Finger Tapping Test and other performance based tests are widely used in the assessment of the functional state of the central nervous system. The aim of the study was to assess the Tapping Test data by method of nonlinear dimensional reduction (by grouping them to various components). The study was performed in the Laboratory of Human Kinetics at the Lithuanian Academy of Physical Education. The fi nger movements data were registered by using a special computer program, created in the laboratory of Kinesiology, Lithuanian Academy of Physical Education. The subjects of the study were 10 athletes aged 12—25 years. All the subjects did a clasical 60 seconds Finger Tapping Test, and the time intervals of each fi nger movement were recorded in milliseconds. All the subjects took part in two investigations: before and after an exhausting training session. The method of nonlinear dimensional reduction of data was created in Kaunas University of Technology in the Department of Applied Mathematics. The results obtained during the study showed that the correlation index helped to get new information about the peculiarities of the central nervous system of the subjects, actualizing the motor acts, and we could also compare different experemental groups. In conclusion we can to point out that the method of nonlinear dimensional reduction allows us to obtain new information about the peculiarities of functioning of the central nervous system. The most sensitive changes can be obtained in case of grouping three intervals. The data become less informative if we use the grouping of two intervals. Using four or more intervals for grouping makes the information more superfi cial again