Phase measures in the study of brain responses

EEG stimulus-related responses have been for years one of the main tools in the study of the brain. Traditionally, these responses have been considered as the result of the generation of low-amplitude evoked potentials. When averaged, these low-amplitude potentials come up from the background EEG, and can be clearly observed. Recent studies, however, evidence that these evoked small-amplitude waves might not to be the only generator mechanism of the EEG responses. Some components seem to be generated by stimulus-induced changes in ongoing brain dynamics. Therefore, new techniques are needed to make feasible the study of the brain responses from this new point of view. Here we use and adapt some phase-based measures that work more accurately when some traditional and not so traditional techniques seem to fail.