In other words, CSD estimates more accurately index the source of neuronal activity from the underlying generators (Nunez et al. 1997; Tenke and Kayser 2012). Given minimal effects of reference and volume conduction on CSD estimates, coherence measures based on these estimates would more truthfully capture the relationship between two electrodes. CSD estimates were computed using the 4th order spherical spline interpolation, and a maximal degree of Legendre polynomials of 10 (Perrin et al., 1989).
