Acute effects of meditation training on the waking and sleeping brain: Is it all about homeostasis?
Level 3 - non-randomized controlled study
Non-randomized controlled comparative study
PubMed 30144201 · doi:10.1111/ejn.14131
What was done
High-density EEG recordings were acquired from 27 long-term meditators (LTM) and 31 meditation-naïve participants (MNP) at baseline and following two 8-hour sessions of either mindfulness or compassion-and-loving-kindness meditation. The authors assessed post-meditation changes in waking rest scalp power and analyzed their spatial and frequency correlations with previously observed NREM sleep EEG changes.
What was found
In LTM only, meditation led to increases in low and fast waking EEG oscillations peaking at 8 Hz and 15 Hz over prefrontal and left centro-parietal electrodes. There was no significant difference between meditation styles in LTM and no difference between matched sessions in MNP. Changes in waking EEG significantly correlated with NREM sleep EEG changes at low frequencies (<12 Hz), peaking in the theta-alpha range (4-12 Hz). No specific effect sizes, test statistics, or p-values were reported in the abstract.
Why it matters
The observed theta-alpha coupling across wakefulness and NREM sleep suggests meditation effects involve post-practice neural reverberation during sleep rather than standard slow-wave sleep homeostasis.
Limits
The study is a non-randomized comparison of self-selected long-term practitioners versus naïve controls with a modest total sample size (n = 58). Numerical effect sizes and statistical parameters were omitted from the abstract.
Cited by
- context In long-term meditators, high-amplitude gamma electrical activity is observed during slow-wave sleep superimposed on delta oscillations.