title: Response inhibition deficits in children with Fetal Alcohol Spectrum Disorder: relationship between diffusion tensor imaging of the corpus callosum and eye movement control.
abstract: Response inhibition is the ability to suppress irrelevant impulses to enable goal-directed behavior. The underlying neural mechanisms of inhibition deficits are not clearly understood, but may be related to white matter connectivity, which can be assessed using diffusion tensor imaging (DTI). The goal of this study was to investigate the relationship between response inhibition during the performance of saccadic eye movement tasks and DTI measures of the corpus callosum in children with or without Fetal Alcohol Spectrum Disorder (FASD). Participants included 43 children with an FASD diagnosis (12.3 ± 3.1 years old) and 35 typically developing children (12.5 ± 3.0 years old) both aged 7-18, assessed at three sites across Canada. Response inhibition was measured by direction errors in an antisaccade task and timing errors in a delayed memory-guided saccade task. Manual deterministic tractography was used to delineate six regions of the corpus callosum and calculate fractional anisotropy (FA), mean diffusivity (MD), parallel diffusivity, and perpendicular diffusivity. Group differences in saccade measures were assessed using t-tests, followed by partial correlations between eye movement inhibition scores and corpus callosum FA and MD, controlling for age. Children with FASD made more saccade direction errors and more timing errors, which indicates a deficit in response inhibition. The only group difference in DTI metrics was significantly higher MD of the splenium in FASD compared to controls. Notably, direction errors in the antisaccade task were correlated negatively to FA and positively to MD of the splenium in the control, but not the FASD group, which suggests that alterations in connectivity between the two hemispheres of the brain may contribute to inhibition deficits in children with FASD.
authors: Centre for Neuroscience Studies, Queen's University, Kingston, ON K7L 3N6, Canada.
authors: Angelina
authors: A
authors: Paolozza
authors: Centre for Neuroscience, University of Alberta, Edmonton, AB T6G-2E1, Canada.
authors: Sarah
authors: S
authors: Treit
authors: Centre for Neuroscience, University of Alberta, Edmonton, AB T6G-2E1, Canada ; Department of Biomedical Engineering, University of Alberta, Edmonton, AB T5G 0B7, Canada.
authors: Christian
authors: C
authors: Beaulieu
authors: Centre for Neuroscience Studies, Queen's University, Kingston, ON K7L 3N6, Canada ; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada.
authors: James N
authors: JN
authors: Reynolds
mesh_terms: D016880:Anisotropy; D002648:Child; D003337:Corpus Callosum / Q000503:physiopathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D063647:Fetal Alcohol Spectrum Disorders / Q000503:physiopathology* / Q000523:psychology; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008568:Memory / Q000502:physiology*; D009483:Neuropsychological Tests; D012438:Saccades / Q000502:physiology*
keywords: DTI, diffusion tensor imaging; Diffusion tensor imaging; Eye movement control; FA, fractional anisotropy; FASD, Fetal Alcohol Spectrum Disorder; FP, fixation point; Fetal Alcohol Spectrum Disorder; ICC, Intraclass correlation coefficient; MD, mean diffusivity; ROI, region of interest; Response inhibition; SRT, saccadic reaction time