Functional Organization of Auditory and Reward Systems in Healthy Aging.

The intrinsic organization of functional brain networks is known to change with age, and is affected by perceptual input and task conditions. Here, we compare functional activity and connectivity during music listening and rest between young (N=24) and older (N=24) adults, using whole brain regression, seed-based connectivity, and ROI-ROI connectivity analyses. We found that although auditory and reward regions follow expected patterns of activation in response to music listening across both groups, younger adults show higher within-network connectivity of auditory and reward regions as compared to older adults during both rest and music listening. We also show that this age-related difference was reduced during music listening, especially in individuals showing high self-reported musical reward. Furthermore, young adults showed higher connectivity between auditory network and medial prefrontal cortex (mPFC) that was specific to music listening and varied as a function of liking ratings. Meanwhile, older adults showed a more globally diffuse pattern of connectivity, including higher connectivity to bilateral lingual and inferior frontal gyri. Finally, connectivity between auditory and reward regions was higher during well-liked musical stimuli across all participants, and especially higher when listening to music selected by the participant. These results highlight the roles of aging and reward sensitivity on auditory and reward networks. Results may inform the design of music-based interventions in aging populations, and improve our understanding of functional network dynamics as a whole.