Quantitative EEG Analysis of Brain Activity Before, During, and After Nadi Shodhana Pranayama

Nadi Shodhana Pranayama, or alternate nostril breathing, is a yogic breathing technique believed to regulate the autonomic nervous system and improve attention. While previous studies have examined its neurophysiological effects, many rely on long-term interventions or do not include regional brain comparisons and effect-size analysis. This study evaluated the effects of a single Nadi Shodhana session on EEG brain-wave activity by analyzing Delta (0.5–4 Hz), Theta (4–8 Hz), Alpha (8–12 Hz), Beta (12–30 Hz), and Gamma (30–45 Hz) frequency bands. EEG data were collected from twelve participants (ten analyzed after signal-quality exclusions) using a wearable Muse-S headband before, during, and after practice. A custom Python pipeline using Welch power spectral density analysis quantified changes in relative band power. Results showed increased Theta and Delta activity during practice, accompanied by significant decreases in Beta and Gamma activity. Alpha power increased from 23.2% at baseline to 25.9% after practice (Cohen's d = 0.82). Despite individual variability, regional analyses demonstrated a consistent shift toward a relaxed yet attentive brain state, supporting wearable EEG as a practical tool for quantifying the neurophysiological effects of yogic breathing.