Poster E95, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
Whole brain mapping of functional connectivity pattern dissimilarity reveals focal changes in task-dependent coupling across reasoning, memory, and perception
Xiaoye Zuo1, Andrew J. Westphal1, Jesse Rissman1; 1University of California, Los Angeles
Researchers interested in characterizing task-dependent changes in functional connectivity have traditionally relied on seed- or node-based approaches. However, advances in computing have made it possible to measure the connectivity between every voxel and every other voxel in the brain, an approach dubbed ‘full correlation matrix analysis’ (Turk-Browne, 2013). We applied such an approach to fMRI data from 20 participants to identify regions that showed the greatest changes in their functional connectivity properties across three distinct cognitive tasks. Importantly, these tasks shared identical stimulus characteristics and response demands, but differed in their engagement of analogical reasoning, episodic memory retrieval, and visuospatial perceptual processes. For each voxel in the brain, we generated a whole brain functional connectivity map for each task, and computed the dissimilarity of these maps as an index of task-dependence. Consistent with our prior work demonstrating commonalities in cortical engagement during reasoning and memory (Westphal et al., 2016), the connectivity properties of memory and reasoning were generally more similar to each other than to the perception task. Areas showing maximally divergent connectivity during perception included left posterior intraparietal sulcus, inferior frontal gyrus, and lateral occipital cortex. Our analyses also identified regions with marked alterations in their functional connectivity patterns across all three tasks, with peak effects found in default mode regions such as left posterior cingulate cortex and dorsal superior frontal gyrus, as well as several task-positive frontoparietal regions. Such data-driven findings can be followed up with seed-based analyses to more fully isolate the task-dependent changes in inter-regional coupling.
Topic Area: METHODS: Neuroimaging