hemodynamic traveling waves in human visual cortex人类视觉皮质血流动力学波旅行.pdfVIP

Hemodynamic Traveling Waves in Human Visual Cortex 1 2,3 1,4 1,4 5,6,7,8 Kevin M. Aquino *, Mark M. Schira , P. A. Robinson , Peter M. Drysdale , Michael Breakspear 1 School of Physics, University of Sydney, New South Wales, Australia, 2 Neuroscience Research Australia, Randwick, New South Wales, Australia, 3 School of Psychology, University of New South Wales, Kensington, New South Wales, Australia, 4 Brain Dynamics Center, Sydney Medical School – Western, University of Sydney, New South Wales, Australia, 5 Queensland Institute of Medical Research, Herston, Queensland, Australia, 6 School of Psychiatry, University of New South Wales, Sydney, New South Wales, Australia, 7 The Black Dog Institute, Sydney, New South Wales, Australia, 8 The Royal Brisbane and Women’s Hospital, Brisbane, Queensland, Australia Abstract Functional MRI (fMRI) experiments rely on precise characterization of the blood oxygen level dependent (BOLD) signal. As the spatial resolution of fMRI reaches the sub-millimeter range, the need for quantitative modelling of spatiotemporal properties of this hemodynamic signal has become pressing. Here, we find that a detailed physiologically-based model of spatiotemporal BOLD responses predicts traveling waves with velocities and spatial ranges in empirically observable ranges. Two measurable parameters, related to physiology, characterize these waves: wave velocity and damping rate. To test these predictions, high-resolution fMRI data are acquired from subjects viewing discrete visual stimuli. Predictions and experiment show strong agreement, in particular confirming BOLD waves propagating for at least 5–10 mm across the cortical surface at speeds of 2–12 mm s-1. These observati