Procedure for the quantification of the cognitive capacity of a person (1) who does not have other possibilities for communication, such as language or gestures, as well as for subsequent communication with this person (1), a) predetermining a quantity of at least two possible differently perceptible types of stimuli (S) applicable to the volunteer (1), applying vibration loads to the person (1) in different parts of the body and / or with different intensity and / or duration by means of units vibration, and b) asking the volunteer (1) intellectual activities that must be carried out in the presence of a stimulus (S), depending on the type of this stimulus (S), c) performing a variety of test steps, where for each one of the test steps - a type of stimulus (S) is selected from the number of possible types of stimuli (S), especially according to random criteria, - a stimulus (S) is applied to the person (1) of the type of stimuli selected in each case, - in a time interval before, during or after the application of the respective stimulus (S), EEG data of the person are determined and recorded, the time interval preferably having a duration of 1 to 10 seconds, and - the EEG data determined in each case are averaged, and the evoked potentials, determined in such a way, are assigned to the respective stimulus (S), d) determining by means of classification variance analysis (105) a measure (M ) on whether the EEG data assigned to a certain stimulus (S) can be differentiated from the EEG data assigned to a stimulus (S) of a different type, and e) using the measure (M) of the differentiation of the data of EEG of different stimuli (S) as a measure of cognitive capacity, which indicates to what extent it is still possible to communicate with its environment, - asking, once the measurement (M) of the person's cognitive capacity (1) has been made for communication, especially for affirmation and denial of questions, carrying out the intellectual activities previously used,
