Poster C39, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Development of the Frontal Aslant Tract (FAT) Using Restricted Diffusion Imaging (RDI)
Dea Garic1, Iris Broce1, Heidy Zetina1, Anthony Steven Dick1; 1Florida International University
The present study aims to characterize age-related differences in microstructure of the Frontal Aslant Tract (FAT). The FAT is a fiber pathway connecting posterior inferior frontal gyrus to pre-supplementary motor area and based on its connectivity is proposed to support language and executive function (Broce et al., 2015). Recent research using spin density of restricted diffusion modeling has shown that increases in restriction diffusivity (RDI) are associated with increases in cell density (Yeh et al, 2016). Similarly, other research shows that neuronal processes, particularly higher packing density and number of axonal membranes, are the primary contributor to diffusion indices (Winston, 2012). Thus, we focus on RDI to assess age-related differences in the FAT. This is the first study to investigate this in typically developing children. We tracked 129 participants (70 females, age range= 0-18 years, M= 8.67) using high angular resonance diffusion-weighted imaging. Regions of interest were manually drawn based on previous anatomical definitions (Catani et al, 2012). We tested the effects of age on RDI values in both left and right FAT using robust regression. RDI in the whole brain increased significantly with age, β = 0.916, t(115) = 19..806, p < 0.001. Also, after controlling for whole brain RDI and gender, RDI in the left FAT increases with age, β = 0.143, t(115) = 2.884, p = 0.007. Broadly, these results have important implications for developmental models of white matter connectivity and provide a working framework for future investigation of atypical white matter connectivity in the FAT.
Topic Area: EXECUTIVE PROCESSES: Development & aging