Poster A32, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
Functional neural correlates of selective attention deficits in Cerebral Small Vessel Disease: a multi-modal approach to exploring variability in vascular cognitive impairment
Ayan Dey1,2,3, Vessela Stamenova2,3, Alissa Papadopoulos2, Laura Oliva2, Laryssa Levesque2, Gary Turner1,4, Sandra E. Black1,2,3,5, Brian Levine1,2,3; 1University of Toronto, Canada, 2Rotman Research Institute at Baycrest, Toronto, Canada, 3Canadian Partnership for Stroke Recovery, 4York University, Toronto, Canada, 5Sunnybrook Health Sciences Center, Toronto, Canada
Background: Cerebral small vessel disease (CSVD) on imaging is characterized by the presence of white matter hyperintensities and lacunes and manifests behaviourally as deficits in executive function and speed of processing. Structural neuroimaging measures however only partially account for the heterogeneity of behavioural outcomes observed in CSVD, with many patients showing no impairment despite significant lesion burden. Objective: The purpose of this study is to investigate whether better cognitive performance within the CSVD population is associated with greater frontal activation, preserved attention network functional connectivity and more robust selective feature processing. Methods: Neuropsychological measures were decomposed into factors scores for executive dysfunction and processing speed. Volumetric measures of lesion burden were obtained using Fuzzy Lesion Extractor (FLEX). Following a 6 minute resting scan, participants were asked to complete a visual N-back task involving faces and scenes while electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) data was recorded simultaneously. Amplitude of the selection negativity, a marker of selective feature processing, was extracted from EEG data, whereas for the fMRI data, brain-behaviour relationships were analyzed using Partial Least Square (PLS) analysis. Results: Behavioural data confirm the presence of a subgroup of high performing adults with clinically significant levels of lesion burden. EEG data provide evidence of attenuated selection negativity among adults with CSVD suggesting that attention deficits may be rooted in failure to promote perceptual enhancement. Analysis of the fMRI data also suggest that CSVD is associated with reduced connectivity between anterior and posterior hubs of the default mode network (DMN).
Topic Area: EXECUTIVE PROCESSES: Development & aging