When does the youthfulness of the female brain emerge?

Abstract

Goyal et al. (1) report in PNAS that the female adult brain has a persistently lower metabolic brain age compared with the male brain at the same chronological age. In interpreting this remarkable finding, the authors propose that sex-related differences in brain development may, in part, play a role in “setting” the female brain at a younger initial brain age at puberty, allowing them to maintain a younger brain throughout adulthood. We argue that this may not be the case and provide evidence to show that, in fact, the opposite may be true during childhood and adolescence. First, according to figure 2A of ref. 1, surprisingly, the predicted age between 35 and 50 y was underestimated for both males and females. It is unclear if the bias in this age range could have affected the overall findings or played a role in only the result from training on males and testing on females surviving a two-sided t test. Moreover, it is unclear … [↵][1]1To whom correspondence should be addressed. Email: nmaleki{at}mgh.harvard.edu. [1]: #xref-corresp-1-1