Sean Tobyne¹, David Osher², Samantha Michalka³, David Somers4
¹Boston University, ²Boston University, ³Boston University, 4Boston University
Recent work in our laboratory (Michalka et al., in review) has identified two sensory-biased attention networks, one visual and one auditory, that include four bilateral regions in human caudolateral prefrontal cortex (clPFC). Two auditory-biased attention regions, caudal inferior frontal sulcus (cIFS) and the transverse gyrus intersecting the precentral sulcus (tgPCS), anatomically alternate with two visual-biased attention regions in superior and inferior precentral sulcus (sPCS, iPCS). These interleaved networks could have important clinical implications; however, the original observations stem from difficult visual/auditory attention tasks with small N. here, we are developing and validating non-task-based fMRI methods for identification of these networks in large numbers of individual subjects. We employed resting-state functional connectivity, which is easily collected from clinical populations. We mined data (N=240) from the Human Connectome Project dataset. We generated probalistic regions of interest from our (N=9) individual subject data. Intrinsic functional connectivity (iFC) analyses revealed highly selective iFC between clPFC visual-biased and parietal visual attention regions and, conversely, stronger iFC between the clPFC auditory-biased and superior temporal lobe auditory attention regions. Antiphase sinusoids fitted to visual and auditory iFC values confirmed a consistently interleaved spatial layout at the group level. Finally, variability in peak-to-peak distance was characterized by fitting mixed Gaussians to the data to quantify the shifting spatial layout of these regions across subjects. Our results provide large-scale validation for the interleaved auditory-visual organization of lateral frontal cortex and demonstrate our ability to localize these regions in individuals using iFC methods suitable for use with clinical populations.
Keywords: Attention, Functional Connectivity, HCP