Global Neuromagnetic Cortical Fields Have Non-Zero Velocity
Fig 2
Typical wavelength spectrum and distribution of peak wavelengths over all samples.
The top panel shows the spatial frequency spectrum for a single sample of one subject’s MEG. The peak in the wavelength spectrum in this case was at 27cm. The bottom panel shows the distribution of peak spatial frequencies over the entire population of samples. The bulk of waves have wavelength between 25 and 35cm, with delta band (1 to 4Hz) having slightly higher wavelengths compared to beta band (16 to 28 Hz).