title: Working memory and reward association learning impairments in obesity.
abstract: Obesity has been associated with impaired executive functions including working memory. Less explored is the influence of obesity on learning and memory. In the current study we assessed stimulus reward association learning, explicit learning and memory and working memory in healthy weight, overweight and obese individuals. Explicit learning and memory did not differ as a function of group. In contrast, working memory was significantly and similarly impaired in both overweight and obese individuals compared to the healthy weight group. In the first reward association learning task the obese, but not healthy weight or overweight participants consistently formed paradoxical preferences for a pattern associated with a negative outcome (fewer food rewards). To determine if the deficit was specific to food reward a second experiment was conducted using money. Consistent with Experiment 1, obese individuals selected the pattern associated with a negative outcome (fewer monetary rewards) more frequently than healthy weight individuals and thus failed to develop a significant preference for the most rewarded patterns as was observed in the healthy weight group. Finally, on a probabilistic learning task, obese compared to healthy weight individuals showed deficits in negative, but not positive outcome learning. Taken together, our results demonstrate deficits in working memory and stimulus reward learning in obesity and suggest that obese individuals are impaired in learning to avoid negative outcomes.
authors.affiliation: The John B. Pierce Laboratory, 290 Congress Avenue, New Haven, CT 06519, USA; Department of Psychiatry, School of Medicine, Yale University, 300 George Street, Suite 901, New Haven, CT 06511, USA. Electronic address: gcoppin@jbpierce.org.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Coppin
authors.affiliation: The John B. Pierce Laboratory, 290 Congress Avenue, New Haven, CT 06519, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Nolan-Poupart
authors.affiliation: Cognitive Neuroscience, Montreal Neurological Institute, 3801 University Street, Montreal, QC, Canada; Department of Psychology, McGill University, Montreal, QC, Canada.
authors.forename: Marilyn
authors.initials: M
authors.lastname: Jones-Gotman
authors.affiliation: The John B. Pierce Laboratory, 290 Congress Avenue, New Haven, CT 06519, USA; Department of Psychiatry, School of Medicine, Yale University, 300 George Street, Suite 901, New Haven, CT 06511, USA. Electronic address: dsmall@jbpierce.org.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Small
mesh_terms: D000328:Adult; D001245:Association Learning / Q000502:physiology*; D015992:Body Mass Index; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009765:Obesity / Q000150:complications*; D050177:Overweight / Q000150:complications*; D012201:Reward; D055815:Young Adult
keywords: Cognitive dysfunction; Conditioning; Explicit memory; Impulsivity; Negative outcome learning; Neuropsychology; Obesity; Working memory