Assessing Perinatal Maturation of Human Primary and Nonprimary Auditory Cortex
* Presenting author
In general, primary sensory cortex matures in advance of nonprimary sensory cortex, but the timing differences between primary (pAC) and nonprimary auditory cortex (nAC) maturation in humans is unclear. Here we used diffusion MRI to characterize the maturational timeline of auditory cortex microstructure for preterm infants.We analyzed longitudinal data from infants born preterm who each underwent diffusion MRI up to four times between 26 and 40 weeks postmenstrual age. We examined the variation in diffusion MRI parameters along the length of Heschl’s gyrus. We tested for associations between diffusion metrics in infancy and language developmental outcomes at age 2 years.We were able to distinguish between pAC and nAC as early as 28 weeks postmenstrual age, a time at which the sulcal boundaries of Heschl’s gyrus are just beginning to appear. Our analysis revealed differing rates of maturation along the axis of Heschl’s gyrus as cortex transitions from pAC to nAC. While pAC was further advanced along the developmental timeline at each timepoint, nAC showed much larger changes from 26 to 40 weeks postmenstrual age than did pAC. Disturbed maturation of nAC (but not pAC) was associated with poorer language performance at age two years.