/nogo tasks.
  
  
  RESULTS
  Behaviorally, participants more readily pressed a response button when go trials consisted of high-calorie food cues (HGo task) and less readily pressed the response button when go trials consisted of low-calorie food cues (LGo task). This habitual response to high-calorie food cues was greater for individuals with higher BMI and individuals who reportedly consume more high-calorie foods. Response inhibition to the high-calorie food cues was most difficult for individuals with a higher BMI and individuals who reportedly consume more high-calorie foods. fMRI results confirmed our hypotheses that (1) the "habitual" system (right striatum) was more activated in response to high-calorie food cues during the go trials than low-calorie food go trials, and its activity correlated with participants' BMI, as well as their consumption of high-calorie foods; (2) the prefrontal system was more active in nogo trials than go trials, and this activity was inversely correlated with BMI and high-calorie food consumption.
  
  
  CONCLUSIONS
  Using a cross-sectional design, our findings help increase understanding of the neural basis of one's loss of ability to self-control when faced with tempting food cues. Though the design does not permit inferences regarding whether the inhibitory control deficits and hyper-responsivity of reward regions are individual vulnerability factors for overeating, or the results of habitual overeating.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: He
authors.forename: Lin
authors.initials: L
authors.lastname: Xiao
authors.forename: Gui
authors.initials: G
authors.lastname: Xue
authors.forename: Savio
authors.initials: S
authors.lastname: Wong
authors.forename: Susan L
authors.initials: SL
authors.lastname: Ames
authors.forename: Susan M
authors.initials: SM
authors.lastname: Schembre
authors.affiliation: Brain and Creativity Institute and Department of Psychology, University of Southern California, Los Angeles, CA, USA. bechara@usc.edu.
authors.forename: Antoine
authors.initials: A
authors.lastname: Bechara
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003463:Cues; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D015438:Health Behavior; D006801:Humans; D007175:Impulsive Behavior; D008279:Magnetic Resonance Imaging; D008297:Male; D009765:Obesity / Q000178:diet therapy; D012201:Reward; D055815:Young Adult