Neural networks involved in adolescent reward processing: An activation likelihood estimation meta-analysis of functional neuroimaging studies

Abstract

Behavioral responses to, and the neural processing of, rewards change dramatically during adolescence and may contribute to observed increases in risk-taking during this developmental period. Functional MRI (fMRI) studies suggest differences between adolescents and adults in neural activation during reward processing, but findings are contradictory, and effects have been found in non-predicted directions. The current study uses an activation likelihood estimation (ALE) approach for quantitative meta-analysis of functional neuroimaging studies to: (1) confirm the network of brain regions involved in adolescents' reward processing, (2) identify regions involved in specific stages (anticipation, outcome) and valence (positive, negative) of reward processing, and (3) identify differences in activation likelihood between adolescent and adult reward-related brain activation. Results reveal a subcortical network of brain regions involved in adolescent reward processing similar to that found in adults with major hubs including the ventral and dorsal striatum, insula, and posterior cingulate cortex (PCC). Contrast analyses find that adolescents exhibit greater likelihood of activation in the insula while processing anticipation relative to outcome and greater likelihood of activation in the putamen and amygdala during outcome relative to anticipation. While processing positive compared to negative valence, adolescents show increased likelihood for activation in the posterior cingulate cortex (PCC) and ventral striatum. Contrasting adolescent reward processing with the existing ALE of adult reward processing reveals increased likelihood for activation in limbic, frontolimbic, and striatal regions in adolescents compared with adults. Unlike adolescents, adults also activate executive control regions of the frontal and parietal lobes. These findings support hypothesized elevations in motivated activity during adolescence.

Figure 1

Brain regions showing likelihood of brain activation in the overall adolescent ALE (top panel), stage analyses (second and third panels) and valence analyses (fourth and fifth panels).

Figure 2

Brain areas with differential activation likelihoods between valence and stage analyses. For anticipation>outcome one significant cluster was found including regions of the left insula and frontal operculum cortex. Cluster locations for outcome>anticipation included the left amygdala and putamen. Cluster locations for positive>negative included the right posterior cingulate gyrus, NAcc, subcallosal cortex, and lateral occipital cortex.

Figure 3

Brain areas showing increased likelihood for activation in adolescents relative to adults. Cluster locations include subcortical regions such as the ventral and dorsal striatum and the amygdala as well as the anterior and posterior cingulate cortex, the orbital frontal cortex, and the lateral occipital cortex.