A straightforward interpretation would be that it describes electrical potential at the position, r→, as linear summation of current densities at positions, r→′, weighted by the distances from the positions of current density components, r→−r→′. It also means that current density components generate electrical potential recordable at a distance from where those components are located. At large distances, electrical potential becomes small, but does not diminish completely. Thus, on one hand, in locations away from the generator, an electrical potential can exist, though its second derivative is zero. On the other hand, in the absence of a strong local generator, local electrical potentials that do exist arrive by volume conduction from generators at other loci. Analyses based on this equation were found in several recent publications (Avitan et al., 2009; Gold et al., 2006; Ibarz et al., 2010; Logothetis et al., 2007). In this study, we substituted CSD signals for q(r→) to calculate a spatial LFP profile, LFPcal, that a given CSD configuration would generate in response to tones of each frequency. For each recording site, we calculated the similarity,
