A test for constant natural frequencies in electrocortical activity under lateral hypothalamic control.

An initial test for a theory of lateral hypothalamic regulation of electrocortical activity is undertaken. The theory supposes lateral hypothalamic input directly or indirectly damps telencephalic resonances involving linear wave phenomena, enabling this pathway to act as parametric control of information processing in cortical neural networks. Relative changes in left and right electrocortical power spectra are used to test for the presence of resonant modes with constant natural frequencies in conditions of asymmetrical damping, following unilateral lesion of the lateral hypothalamus. Natural frequency values for the modes clustered about center frequencies in the EEG band are obtained. This method has the advantage of minimising the effects of time-variation and the recorded signal's distortion from the electrocortical local spatial average, but limits consideration to five dominant modes of resonance. The uncertainty of true model order, and errors in curve-fitting impose limitations on the test.