1. A method for detecting epileptiform activity, the method comprising: obtaining brain wave signal data from a subject; decomposing the brain wave signal data into at least one predetermined subband, to obtain subband-specific output data representing a time series of a quantitative characteristic of the brain wave signal data, wherein each subband is indicative of a specific type of epileptiform activity; determining at least one measure for at least one of the at least one predetermined subband, the at least one measure belonging to a measure set comprising a first measure indicative of the entropy of the subband-specific output data and a second measure indicative of a normalized form of k:th order central moment of the subband-specific output data, where k is an integer higher than three; and indicating, based on the at least one measure of the respective subband, whether a specific type of epileptiform activity is present in the brain wave signal data.