You are viewing the SNL 2017 Archive Website. For the latest information, see the Current Website.

 
Poster E71, Friday, November 10, 10:00 – 11:15 am, Harborview and Loch Raven Ballrooms

White matter matters: aging of the arcuate fasciculus and middle longitudinal fasciculus and their impact on hearing and speech perception

Pascale Tremblay1, Maxime Perron1, Isabelle Deschamps1, Daniel Kennedy-Higgins2, Anthony S. Dick3, Maxime Descoteaux4;1Université Laval, 2University College London, 3Florida International University, 4Université de Sherbrooke

INTRODUCTION. The aging human brain experiences significant white matter (WM) changes. Such changes have been linked with cognitive decline. In this study, we used High Angular Resolution Diffusion Images (HARDI) with advanced tractography methods to investigate aging of two WM tracts that are thought to be involved in speech and language functions, the arcuate fasciculus (AF), with its three components (anterior, posterior and direct) and the middle longitudinal fasciculus (MdLF), with its two different components, one connecting the temporal pole (TP) to the inferior parietal lobule (IPL) and one connecting TP to the superior parietal lobule (SPL) (Makris et al., 2013). METHODS. 14 young and 15 older cognitively healthy adults were recruited. They underwent a hearing evaluation and completed an auditory syllable discrimination task. Using a Philips 3.0 Tesla Achieva TX, a MPRAGE (1 mm3 and a HARDI sequence were acquired (TR = 8,5 ms ; TE = 76.7 ms; b=1500 s/m2, 60 directions, 128 volume, no gap, 1.8 mm). Image preprocessing was completed using Freesurfer and FSL. Tractography analyses were computed using DIPY (Descoteaux et al., 2008; Garyfallidis et al., 2014). Here we report the results for the fractional anisotropy (FA) and radial diffusivity (RD). PRELIMINARY FINDINGS. We could track all components of the AF and MdLF in all participants. AF. For FA, a mixed-model ANOVA showed a main effect of Group (F(1,26) = 18.17, ≤ .001, η2 = .41) and an interaction between Tracts (direct, anterior, posterior) and Group (young, older) (F(2,52) = 6.79, p = .002, η2 = .21), which revealed a stronger age difference in the posterior tract. A 3-way interaction was found between Group, Tracts and Hemisphere (F(2,52) = 4.69, p = .013, η2 = .15). In the anterior and posterior tracts, age-related decline was bilateral while it was unilateral (left) in the direct tract. For RD, the ANOVA showed a main effect of Group (F(1,26) = 15.88, ≤ .001, η2 = .38) and an interaction between Tracts and Group (F(2,52) = 3.7, p = .032, η2 = .12), which revealed a stronger age difference in the posterior component. MdLF. For FA, the ANOVA showed a main effect of Group (F(1,27) = 29.19, p ≤ .001, η2 = .52), as well as an interaction between Tracts (IPL, SPL) and Group, which revealed a stronger age difference in IPL (F(1,27) = 21.42, p ≤ .001, η2 = .442). No hemisphere effect was found. For RD, there was a main effect of Group (F(1,27) = 16.95, p ≤ .001, η2 = .39), and an interaction between Tracts and Group, which revealed a stronger age difference in SPL (F(1,27) = 5.03, p = .033, η2 = .157). No hemisphere effect was found. CONCLUSIONS. Analyses are currently underway to examine whether these age differences in WM can explain age differences in hearing and speech perception. We expect that these differences in WM integrity result in an impairment in neural signal conduction in key speech and language networks of the brain leading to speech deficits.

Topic Area: Perception: Speech Perception and Audiovisual Integration

Back to Poster Schedule