Otten, K. | bioRxiv Science

bioRxiv2024

Functional and structural maturation of auditory cortex from 2 months to 2 years old

In school-age children, the myelination of the auditory radiation thalamocortical pathway is associated with the latency of auditory evoked responses, with the myelination of thalamocortical axons facilitating the rapid propagation of acoustic information. Little is known regarding this auditory system function-structure association in infants and toddlers. The present study tested the hypothesis that maturation of auditory radiation white-matter microstructure (e.g., fractional anisotropy (FA); measured using diffusion-weighted MRI) is associated with the latency of the infant auditory response (P2m measured using magnetoencephalography, MEG) in a cross-sectional (2 to 24 months) as well as longitudinal cohort (2 to 29 months) of typically developing infants and toddlers. In the cross-sectional sample, non-linear maturation of P2m latency and auditory radiation diffusion measures were observed. After removing the variance associated with age in both P2m latency and auditory radiation diffusion measures, auditory radiation still accounted for significant variance in P2m latency. In the longitudinal sample, latency and FA associations could be observed at the level of a single child. Findings provide strong support for a contribution of auditory radiation white matter to rapid cortical auditory encoding processes in infants.

neuroscience↗

bioRxiv2019

Partners in health? Investigating social genetic effects for married and cohabiting couples.

Social contagion research suggests that health behaviors (BMI, smoking, drinking, etc.) spread through social networks, including dyadic ties such as between married/cohabiting partners. However, separating contagion from assortative mating ( like seeks like) and shared environmental factors remains notoriously difficult in observational studies. It is not possible to obtain exogenous variation in long-term partnerships ( random mating), but genetic approaches can offer a novel way to examine partner similarity and the role of social contagion. This paper explores possible social genetic effects among partners, i.e., effects of the partners genes on ones own behavior. We use the longitudinal Health and Retirement Study with data on health behavior and genomic data for both ego and his/her partner to examine social genetic effects for BMI, drinking, and smoking behavior. For each outcome, we find support for social genetic effects. Americans of European descent were more overweight if they had partners with higher polygenic scores for BMI net of their own polygenic score. Similar findings were found for the number of drinks per week and cigarettes per day. Longitudinal analyses that conditioned on past health behavior of both spouses confirmed these findings. We further explored whether susceptibility to the partners influence differed between men and women, but did not find consistent differences across outcomes. Findings are further discussed in the light of ramifications of social genetic effects for the social and biological sciences.

genomics↗