PUBERTY-RELATED MICROSTRUCTURAL AND GABAERGIC MATURATION SUPPORTING SPEECH-IN-NOISE PROCESSING

From classrooms to social gatherings, children’s lives are noisy, yet the ability to perceive speech in noise (SiN) matures well into adolescence. Adolescence represents an extended period of neuroplasticity that promotes experience-driven brain adaptations underlying cognitive and behavioural capacities required in dynamic social environments. It begins with puberty onset, which is associated with changes in sex-steroid hormones that contribute to the maturation of brain regions involved in SiN. Within the SensationaHL pubertal cohort, we investigate the neuroplastic and microstructural brain mechanisms linked to pubertal progression in brain regions serving complex cognitive and auditory skills. We hypothesize that neurite density trajectories correlate with pubertal progression. We also predict puberty-associated increases in gamma-aminobutyric acid (GABA) concentrations, a key modulator of neuroplasticity, in SiN regions of interest: the left pars triangularis and left Heschl’s gyrus. We are currently collecting neuroimaging data from wave 1 of a longitudinal cohort of 150 participants (current n = 101), including single-voxel spectroscopy, and diffusion imaging to evaluate GABA concentration as well as microstructural changes. Results from cross-sectional MRI data will be presented, in relationship with SiN performance. Preliminary findings (n ~ 50) suggest an increase in neurite density throughout adolescence, but stable orientation dispersion as well as stable GABA concentration values within the targeted regions across age and pubertal status. Findings will be discussed with respect to the neurobiological triggers of heightened auditory plasticity during adolescence and the relationship between puberty, cognitive and auditory development in noisy environments.