text: Although studied to a lesser degree, ties between maternal 
  behavior and white matter microstructure (particularly connectiv- 
  ity between temporal and occipital lobes) have been noted31. Here we 
  reveal pronounced GMV changes in regions within sensory, attention 
  and default mode networks over the gestational window. In paral- 
  lel, we observed increased anisotropy in white matter tracts that 
  facilitate communication between emotional and visual processing 
  hubs37–39, including the inferior longitudinal fasciculus and inferior 
  fronto-occipital fasciculus. Pinpointing the synchrony of gray and 
  white matter changes that unfold in the maternal brain could be 
  key to understanding the behavioral adaptions that emerge during 
  and after pregnancy, such as honing the brain’s visual and auditory 
  responses to infant cues and eliciting maternal behavior. Research 
  into other major transition periods supports this idea. For instance, 
  adolescence is a dynamic period characterized by region-specific, 
  nonlinear decreases in GMV and increases in WMV, maturational 
  brain changes that are tied to gains in executive function and social 
  cognition40. For both adolescence41 and matrescence, the consider- 
  able rise in steroid hormone production appears to remodel the brain 
  (see ref. 25 for comparative analysis), promoting a suite of behaviors 
  adaptive to that life stage. How specific neural changes give rise to 
  specific behavioral adaptations has yet to be fully explored with 
  respect to human pregnancy. 