Abstract #0636

Resting-state Correlations Between Depths Within Columns of Voxels Radial to the Cortical Surface

Jonathan Rizzo Polimeni¹, Kyoko Fujimoto¹, Boris Keil¹, Douglas N. Greve¹, Bruce Fischl^1,2, Lawrence L. Wald^1,3

¹A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA; ²Computer Science & AI Lab (CSAIL), Massachusetts Institute of Technology, Cambridge, MA, USA; ³Harvard-MIT Division of Health Sciences & Technology, Massachusetts Institute of Technology, Cambridge, MA, USA

Here we provide characterization of the radial independence of the fluctuations at each depth below a given cortical location. This radial correlation length of resting state fluctuations was measured using gradient echo and spin echo EPI. The radial correlation length is strongly affected by the removal of confounding physiological signals in a counter-intuitive way--namely the global signals regressed out do not seem to produce an artifactual high-correlation between layers, but rather mask the presence of correlations between different depths. Similarly, the spin echo acquisition, which is also expected to remove relatively global fluctuations also uncovers additional underlying radial correlations.