Fig. 5.

Brain regional networks that showed significant age-efficiency correlations across more than half of the range from 0.10 to 0.40 of connection densities for (A) dominant and (B) nondominant hand grip when considering 16 brain regions. In the upper and lower panels, red and blue indicate positive and negative correlations respectively between age and efficiency of the corresponding intra- or interregional networks. In the lower panel, boxes are used for intraregional network efficiency and lines for interregional network efficiency. Abbreviations: C, contralateral; Cbl, cerebellar; Frn, frontal; I, ipsilateral; L, left; Lmb, limbic and paralimbic; Occ, occipital; Prt, parietal; R, right; SC, subcortical; SM, sensorimotor; Tmp, temporal.