Replication and Refinement of Brain Age Model for Adolescent Development

The discrepancy between chronological age and estimated brain age, known as the brain age gap, may serve as a biomarker to reveal brain development and neuropsychiatric problems. This has motivated many studies focusing on the accurate estimation of brain age using different features and models, of which the generalizability is yet to be tested. In the current study, we tested the replicability of various pre-trained brain age models on the Adolescent Brain Cognitive Development (ABCD) cohort and furthermore proposed a refined model to improve the robustness of prediction within a narrow age range. The direct replication tests for existing brain age models derived from the age range of 8-22 years onto the ABCD participants at baseline (9 to 10 years old) and year-two follow-up (11 to 12 years old) indicate that pre-trained models could capture the overall mean age but failed precisely estimating brain age variation. The refined model, which combined broad prediction of the pre-trained model and granular information of specific age range, achieved the best performance with a mean absolute error of 0.49 and 0.48 years on the baseline and year-two data, respectively. The brain age gap yielded by the refined model showed significant associations with the participants’ information processing speed and verbal comprehension ability on baseline data.

1. INTRODUCTION

As we grow, our brain develops and changes parallelly throughout our life. Extracting insightful information from neuroimaging data underlying brain development has become a widely studied research area recently [1], [2], [3]. An individual’s brain age is referred to as biological age, which cannot be measured directly but can be modeled through neuroimaging data. Brain age models are usually trained with brain magnetic resonance imaging (MRI) or other types of neuroimaging resources from a healthy or typical development population. The brain age gap is computed by the difference between chronological age and estimated brain age.