Objectives: In ancient yoga texts there are two meditative states described. One is dharana, which requires focusing, the second is dhyana, during which there is no focusing, but an expansive mental state is reached. While an earlier study did show improved performance in an attention task after dharana, the autonomic changes during these two states have not been studied. Methods: Autonomic and respiratory variables were assessed in 30 healthy male volunteers (group mean age -SD, 29.1 -5.1 years) during four mental states described in traditional yoga texts. These four mental states are random thinking (cancalata), nonmeditative focusing (ekagrata), meditative focusing (dharana), and effortless meditation (dhyana). Assessments were made before (5 minutes), during (20 minutes), and after (5 minutes), each of the four states, on four separate days. Results: During dhyana there was a significant increase in the skin resistance level ( p < 0.001; post hoc analysis following ANOVA, during compared to pre) and photo-plethysmogram amplitude ( p < 0.05), whereas there was a significant decrease in the heart rate ( p < 0.001) and breath rate ( p < 0.001). There was a significant decrease in the low frequency (LF) power ( p < 0.001) and increase in the high frequency (HF) power ( p < 0.001) in the frequency domain analysis of the heart rate variability (HRV) spectrum, on which HF power is associated with parasympathetic activity. There was also a significant increase in the NN50 count (the number of interval differences of successive NN intervals greater than 50 ms; p < 0.001) and the pNN50 (the proportion derived by dividing NN50 by the total number of NN intervals; p < 0.001) in time domain analysis of HRV, both indicative of parasympathetic activity. Conclusions: Maximum changes were seen in autonomic variables and breath rate during the state of effortless meditation (dhyana). The changes were all suggestive of reduced sympathetic activity and/or increased vagal modulation. During dharana there was an increase in skin resistance. The changes in HRV during ekagrata and cancalata were inconclusive.

Mid-latency auditory evoked potentials (MLAEPs) were assessed in 60 participants during 4 mental states described in traditional yoga texts. These 4 mental states are random thinking, nonmeditative-focused thinking, meditative focusing, and meditation. Assessments were made before (5 minutes), during (20 minutes), and after (5 minutes) each of the 4 states, on 4 separate days. There were prolonged latencies of 2 MLAEPs components, the Na and Pa waves during meditation (P < .05, post hoc analyses following analysis of variance [ANOVA]), suggesting that auditory information transmission at the level of the medial geniculate and primary auditory cortex (ie, the neural generators corresponding to the Na and Pa waves) was delayed. Hence, meditation influenced MLAEPs, while meditative focusing did not.

Meditation is currently considered to be associated with increased awareness. In ancient yoga texts, two separate meditative states have been described. These are meditative focusing (dharana) and a state of mental expansiveness (dhyana). Two more mental states are described in another yoga text. These are random thinking (cancalata) and focusing while not in meditation (ekagrata). The physiological effects of these states have been assessed using autonomic variables, evoked potentials, functional magnetic resonance imaging, and performance in a cancellation task. The findings suggest that dhyana is associated with reduced sympathetic activity and increased vagal tone, whereas dharana does indeed improve performance in an attention task. Hence, correlating findings from ancient texts with contemporary science can be useful.

Background and Objective: Attention and memory are essential aspects of cognitive health. Yogasanas, pranayama, and meditation have shown to improve cognitive functions. There has been no assessment of Trataka (yogic visual concentration) on working or on spatial memory. The present study was planned to assess the immediate effects of Trataka and of eye exercise sessions on the Corsi-block tapping task (CBTT).Methods: A total of 41 healthy volunteers of both genders with age 23.21 ± 2.81 years were recruited. All participants underwent baseline assessment, followed by 2 weeks of training in Trataka (including eye exercise). Each training session lasted for 20 min/day for 6 days a week. After completion of the training period, a 1-week washout period was given. Each participant then was assessed in two sessions in Trataka and in eye exercise on two separate days, maintaining the same time of the day. Repeated measure analysis of variance with Holm’s adjustment was performed to check the difference between the sessions.Results: Significant within-subjects effects were observed for forward Corsi span andforward total score (p &lt; 0.001), and also for backward Corsi span (p &lt; 0.05) and backward total score (p &lt; 0.05). Post hoc analyses revealed Trataka session to be better than eye exercises and baseline. The eye exercise session did not show any significant changes in the CBTT.Conclusion: The result suggests that Trataka session improves working memory, spatial memory, and spatial attention.

BACKGROUND: The prolonged usage of digital displays leads to visual strain and, in turn, impairs psychological well-being. The practice of Yoga is said to enhance psychological functions and reduce visual strain. OBJECTIVE: The present study assessed the effect of the trataka (Yogic visual concentration) practice on the visual strain, mind-wandering, and mindfulness. METHODS: One hundred six volunteers equally distributed in the experimental and control groups completed the study. Visual Fatigue Scale (VFS), visual symptoms checklist (VSC), mind-wandering questionnaire (MWQ), and State Mindfulness Attention Awareness Scale (SMAAS) were administered at baseline and at the end of two weeks. RESULTS: All variables were similar at the baseline in both groups, and significant differences were noted at the end of two weeks between both groups. There was a significant reduction in VFS and VSC scores, MWQ, along with an increase in SMAAS scores in the experimental group. Although there were significant changes in VFS, MWQ, and SMAAS in the control group, the magnitude of change was minimal. CONCLUSIONS: The practice of trataka was found to reduce the visual strain, mind wandering while improving the state mindfulness. The practice can be implemented to mitigate visual strain and associated psychological implications due to prolonged exposure to digital displays, which has increased during the COVID-19 pandemic.

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