Effect of music on cortical GM NODDI metrics
NDI
CORTEX
A complementary cortical GM NODDI analysis was performed, in order to better understand the observed longitudinal FBA microstructural changes related to the music intervention on the cortical GM. For that, masks containing the cortical regions showing a significantly superior longitudinal increase of FC in PTM in comparison to PTC infants were warped from the population template to the subject space, at each time point. These cortical masks were then used to evaluate the NODDI parameters longitudinal evolution differences between both groups. The masks used comprised (as described in For both groups, in all cortical regions evaluated, there was a significant ODI increase over time, from the 33rd week GA to term-equivalent age (p < 0.0001).When comparing the NODDI metrics longitudinal changes between groups, in comparison to PTC, PTM had a significantly superior ODI increase in the left temporal pole (F(1,33)= 5.201, p = 0.029) and left orbito-frontal cortex (F(1,33)= 4.973, p = 0.033). In the other cortical regions, namely the right middle temporal gyrus, left insula and right precuneus/posterior cingulate gyrus, there was a tendency for a superior ODI longitudinal increase in the PTM vs PTC group, but without a statistically significant difference (ODI longitudinal changes per group, from the 33rd week GA to term-equivalent age, in the cortical GM regions that had a significant longitudinal FC increase in PTM in comparison to PTCThe additional inclusion of the socio-economic parental status score (SES) as a covariate in the model led to similar results: in comparison to PTC, PTM had a significantly superior ODI increase in left temporal pole (p = 0.021) and left orbitofrontal cortex (p = 0.026); the other three cortical regions remained non-significant (right middle temporal cortex [p = 0.510], left insula [p = 0.167] and right precuneus/posterior cingulate gyrus [p = 0.850]).No significant differences between groups were found for NDI in all the evaluated cortical regions (p > 0.05).