Measures of fractal connectivity and physical embedding in computational and nervous systems.

connection density; , Euclidean (embedding) dimension; , observed topological Rent's exponent; , fractal dimension of network topology estimated from the topological Rent's exponent, ; , observed physical Rent exponent; , mean connection distance between nodes (Eq 6); , measure of cost-efficient embedding (Eq 4). Errors reported are 95% confidence intervals for fits of , ; and standard deviation over individual subject's values for the DSI estimations of and . For the DSI estimations of , , and , combined errors () are reported which include the errors of fit () and individual variation () as given by (see supplementary Text S1 for results from individual DSI scans). Values for the randomly rewired networks are averages over 10 random network instantiations.