21348
Association Between Microstructural Properties of the Uncinate Fasiculus and Emotion Recognition in Women with and without Autism Spectrum Conditions
Objectives: This study aims to investigate interactions between neuropsychological tasks measuring emotion recognition and mentalizing and microstructural properties of the uncinate fasciculus (UF; which connects the frontal and temporal lobes) in women with and without ASC.
Methods: 42 age- and IQ-matched women with (n=21) and without ASC were scanned ( 3T GE) using a cardiac-gated 32-direction diffusion-weighted sequence. ExploreDTI was used for preprocessing (Leemans, et al., 2009) and UF deterministic tractography was performed according to guidelines given by Catani & Thiebaut de Schotten (2008) using TrackVis software (http://trackvis.org). Participants completed the “Reading the Mind in the Eyes” (RMET) and the Karolinska Directed Emotional Faces (KDEF) tasks. Number of correct responses was used to test for group differences in performance on the RMET, and log-transformed accuracy-adjusted reaction times (aaRT; mean reaction time divided by accuracy) were used for each individual emotion on the KDEF. A multivariate repeated-measures analysis of covariance (MANCOVA) was performed on fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD) and tract volume respectively, with ‘hemisphere’ as within-subjects factor, ‘diagnosis’ as between-subject factor, and ‘IQ’ as a covariate. Any significant interaction effects were followed up by post-hoc ANCOVAs.
Results: On average, typically developing (TD) females performed better on the RMET (TD, 28.5; ASC, 23.0; F(1,38) = 10.1, p = 0.003) and identified “happy” KDEF expressions faster (TD, 1561ms; ASC, 1925ms; F(1,38) = 9.82, p = 0.003). No group differences were found for other emotional KDEF expressions. There were no group differences in FA, MD, number of streamlines or volume of the UF. Significant hemispheric asymmetries were found across groups for FA and MD, with higher FA (F(1,40) = 31.6, p < 0.001) and lower MD (F(1,40) = 14.9, p < 0.001) in the right UF. In women with ASC, higher FA in the right UF was related to better identification of the “happy” facial expression (TD: r = -0.36, p = 0.12, ASC: r = -0.44, p = 0.05) and higher MD of the right UF was associated with better performance on the RMET (TD: r = -.03, p = 0.89, ASC: r = 0.45, p = 0.04). Fisher’s Z-test was used to compare the correlation coefficients and showed that there were no significant group differences.
Conclusions: This is the first study that investigates if and how microstructural properties of WM in TD and ASC females relate to socio-emotional task performance. Two significant correlations were found between microstructural properties of the right UF and performance on mentalizing tasks. However, post-hoc Fisher’s Z-test determined that the effect sizes were not significantly different between groups. Future research should investigate if socio-emotional task performance in autism can be predicted by any other WM tracts.
See more of: Brain Structure (MRI, neuropathology)