Department of Neurology, Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany; International Max Planck Research School NeuroCom, Leipzig, Germany
Hendrik Hartmann
Department of Neurology, Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany; Collaborative Research Centre 1052, University of Leipzig, Leipzig, Germany; Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
Lieneke Katharina Janssen
Department of Neurology, Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany; Institute of Psychology, Otto von Guericke University Magdeburg, Magdeburg, Germany
Department of Neurology, Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany; Department of Child and Adolescent Psychiatry, University of Würzburg, Würzburg, Germany
Department of Child and Adolescent Psychiatry, University of Würzburg, Würzburg, Germany; Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany
Sean Fallon
School of Psychology, University of Plymouth, Plymouth, United Kingdom
Arno Villringer
Department of Neurology, Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany
Annette Horstmann
Department of Neurology, Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, Germany; Collaborative Research Centre 1052, University of Leipzig, Leipzig, Germany; Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
Everyday life requires an adaptive balance between distraction-resistant maintenance of information and the flexibility to update this information when needed. These opposing mechanisms are proposed to be balanced through a working memory gating mechanism. Prior research indicates that obesity may elevate the risk of working memory deficits, yet the underlying mechanisms remain elusive. Dopaminergic alterations have emerged as a potential mediator. However, current models suggest these alterations should only shift the balance in working memory tasks, not produce overall deficits. The empirical support for this notion is currently lacking, however. To address this gap, we pooled data from three studies (N = 320) where participants performed a working memory gating task. Higher BMI was associated with overall poorer working memory, irrespective of whether there was a need to maintain or update information. However, when participants, in addition to BMI level, were categorized based on certain putative dopamine-signaling characteristics (single-nucleotide polymorphisms [SNPs]; specifically, Taq1A and DARPP-32), distinct working memory gating effects emerged. These SNPs, primarily associated with striatal dopamine transmission, appear to be linked with differences in updating, specifically, among high-BMI individuals. Moreover, blood amino acid ratio, which indicates central dopamine synthesis capacity, combined with BMI shifted the balance between distractor-resistant maintenance and updating. These findings suggest that both dopamine-dependent and dopamine-independent cognitive effects exist in obesity. Understanding these effects is crucial if we aim to modify maladaptive cognitive profiles in individuals with obesity.
