New Method for the Study of Spontaneous Brain Activity

摘要

A new method has been developed to characterize the sources of spontaneous brain activity measured magnetically while avoiding any specific model for the neural generators. In an application of the technique, individual spindles of the alpha rhythm monitored by a set of 14 magnetic sensors fixed over the occipital lobe were characterized as vectors in a 14-dimensional signal space. Taking the noise level into account, the number of distinct vectors could be determined, which indicates the number of sources that differ in their geometrical attributes such as position, orientation, and extent. In a pilot study of about 30 spindles for each of two subjects, virtually all sources were distinguishable from the others, implying a large set of underlying generators. Keywords: Magnetoencephalograms.