A three-dimensional map of the probability of brain or heart functional states is obtained based on electric or magnetic signals, or a combination of both measured in the surface of body. From signals, the statistical descriptive parameters are obtained and a map of its distribution is calculated. The map is the inverse solution of the problem based upon: a) the restriction of the solution to structures with high probability of generating electric activity using for this restriction an Anatomical Atlas and b) imposing that the solution belong to a pre-specified functional space. The probability is determined that this map belongs to a test group. The spatial and temporal correlations of the map are modeled as well as their dependence on experimental covariables. The resulting probabilities are coded in a pseudocolor scale and they are superimposed on a Anatomical Atlas for their interactive three-dimensional visualization.