Linear and nonlinear age effects of CBF-ALFF were flexibly modeled within a generalized additive model at each vertex, while controlling for sex and in-scanner motion; multiple comparisons were controlled using the false discovery rate (Q < 0.05).
(A) Mean cortical CBF-ALFF coupling declines with age in a nonlinear fashion (F3,828 = 60.0, p < 0.0001). Data points represent the mean CBF-ALFF coupling (Z) for each subject (n = 831) across all vertices that met statistical correction (pfdr < 0.05).
(B) Vertex-level CBF-ALFF declines were prominent in the posterior temporal cortex, parietal cortex, and dorsolateral prefrontal cortex. Partial correlation coefficients (r2) are displayed to show the strength of effects.
(C) Spin testing revealed enrichment of age effects within the dorsal attention network (p = 0.027). The asterisk represents statistical significance. Black bars represent the observed values, whereas the violin plots reflect the null distributions.