The perceptive faculties of a subject are determined by way of a brain-computer interface 20. At least two mutually distinguishable types of stimuli SA, SB which are applicable to a subject are prescribed. A multiplicity of temporally successive stimuli are applied to the subject and combined to form blocks. Calibration data are created from the EEG data ascertained thus by virtue of a number of ascertained EEG data and stimuli associated with these EEG data are combined to form calibration blocks. A classification function is ascertained by a classification analysis on the basis of ascertained calibration blocks. The classification function specifies a position of the stimulus of the first type in the respective calibration block. Finally, the EEG data of a number of test blocks selected from the blocks are subjected to the classification function.