title: Is it Worth the Effort? Novel Insights into Obesity-Associated Alterations in Cost-Benefit Decision-Making.
abstract: Cost-benefit decision-making entails the process of evaluating potential actions according to the trade-off between the expected reward (benefit) and the anticipated effort (costs). Recent research revealed that dopaminergic transmission within the fronto-striatal circuitry strongly modulates cost-benefit decision-making. Alterations within the dopaminergic fronto-striatal system have been associated with obesity, but little is known about cost-benefit decision-making differences in obese compared with lean individuals. With a newly developed experimental task we investigate obesity-associated alterations in cost-benefit decision-making, utilizing physical effort by handgrip-force exertion and both food and non-food rewards. We relate our behavioral findings to alterations in local gray matter volume assessed by structural MRI. Obese compared with lean subjects were less willing to engage in physical effort in particular for high-caloric sweet snack food. Further, self-reported body dissatisfaction negatively correlated with the willingness to invest effort for sweet snacks in obese men. On a structural level, obesity was associated with reductions in gray matter volume in bilateral prefrontal cortex. Nucleus accumbens volume positively correlated with task induced implicit food craving. Our results challenge the common notion that obese individuals are willing to work harder to obtain high-caloric food and emphasize the need for further exploration of the underlying neural mechanisms regarding cost-benefit decision-making differences in obesity.
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany; IFB Adiposity Diseases, Leipzig University Medical CenterLeipzig, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Mathar
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany; IFB Adiposity Diseases, Leipzig University Medical CenterLeipzig, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Horstmann
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany; IFB Adiposity Diseases, Leipzig University Medical CenterLeipzig, Germany; Clinic of Cognitive Neurology, University Hospital LeipzigLeipzig, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Pleger
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany; IFB Adiposity Diseases, Leipzig University Medical CenterLeipzig, Germany; Clinic of Cognitive Neurology, University Hospital LeipzigLeipzig, Germany; Berlin School of Mind and Brain, Mind and Brain Institute, Humboldt-UniversityBerlin, Germany.
authors.forename: Arno
authors.initials: A
authors.lastname: Villringer
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany; IFB Adiposity Diseases, Leipzig University Medical CenterLeipzig, Germany.
authors.forename: Jane
authors.initials: J
authors.lastname: Neumann
keywords: cost-benefit decision-making; obesity; physical effort; reward; voxel-based morphometry