The present invention relates to a medical data processing method for identifying an entity of the nervous system, in particular the brain, of a patient, wherein the method is designed to be executed by a computer and comprises the following steps: a) acquiring target connectivity data comprising target connectivity information about the probability of a target entity being connected to other entities of the nervous system; b) acquiring candidate connectivity data comprising candidate connectivity information about the probability of at least one candidate entity being connected to other entities of the nervous system; and c) determining similarity data for each of the at least one candidate entities on the basis of the candidate connectivity data and the target connectivity data, wherein the similarity data comprise similarity information about the similarity between the candidate entity and the target entity.