Studies of conductance fluctuations can reveal important information concerning defect kinetics and transport mechanisms not revealed in conventional electronic techniques. Studies of conductance fluctuations (1/f noise) in hydrogenated amorphous silicon (a-Si:H) by my laboratory have been interpreted as reflecting the dynamics of inhomogeneous current filaments, believed to arise from medium and long-ranged structural disorder. The non-Gaussian statistics of the 1/f noise is characterized by measurements of the second spectra, obtained from Fourier transforms of the time-dependent fluctuations of the 1/f noise power. The second spectra in a-Si:H films itself displays a 1/f frequency dependence, reflecting electronic correlations between differing current microchannels. That is, in a-Si:H, the 1/f noise has 1/f noise! These studies have been extended to analyze local field potentials recorded from rats perfroming neurological studies. Brains consist of non-linear neurons linked together in complex networks, suggesting that neural systems will show cooperative dynamics. We have discovered that the correlation coefficients of the power spectra of the voltage fluctuations recoded while the rat is performing a variety of tasks are highly sensitive to transient coherent oscillations that can typically only be discerned by filtering techniques. These results indicate that this novel technique may be useful in measuring functional interactions in neural systems.