scholarly journals The typology of mechanisms of adaptation to the cognitive load on the variability of heart rate dynamics

2018 ◽  
Vol 11 (3) ◽  
pp. 78-93
Author(s):  
I.G. Bodrov ◽  
A.Yu. Shishelova

While analyzing heart rate variability there were detected two types of visceral adaptation to cognitive activities: the first one is characterized by decrease of tension index (Baevskiy, 1984) and increase of heart rate variability at a cognitive load, along with increased power of regulatory effects on the heart rate; the second one is defined by higher heart rate variability, higher power of regulatory effects before the cognitive load and increase of the strain index during cognitive load in the absence of other significant changes. It is peculiar for people related to these types to possess different correlation relationships between the indices of sensory-motor reactions and heart rate variability.

2018 ◽  
Vol 28 (3) ◽  
pp. 298-306 ◽  
Author(s):  
David M. Garner ◽  
Franciele Marques Vanderlei ◽  
Luiz Carlos Marques Vanderlei

Introduction: Heart rate variability (HRV) can be assessed from RR-intervals. These are derived from an electrocardiographic PQRST-signature and can deviate in a chaotic or irregular manner. In the past, techniques from statistical physics have allowed researchers to study such systems. Objective: This study planned to assess the heart rate dynamics in young obese subjects by nonlinear metrics to heart rate variability. Methods: 86 subjects were split equally according to status. Heart rate was recorded with the subjects resting in a dorsal (prone) position for 30 minutes. The complexity of the RR-intervals was assessed by five Entropies, Detrended Fluctuation Analysis, Higuchi and Katz’s fractal dimensions Following inconclusive tests of normality we calculated the One-Way Analysis of Variance, Kruskal-Wallis, and the Effect Sizes by Cohen’s d significances. Results: It was established that Shannon, Renyi and Tsallis Entropies and the Higuchi and Katz・s fractal dimensions could significantly discriminate the two groups. The three entropies were higher in obese youths, suggesting less predictable sets of RR intervals (p<0.0001; d≈1.0). Whilst the Higuchi (p<0.003; d≈0.76) and Katz・s (p≈0.02; d≈0.57) fractal dimensions were lower in obese youths. Conclusion: As with chaotic globals an increase in response was detected by three measures of entropy in young obese. This is counter to the decreasing response detected by fractal dimensions. Chaotic globals and entropies are more dependable than fractal dimensions when assessing the responses to obesity.


Author(s):  
O.V. Kiyok ◽  
V.M. Pokrovskiy

The impact of specific factors on students during workshop practice results in tension of regulatory and adaptive mechanisms. This fact can be estimated according to the heart rate variability (HRV). It is of the integral indicators reflecting all mechanisms of cardiac regulation. The aim of the study is to assess students’ adaptive capacity during workshop training based on HRV. Materials and Methods. The authors divided 30 students into two groups: a group of less adapted and a group of more adapted students. J. Strelau’s theory on temperament and H. Eysenck's personality types were used for the purpose. The authors studied heart rate variability at the beginning and at the end of workshop practice. Statistika 6.0 for Windows was used to process the results. Results. The authors distinguished differences in HRV in two study groups. Before practice, the regulatory system tension index was 479.64 in the group of less adapted students. It was 106.86 in the group of more adapted students. The total power (ms2) indicating adaptive capacity was by 80.9 % higher in more adapted students. After workshop practice, changes in the tonus of the autonomic nervous system were observed in both study groups. However, in the group of less adapted students, indicators confirming sympathicotonia and a decrease in heart rate variability changed to a greater degree. Thus, tension index in the group of more adapted students increased by 46.7 %, and in the group of less adapted students – by 209.9 %. The authors also observed a decrease in the total power: in more adapted students by 51.3 %, and in the less adapted students by 54.3 %. Results. Analysis of HRV showed a more evident adverse influence of workshop practice on less adapted students. Keywords: students, workshop practice, heart rate variability. Воздействие специфических факторов на учащихся при прохождении производственной практики приводит к напряжению регуляторно-адаптивных механизмов, что можно оценить по вариабельности ритма сердца (ВРС) – одному из интегральных показателей, отражающих механизмы сердечной регуляции на всех уровнях. Цель исследования. Оценить адаптивные возможности учащихся при прохождении производственной практики по показателям ВРС. Материалы и методы. У 33 учащихся, разделенных согласно теории Я. Стреляу и в соответствии с психологическими типами личности по Айзенку на группы менее адаптированных и более адаптированных, изучили вариабельность ритма сердца в начале и конце производственной практики. Для обработки результатов исследования применяли программу Statistika 6,0 for Windows. Результаты. Установлены различия ВРС в двух исследуемых группах. До практики индекс напряжения регуляторных систем (ИН) в группе менее адаптированных составил 479,64, в группе более адаптированных учащихся – 106,86. Общая мощность спектра ТР (мс2), свидетельствующая об адаптивных возможностях, у более адаптированных учащихся была выше на 80,9 %. После производственной практики изменения тонуса вегетативной нервной системы отмечены в обеих исследуемых группах. Однако в группе менее адаптированных учащихся показатели, свидетельствующие о симпатикотонии и уменьшении вариабельности ритма сердца, изменились в большей степени. Так, ИН в группе более адаптированных учащихся увеличился на 46,7 %, а в группе менее адаптированных – на 209,9 %. Отмечено уменьшение общей мощности спектра: у более адаптированных на 51,3 %, у менее адаптированных на 54,3 %. Выводы. На основании анализа ВРС показано более выраженное неблагоприятное влияние производственной практики на менее адаптированных учащихся. Ключевые слова: учащиеся, производственная практика, вариабельность ритма сердца.


