23 Results of the intellectual test performance were processed manually. The percentage of completed intellectual tasks is given in the manuscript. NSC was processed by computer program recording 5-minute cardiointervals. Cardiointervals were processed on-line and presented in a digital form. Mean values of RR- intervals (inter-beat intervals), mean square deviation of cardiointervals (MSD RR – estimation of rhythm variability), LF/HF ratio (measure of the activity of the sympathoadrenal and parasympathetic centers of the autonomic nervous system), So (spectral power at the lowest frequency of the power spectrum obtained by fast Fourier transform) were recorded. So is associated with an activation of neuronal networks of cortical fields. Fractal ß index is an indicator of the degree of system organization of the cortical control of the heart rhythm. The lower the value of the fractal index is, the higher chaotization of homeostasis in higher levels of the heart rhythm control system is. The optimization of the cardiac rhythm control system is observed in the range of the fractal index from -0.8 to -1.0. Results Before analyzing qualitative features and quantitative differences in the intellectual test performance and NSC parameters recorded during verbal tasks and background cardiointervalometry, it was necessary to validate empirical data for their compliance with a normal distribution law. According to the verification by Kolmogorov-Smirnov’s test all empirical findings corresponded to the normal distribution law. Maximum deviations from this law were noted in the corticolization index (So) reflecting the contribution of the cortical activity to the regulation of the cardiac one. Table 1 shows mean values with standard deviation variates of the Raven’s test performance and verbal activity quotients in three situations: 1) neutral conditions without reward (background AE), 2) the one with a positive reward (AE+) and 3) that with a negative reward (AE-). Similar parameters of the intellectual activity were observed in boys and girls. Standard Student t-test for independent samples didn’t show significant differences between groups of boys and girls (Student t-test values are in the range from .546 to .889).