Striatum–Medial Prefrontal Cortex Connectivity Predicts Developmental Changes in Reinforcement Learning

Abstract

During development, children improve in learning from feedback to adapt their behavior. However, it is still unclear which neural mechanisms might underlie these developmental changes. In the current study, we used a reinforcement learning model to investigate neurodevelopmental changes in the representation and processing of learning signals. Sixty-seven healthy volunteers between ages 8 and 22 (children: 8-11 years, adolescents: 13-16 years, and adults: 18-22 years) performed a probabilistic learning task while in a magnetic resonance imaging scanner. The behavioral data demonstrated age differences in learning parameters with a stronger impact of negative feedback on expected value in children. Imaging data revealed that the neural representation of prediction errors was similar across age groups, but functional connectivity between the ventral striatum and the medial prefrontal cortex changed as a function of age. Furthermore, the connectivity strength predicted the tendency to alter expectations after receiving negative feedback. These findings suggest that the underlying mechanisms of developmental changes in learning are not related to differences in the neural representation of learning signals per se but rather in how learning signals are used to guide behavior and expectations.

What motivates adolescents? Neural responses to rewards and their influence on adolescents’ risk taking, learning, and cognitive control

“…More recent studies suggest that developmental differences in response to rewards may not be due to changes in learning signals, but how these learning signals drive subsequent behavior. That is, learning-rates were related to changes in functional connectivity between the striatum and medial PFC (van den Bos et al, 2012). It has been suggested that these findings indicate a greater influence of positive and negative outcomes in adolescents' motivated behavior that are dependent on the interaction between subcortical and cortical neural systems (Hartley and Somerville, 2015).…”

Predictability and context determine differences in conflict monitoring between adolescence and adulthood

“…Previous results suggest that expectancy and prediction effects are modulated by medial frontal areas (e.g. Bermpohl et al, 2006;Chmielewski et al, 2014;Ferdinand and Opitz, 2014;Forster and Brown, 2011;Shenhav et al, 2013;van den Bos et al, 2012). Against this background, it is possible that the well-known protracted medial prefrontal development throughout adolescence impairs prediction and thus hinders the establishment of expectancy effects.…”

“…So if the current trial composes a compatible stimulus-response mapping, participants will expect the same in the next trial. Such expectancy effects during response selection have recently been shown to be modulated by medial frontal areas (Bermpohl et al, 2006;Chmielewski et al, 2014;Ferdinand and Opitz, 2014;Forster and Brown, 2011;Shenhav et al, 2013;van den Bos et al, 2012), which are known to undergo maturational changes between adolescence and adulthood. It is therefore crucial to experimentally manipulate expectancy effects, when investigating the developmental modulation of congruency sequence effects between adolescence and adulthood.…”

Supplemental Material for Charting the Expansion of Strategic Exploratory Behavior During Adolescence

“…Computational modeling analyses (presented in the next section) were tested for age confounds in overall quality of fit, which could preclude interpretation of developmental effects (Hartley & Somerville, 2015;van den Bos et al, 2012).…”