Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, United Kingdom; Institute for Mental Health, School of Psychology, University of Birmingham, Birmingham, United Kingdom; Centre for Developmental Science, School of Psychology, University of Birmingham, Birmingham, United Kingdom; Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
Charité – Universitätsmedizin Berlin, Institute of Medical Psychology, Berlin, Germany; Max Planck School of Cognition, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
Charité – Universitätsmedizin Berlin, Institute of Medical Psychology, Berlin, Germany; Center for Safe & Healthy Children, The Pennsylvania State University, University Park, United States
The hippocampal-dependent memory system and striatal-dependent memory system modulate reinforcement learning depending on feedback timing in adults, but their contributions during development remain unclear. In a 2-year longitudinal study, 6-to-7-year-old children performed a reinforcement learning task in which they received feedback immediately or with a short delay following their response. Children’s learning was found to be sensitive to feedback timing modulations in their reaction time and inverse temperature parameter, which quantifies value-guided decision-making. They showed longitudinal improvements towards more optimal value-based learning, and their hippocampal volume showed protracted maturation. Better delayed model-derived learning covaried with larger hippocampal volume longitudinally, in line with the adult literature. In contrast, a larger striatal volume in children was associated with both better immediate and delayed model-derived learning longitudinally. These findings show, for the first time, an early hippocampal contribution to the dynamic development of reinforcement learning in middle childhood, with neurally less differentiated and more cooperative memory systems than in adults.
