Characterizing age-related changes in cerebellar BOLD low frequency fluctuations

Motivation: Aging results in cerebellar structural changes and associated behavioral changes, but cerebellar fMRI metrics remain unidentified. Goal(s): Our goal was to detect aging changes using (fractional) Amplitude of Low Frequency Fluctuations ((f)ALFF) in the cerebellum, a structure critical for unconscious learning but often overlooked in fMRI studies. Approach: Resting state fMRI data from the Human Connectome Project Young Adult (YA) and Aging (OA) datasets were used. (f)ALFF maps were normalized to the SUIT atlas. Group-level (f)ALFF differences and their reproducibility was assessed. Results: Cerebellar fALFF is more repeatable than ALFF, but ALFF in anterior regions is significantly higher in YA than OA. Impact: Cerebellar (f)ALFF reveals robust differences between young and older participants. This semi-quantitative, functional metric has potential to characterize healthy aging, which can be used to identify correlations with behavior related to the cerebellar function.