Analytical methods and devices for analyzing biological signals, for example, electrical signals from the brain to determine whether an abnormal condition caused by a medical condition exists. In one embodiment, the medical disorder may be epilepsy. The analytical methods include wavelet analysis and neighbor cross-correlation count, which is a frequency specific measure of the degree of correlation of a single channel of data with respect to its neighbors. The devices according to the invention are programmed to include the analytical methods and to administer treatment regimens such as electrical stimulation, heating, cooling and medication as needed.