L.Sh. Bedanokova, Ph.D.
A.V. Shakhanova, professor, Dr.Biol.
A.G. Zabolotniy, associate professor, Ph.D.
Sh.D. Bedanokov 
Adyghe State University, Maikop

Keywords: P300 method, cognitive induced potentials, basketball players, judokas.

Introduction. Systematic sports loads have a modeling influence on the formation of the skills of motor actions and tactical thinking [1]. Judo techniques are situational movements that are characterized by high power of performance and changes in the structure of motor actions which leads to high demands on the central nervous system, sensory systems and the motor apparatus [5]. 

In our earlier studies we have shown the influence of training in basketball and judo on the development of students’ speed and functioning efficiency of various links of sensory specific systems involved in the processes of identification (N200), recognition (Р3а), decision making (Р3b), memorization and formation of a «dynamic template» (N3), and the volume and efficiency of using operative memory (PQ interval N200-P300) [1]. The use of three different types of stimulation significantly enhances possibilities to evaluate the impact of sports loads of different purposes on the development of functional capabilities of visual and auditory sensory systems.

The purpose of the study was to consider the scope and nature of changes in the correlations between different indicators of components of cognitive induced potentials identified in response to stimuli in different modalities under the influence of systematic sports loads.

Materials and methods. Cognitive induced potentials were registered with the “Neuro-MVP” (Neurosoft, Ivanovo town) computer complex using the Р300 method in the random sequence of events («odd-ball» paradigm). The essence of the method is to highlight responses under the conditions of identification of a rare meaningful stimulus by a testee, the former being provided in a pseudo-random sequence with a probability of occurrence of 30%. 

The method was performed using stimuli of different modality and complexity (checkerboard pattern reversal, tone click, LED flash). The study was attended on a voluntary basis by 15 students who played basketball in a sports section at the premises of the Department of Physical Education of Adyghe State University; 15 judokas training at the premises of Institute of Physical Culture and Judo at Adyghe State University. The sports experience of the basketball players and judokas averaged at the level of 3.8±0.5 and 8.9±0.5 years. Ten student-basketball players had sports qualification of the I category, and five - of the II category; they trained five times a week all the year round for 1.5-3 hours per day. Six judokas had sports qualifications of Candidate Master of Sports (CMS) and nine - of Master of Sports (MS); they trained all the year round for 20 hours per week.

Twenty 2^nd-4^th year students of the Faculty of Natural Sciences of Adyghe State University engaged in conventional motor activity (2 hours of physical education classes a week) comprised the control group on a voluntary basis. The testees were young men aged 17-20 years which corresponds to the middle adolescence according to the age periodization recommended by the Institute of Developmental Physiology of the Russian Academy of Education.

Results and discussion. Regardless of qualification and sports specialization, the strength of correlations does not change in student-non-athletes compared with students engaged in sports, but their lower numerical values are noted. This can be due to the considerably genetically predisposed specifics of processing of sensory information (amplitude-frequency characteristics of the EEG having a narrow reaction norm), as well as due to the ability to only enhancement of effectiveness of functioning of links of modally specified systems under the influence of systematic sports training sessions within the evolutionary fixed mechanisms of their interaction [2].

It has been determined that most of the detected significant correlations were moderate: so all students had a significant positive correlation between the N200 amplitude and the P3b latency period (decision speed). The data obtained suggest that, regardless of the modality of the used stimulus the decision speed is higher among those students who have less difficulty at the stage of identification. This can be explained by the fact that to the time required for decision making regarding the response actions can be reduced owing to the effective categorization of objects at this stage.

Positive correlation of moderate intensity was detected between the indices of identification (N200 latency) and recognition (Р3а latency) speed which is explained by the fact that both processes use limited resources of operative memory. This is especially noticeable when using complex multimodal signals [3, 4]. Positive correlation between the amplitude and latency of N200 is logical because a student, who had less difficulty (complexity) with identifying either exhibited or auditory stimulus (smaller N200 amplitude), spent less time on this stage of information processing.

No significant correlations between the amplitudes of N200 and Р3b indices, the N200 latency and the Р3b amplitude, as well as the latency of N200 (identification speed) and Р3b (decision speed) were detected, which is also similar to the data provided in the studies of B.V. Chernyshev et al [6].

 It should be noted that the data obtained in the present study with regards to the positive correlation of moderate intensity parameters such as the duration of N200–P300 intervals (volume and efficiency of the use of operative memory) with Р3b latency (decision speed) are consistent with the statement of V.V. Gnezditsky [4] that the Р3b latency is smaller when the volume of operative memory is bigger. As noted by several authors, shorter N200–P300 interval promotes larger volume and efficiency of operative memory usage [4, 6]. In light of the foregoing, it is logical that all the examined students, regardless of the mode of their motor activity, had a negative correlation of moderate intensity between the indices of N200–P300 intervals duration (the volume and efficiency of operative memory usage) and the Р3b amplitude (the complexity of decision making). However, the numerical values of intensity of the studied correlations of the students engaged in sports were higher than those of student-non-athletes. Ability to quickly focus on the task at hand while clearing the operative memory from irrelevant information and a high level of motivation of athletes to achieve good results may lie at the heart of this phenomenon.

Conclusions. The detected significant positive correlation of moderate intensity between the indices of the N200 amplitude and the P3b latent period, the N200 latency and the Р3а latency, the Р3b latency and duration of the N200-P300 intervals, as well as negative moderately intensive connections between the Р3b amplitude and duration of the N200-P300 intervals demonstrate contingency of structures and functional systems of the brain involved in different stages of the cognitive process. The students engaged in sports have closer correlations, which means an improvement of efficiency and coordination of various parts of specific modal systems under the influence of physical loads. The detected specifics of the correlations indicate that training of specific modal operative memory contributes to speed increase and reduction of complexity of a decision in a choice situation. Acceleration of decision making is directly related to the improvement of identification skills, which, in turn, is directly dependent on the speed of recognition of presented stimuli. Inclusion of exercises aimed at improving the skills of identification and recognition of stimuli of different modalities into the training plan of students engaged in sports will reduce the total reaction time and help them use reserves of speed increase that have not been involved before.

References

1. Bedanokova, L.Sh. The effect of physical load on cognitive functions of students / L.Sh. Bedanakova // Teoriya i praktika fizicheskoy kul'tury. – 2013. – № 8. – P. 50–54. (In Russian)
2. Мalykh, S.B. Genetic grounds of individual psychological differences: development and structure of psychological and psychophysical features: doctoral thesis (Psych.) / S.B. Malykh. – Мoscow, 2000. (In Russian)
3. Glezer, V.D. New data on the structure of visual identification / V.D. Glezer, A.A. Nevskaya // Bionics. – Мoscow, 1965. (In Russian)
4. Gnezditsky, V.V. Induced brain potentials in clinical practice / V.V. Gnezditsky. – Мoscow: Medpress-inform, 2003. – 264 P. (In Russian)
5. Zenkov, L.R. Clinical electroencephalography with elements of epileptology / L.R. Zenkov. – Мoscow: Medpress-inform, 2004. – 368 P. (In Russian)
6. Chernyshev, B.V. Manifestation of individual characteristics of temperament in behavioral parameters and cognitive induced potentials in the situation of attention / B.V. Chernyshev, V.E. Bezsonova, E.G. Chernysheva // Psikhologicheskiy zhurnal Mezhdunarodnogo universiteta prirody, obshchestva i cheloveka “Dubna". - 2011. - № 3. (In Russian)

Corresponding author: zabolotniy-tol1@yandex.ru