Spatiotemporal Dynamics of Low Frequency Fluctuations in BOLD fMRI of Rats and Humans

Introduction: Functional connectivity and spontaneous low frequency fluctuations (LFFs) in the BOLD signal [1] have gained considerable interest among the fMRI and neuroscience communities in the past few years. Current techniques for analyzing spontaneous LFFs (correlation maps, ICA, clustering) assume steady state and do not provide insight into spatiotemporal dynamics of the LFFs [1, 2, 3]. A recent investigation into spatiotemporal dynamics of LFFs showed presence of propagating waves in the rat cortex using visual inspection of the filtered data [4]. This work investigates presence of spatiotemporal patterns in multislice data obtained from humans and rats using a novel automatic pattern finding approach.