Determination of effective brain connectivity from functional connectivity using propagator-based interferometry and neural field theory with application to the corticothalamic system.
It is shown how to compute both direct and total effective connection matrices (deCMs and teCMs), which embody the strengths of neural connections between regions, from correlation-based functional CMs using propagator-based interferometry, a method that stems from geophysics and acoustics, coupled with the recent identification of deCMs and teCMs with bare and dressed propagators, respectively. The approach incorporates excitatory and inhibitory connections, multiple structures and populations, and measurement effects. The propagator is found for a generalized scalar wave equation derived from neural field theory, and expressed in terms of neural activity correlations and covariances, and wave damping rates. It is then related to correlation matrices that are commonly used to express functional and effective connectivities in the brain. The results are illustrated in analytically tractable test cases.
School of Physics, University of Sydney, New South Wales 2006, Australia; Center for Integrative Brain Function, University of Sydney, New South Wales 2006, Australia; Brain Dynamics Center, Westmead Millennium Institute, Darcy Rd, Westmead, New South Wales 2145, Australia; Cooperative Research Center for Alertness, Safety, and Productivity, University of Sydney, New South Wales 2006, Australia; and Neurosleep, 431 Glebe Point Rd., Glebe, New South Wales 2037, Australia.
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Robinson
D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D004569:Electroencephalography; D008279:Magnetic Resonance Imaging; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D013788:Thalamus / Q000033:anatomy & histology / Q000502:physiology*