2021 ◽  
Author(s):  
Renaldo D. Moreno ◽  
Natália P. Moreno-Mantilla ◽  
Marcos V. M. Lima ◽  
Mauro J. D. Morais ◽  
Vitor E. Valenti ◽  
...  

Abstract Blindness affect the daily life activities and the causes and prevalence are different worldwide. This study aimed to investigate the pattern of the autonomic nervous system modulation on the heart in blind and normal vision subjects submitted acutely to low vision. Normal vision (NV) subjects (N = 32) and blind patients (N = 24) were submitted to HRV analysis during resting, intervention and recovery periods. Intervention consisted of handling objects, short walking, and cognitive activities performed with pedagogic games while using sleeping masks. No difference was observed in indexes in the time and frequency domain, and in the geometric indexes comparing blind and NV subjected to acute low vision during resting and recovery. Nevertheless, during intervention, RMSSD, pNN50, and SD1were found lower in blind than in NV subjects. Therefore, blind patients showed similar HRV at resting or upon possible stressful challenges compared to NV subjects acutely subjected to low vision, indicating absence of differences in the cardiovascular risk between groups. In addition, blind patients show a smaller reduction in parasympathetic modulation on the heart during possible stressful challenges than NV individuals submitted to low vision, which is likely an important physiological adaptation for an adequate function of the cardiovascular system in blindness.


Author(s):  
E.A. Archibasova ◽  
◽  
V.Yu. Kulikov ◽  
M.I. Voevoda ◽  
◽  
...  

With different variants of cognitive load, the corresponding regions of the brain are activated, which is manifested by peculiarities of heart rate variability (HRV). Cognitive load (semantic fluency) contributes to a decrease in the activity of the Total Power (TP) integral indicator in the group as a whole. The use of the autonomic balance index (ABI), which is an objective indicator of the autonomic mechanisms of HRV regulation, reveals that this load is most sensitive for young men, who have more vulnerable parasympathetic NS, while girls do not have such a reaction. When performing the semantic fluency test under conditions of cognitive load (reverse counting), an increase in the TP index was noted. When comparing ABI between groups of boys and girls before the exercise, a significantly higher ABI in girls is noted, that is initially the contribution of the parasympathetic NS to the regulation of HRV is of predominant importance. After the exercise, the ABI in girls decreases which indicate the predominant role of the sympathetic NS as a mechanism for regulating the HRV in response to cognitive load — the ability to count. The development of an imbalance between the sympathetic and parasympathetic NS activity under conditions of cognitive load reveals the most vulnerable regulatory circuits, which may become the basis of the corresponding pathological process in the future.


2019 ◽  
Vol 125 ◽  
pp. 107-116 ◽  
Author(s):  
Delphine Meier-Girard ◽  
Edgar Delgado-Eckert ◽  
Emmanuel Schaffner ◽  
Christian Schindler ◽  
Nino Künzli ◽  
...  

1978 ◽  
Vol 22 (1) ◽  
pp. 507-507
Author(s):  
James L. Knight ◽  
Gavriel Salvendy ◽  
Gary Endicott ◽  
Barbara Basila ◽  
Joseph Sharit

Heart rate variability often decreases with increased cognitive load (Kalsbeek, 1971). Studies (Manenica, 1977) varying task pacing requirements unexpectedly revealed decreased SA in self-pacing (self-controlled intra-task event timing) compared to external-pacing (experimenter- or apparatus-controlled event timing). But why should self-pacing ever involve higher cognitive load? Since Ss must time events and otherwise monitor and structure their own performance in self- but not external-pacing, perhaps these responsibilities lead to higher cognitive load in self-pacing when work-rates are equated between self-and externally-paced conditions. Two experiments were conducted to examine possible sources of cognitive load in self-pacing. In Experiment II, an attempt was made to reduce cognitive load by providing new sources of extrinsic feedback on a visual display. In both studies physical work load was held constant across experimental conditions.


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