Cognitive Behavior Evaluation Based on Physiological Parameters among Young Healthy Subjects with Yoga as Intervention

Abstract

Objective. To investigate the effect of yoga practice on cognitive skills, autonomic nervous system, and heart rate variability by analyzing physiological parameters. Methods. The study was conducted on 30 normal young healthy engineering students. They were randomly selected into two groups: yoga group and control group. The yoga group practiced yoga one and half hour per day for six days in a week, for a period of five months. Results. The yoga practising group showed increased α, β, and δ EEG band powers and significant reduction in θ and γ band powers. The increased α and β power can represent enhanced cognitive functions such as memory and concentration, and that of δ signifies synchronization of brain activity. The heart rate index θ/α decreased, neural activity β/θ increased, attention resource index β/(α + θ) increased, executive load index (δ + θ)/α decreased, and the ratio (δ + θ)/(α + β) decreased. The yoga practice group showed improvement in heart rate variability, increased SDNN/RMSSD, and reduction in LF/HF ratio. Conclusion. Yoga practising group showed significant improvement in various cognitive functions, such as performance enhancement, neural activity, attention, and executive function. It also resulted in increase in the heart rate variability, parasympathetic nervous system activity, and balanced autonomic nervous system reactivity.

Yoga research review

“…In a randomized controlled trial, the yoga group versus the control group showed reduced work-related stress and a significant increase in heart rate variability (vagal activity) following a 12-week program [146]. In a five-month program (90 min per day 6 days per week) the yoga group versus a control group showed a significant increase in heart rate variability (vagal activity) and a reduction in the LF/HF ratio [147]. The yoga group also showed increased alpha, beta and theta EEG band powers and a reduction in delta band power suggesting enhanced memory and concentration and synchronization of brain activity.…”

Yoga in school sports improves functioning of autonomic nervous system in young adults: A non-randomized controlled pilot study

“…A study also published in 2015 by Nagendra et al investigated the effects of yoga on the cognitive ability, autonomic nervous system and heart rate variability (HRV)-measured by means of electroencephalography (EEG) and echocardiography (ECG) recordings-in engineering students. They found significant improvements in several cognitive functions-including memory, neuronal activity and alertness-and alterations in HRV tending towards parasympathetic dominance [18].…”

Combining electroencephalographic activity and instantaneous heart rate for assessing brain–heart dynamics during visual emotional elicitation in healthy subjects

“…As a general approach, previous studies have tried to link the EEG power in specific bands to HRV measures. Although significant correlations were found for the α (8-12 Hz) [48][49][50][51][52], β (13-30 Hz) [49,50,53] and γ (>30 Hz) bands [53,54], the psychophysiological meaning of such associations is still ill-defined. For instance, complexity of HRV series was used to predict changes in the EEG α band after stress [48].…”