Age-related Neurophysiological Changes in Simple Sensorimotor Reaction Performance

Abstract

Introduction.For different types of professional activity, the speed of information processing is one of the most important indicators of performance. It is well known that aging is accompanied by changes in the speed and / or mode of information processing in the brain. Simple sensorimotor reaction (SMR) shows speed and efficiency of information perception processes, its integration and is and reveals how well the basic cognitive mechanisms can be involved in the implementation of target tasks. Purpose.The aim of this work was to investigate the rate of SMR in different age groups and to identify age-related changes in neural networks that promote task performance.Methods.The survey involved 34 right-handed volunteers, aged 18-54, without health complaints - representatives of various military professions (mechanics, shooters, drivers, radar operators, anti-aircraft missile officers, communications, tablets, pilots and conscripts), which were divided into three age groups (1 group - 18-23 years, n = 11; 2 group - 24-34 years, n = 15; 3 group - 35- 54 years, n = 8). SMR was determined using a specialized computer program and while its performance 19 electrode EEG was recorded. Remote synchronization of brain areas was determined using coherent analysis in Neuron-Spectrum-4 / VP complex («NeuroSoft»). Reliable synchronization was determined only for those pairs of leads for which the median was ≥ 0.7.Results.Although the comparative analysis of the PSMR rate in the three groups according to the Kruskal-Wallis test did not reveal significant differences (Kruskal-Wallis test: H (2, N = 54) = 0.889; p = 0.64), coherent analysis of electroencephalograms, which were recorded during task, revealed that there were differences in the neural mechanisms of SSMR between the three age groups. We showed age-related increases in activation of the left secondary visual cortex, while activation of the left frontal lobe decreasedwhich may indicate shift from the strategic system of response to the system of informative features selection and constant attention maintenance. In the third group coherence in the theta range between the prefrontal area and the postcentral gyrus was the strongest in comparison with the first and second groups, which may indicate an increase in the role of visual selective attention with age, as well as greater effort and concentration to perform the task. Also there was an age-related increase in the alpha range coherences and decrease in the delta range, which may indicate shift from the general setting to the input information flow to local highly specific information processing.Originality. Age-related adaptive changes of the neural networks that enable effective performance of the SSMR: different strategies of visual-motor reaction are revealed.72 Серія «Біологічні науки», 202 2Conclusions. Performance of the SSMR test involves different neuronal strategies that were determined for three age groups. The prospect of further research is to determine age-related differences in the chronometric indicators and neuronal mechanisms for SSMR, choice reaction and other psychophysiological tests for different military specialties and according to acquired data create guidelines for conducting surveys to ensure effective performance of work responsibilities with age. Key words: simple sensorimotor reaction; electroencephalogram; coherent analysis; age-related changes; professional selection