Performance in the Stroop Task and Simultaneously Recorded Heart Rate Variability before and after Meditation, Supine Rest and No -Intervention

In an earlier study heart rate variability (HRV) recordings after cyclic meditation (CM) suggested a shift towards vagal dominance. In a separate study, CM improved the performance in a task for attention. Generally, attention tasks result in sympathetic activation. The present study was intended to assess whether CM would change the autonomic status when practitioners performed an attention task, with simultaneous HRV recording Methods: Twenty-five male volunteers with group average age ± S.D., 23.9 ± 5.0 years were each assessed on three separate days in three sessions, (i) CM, (ii) supine rest (S R), and (iii) quiet sitting (QS). Each session was for 23 minutes. Simultaneous assessments were made before and after each of the three sessions and included the HRV, respiratory rate and performance in the Stroop task. Results: Following CM the LF power increased and HF power decreased (P < 0.05). There was an increase in the word scores, color scores and color-word scores of the Stroop task (P < 0.001, Repeated measures ANOVA, followed by Bonferroni adjusted post-hoc analyses). Conclusion: The results suggest that there was reduced parasympathetic activity after CM and possibly increased sympathetic activity, when participants simultaneously performed the Stroop task. Their improved performance in the Stroop task suggests better response inhibition, interference resolution, word reading and activation along with reduced physiological arousal based on HF power of the HRV.