Background and aim: Subjective symptoms of Internet addiction (IA), such as interpersonal and health-related problems (IH-RP), do not correlate with objective physiological parameters. This study aimed to investigate the cardiovascular reactivity after physical exercise in 15–16-year-old adolescents showing different severities of symptoms of health-related problems due to Internet overuse.Methods: This study included 20 healthy adolescents (boys, 15–16 years) with different risks of IA (by the Chen internet addiction scale [CIAS]). The physical exercise test was to perform a standing broad jump three times. The arterial blood pressures and heart rates were recorded before, immediately after, and at 4 minutes of rest after exercise.Results and discussion: The total sample of adolescents was divided into two groups, that is, those with IH-RP scores of 12 or less (Group I, n = 12) and those scoring more than 12 points (Group II, n = 8). The diastolic blood pressure significantly increased after exercise in group II, whereas it remained stable in group I. The heart rate in group I tended to increase, but the changes were not statistically significant. Group II adolescents showed significant increases in heart rate, and at rest, this parameter was significantly higher than the baseline value.Conclusions: Adolescents with a risk of IA and severe symptoms of interpersonal and health-related problems had increased sympathetic activity during and after speed-strength physical exercise compared to those without the aforementioned symptoms.

Internet-dependent behaviour in adolescents can contribute to a change in the function of the nervous system, which is reflected in the violation of time perception and autonomic regulation of the heart rate. The aim of the study was to determine groups of individuals with different risks of Internet addiction (IA) in relation to heart rate variability (HRV) parameters and the efficiency of time estimation in adolescents aged 16–17 years living in the Russian Arctic. Adolescents aged 16–17 years (n = 49–32 females, 17 males) living in Yamalo-Nenets Autonomous Okrug (Russia) were observed. Chen Scale Internet Addiction (CIAS) was used. The duration of an individual 1 min was determined. HRV parameters were determined using the "Varicard" equipment (Russia). In 16–17-year-old adolescents with different levels of risk of developing IA, including signs of IA, we revealed a high severity of symptoms of withdrawal from Internet use, difficulty in time estimation against the background of sympathicotonia and a decrease in vagal regulation of heart rate. In individuals with minimal symptoms of withdrawal from Internet use, the total HRV and vagal activity remain higher than in those with severe withdrawal symptoms, and their time estimation remains effective.

The aim of the study was to assess different combinations of time estimation ability and heart rate variability (HRV) parameters in adolescents during developing of Internet addiction (IA). The study included adolescents aged 16–17 (n = 49) living in the southern region of Russia. IA was measured using the Chen Internet Addiction Scale (CIAS). An individual minute test (IM) was performed, and HRV was recorded. There are three groups that differ in HRV, IM duration and CIAS parameters. Minimal and moderate risk of IA development was detected against a background of a tendency towards vagotonia and prolonged IM time (Group I) and balanced autonomic nervous balance and optimal IM time (Group II). A balanced autonomic nervous balance and prolonged IM time were detected in the group of persons with a moderate risk of IA and a stable IA pattern (Group III). We assume that the development of IA in adolescents may be carried out by different neural mechanisms, including optimal autonomic nervous balance, but with primary impairment of cortical brain mechanisms of time perception.

The neurophysiological correlates of certain types of cognitive impairment in relation to the spatial pattern of auditory cognitive evoked-related potentials (ERPs) in hypertensive persons remain unclear. The aim of this study was to determine the parameters of ERPs (N200, P300) in impaired different domains (visuospatial/executive and memory) of cognitive function in arterial hypertension, including cardiovascular ischemic events. A total of 46 patients (65–84 years) were observed. The clinical diagnosis of vascular dementia, the Montreal Cognitive Assessment Scale (MoCA test) and the spatial pattern of ERPs (N200, P300) were the parameters used to identify three groups: the Control Group without cognitive impairment (n = 13), the group with a leading memory disturbance (Memory Group, n = 20) and the group with a leading visuospatial/executive disturbance (VS/E Group, n = 13). In persons belonging to the Memory Group, N2 latency was prolonged in the central (C3 C4) and right parietal (P4) brain parts; latency of the motor component (P300) may remain similar to that of the ControlGroup. In persons belonging to theVS/E Group, maximal prolonged recognition time (N2), especially in the left central (C3), frontal-midline (Fz), right parietal (P3) and temporal (P4) brain parts, was observed; P300 latency in the central-midline (Cz) and left anterior-temporal (F7) brain parts among all the groups was revealed.

The aim of the work was to determine the relationship of individual typological reactions of bioelectric activity of the brain, variability of the cardiac heart (HRV) when exposed to cold with the parameters of voluntary attention. EEG, HRV and body temperature were recorded in the heat, with short-term air cooling (-200C, 10 minutes) and after being in the cold. The evaluation of indicators of voluntary attention was performed using the Toulouse-Pieron test and included parameters such as speed, accuracy of the test and the number of errors. The results of the study revealed three variants of the formation of adaptive reactions in response to cold. The obtained results suggest that the best indicators of voluntary attention and the effectiveness of adaptive response to cold were observed with optimal interaction of the central and autonomic nervous systems. The correlation between the low speed of the test and the high accuracy and the tension of the regulatory systems of the body in response to cold with the predominance of the activity of the sympathetic nervous system and the high activity of the hypothalamic-diencephalic structures of the brain was found. The average speed of completing test tasks with a large number of errors reveals a relationship with insufficient resource mobilization in adapting to cold with a predominance of activity of the parasympathetic nervous system and an increase in the activity of subcortical structures of the brain. Thus, in the conditions of the North, individual variants of adaptive reactions in response to cold have been identified, associated with various neurophysiological mechanisms of mobilization of functional systems and indicators of the level of voluntary attention.