Aliev R.R. Examples of wavelet transformations, Granger causality test, statistical techniques are shown to be useful for the analysis of quasi periodic field and spike activity of the brain. In particular, phase relationships and causality of theta-rhythms in hippocampus and MSO are studied during epilepsy and in the norm. Wavelet transformations are demonstrated to be useful to study evoked potentials. Energy transformations between delta, theta, and alpha bands are shown. A comparative usage of wavelet and Fourier transformations is shown while studying a protector role of fullerenes on the amyloid model of the Alzheimer's disease. An alternative usage of wavelets for data filtering is demonstrated while studying spike activity of the neurons affected by neuropeptides in migraine pathology. Further analysis of data is carried out with the aid of statistical methods.