Nondual Awareness Study

Abstract

Introduction

Nondual awareness—the experiential dissolution of the subject-object boundary, in which experience is no longer split into a perceiver standing apart from what is perceived—is among the most consistently reported features of deep meditative states across contemplative traditions. In Zen it is approached through shikantaza, “just sitting”: an open, objectless practice that rests in awareness itself rather than concentrating on a chosen object. Its roots run deep—Dōgen made shikantaza central to Sōtō Zen, and the experience answers to the broader Mahāyāna understanding of śūnyatā, emptiness: the absence of any separate, independently existing self, of which the felt dissolution of the subject-object boundary is the lived, first-person expression. This study asks whether sustained shikantaza produces measurable—and crucially, durable—changes in neural oscillations, and whether those changes track that felt sense of nondual awareness.

The design is a single-subject longitudinal experiment combining consumer-grade EEG (Muse 2, raw 256 Hz) with a validated self-report instrument, the Nondual Awareness Dimensional Assessment (NADA; Hanley & Garland, 2018). Rather than tracking one continuous practice stream—where any improvement is confounded with time, mood, and day-to-day shifts in how the headband sits—it pairs two contrasts: an active baseline (shikantaza against a non-meditative silent-reading task) and an ABAB reversal (alternating blocks of practice and withdrawal). Together they separate the effect of meditating from ordinary seated cognition, and test whether changes persist once practice stops.

Three questions organize the work:

1. Does shikantaza elevate state nondual awareness relative to an ordinary, non-meditative baseline, and does that elevation grow with practice?
2. Which neural signatures accompany it? Frontal-midline theta and alpha are the primary, well-measured candidates, and gamma phenomena are treated cautiously as exploratory.
3. Do gains consolidate into trait-level shifts that persist through withdrawal?

Background

The broad reviews—Tang, Hölzel & Posner (2015), Cahn & Polich (2006), and Fox et al. (2016)—survey the field; the themes below give the specific grounding for each design choice.

EEG signatures of meditation

Across traditions, the most reliable electrophysiological correlates of meditation are increases in frontal-midline theta and in alphapower; effects in delta, beta, and gamma are inconsistent between studies (Cahn & Polich, 2006; Lomas et al., 2015; Lee et al., 2018). Lomas and colleagues, synthesizing 56 studies, found alpha and theta enhancement to be the clearest signal and explicitly noted the absence of consistent gamma effects. This is the empirical basis for treating theta and alpha as the study’s primary, well-measured outcomes (H2) and gamma as exploratory (H4).

Styles of practice and their signatures

Meditation is not a single, well-defined practice. Lutz, Slagter, Dunne & Davidson (2008) draw the now-standard distinction between focused attention (FA), which sustains a chosen object, and open monitoring (OM), which rests in non-reactive awareness of whatever arises; Travis & Shear (2010) add automatic self-transcending as a third family, each with a different oscillatory profile (Brandmeyer, Delorme & Wahbeh, 2019). Shikantaza is an open-monitoring practice, and this study reads its signatures against that taxonomy. The comparison condition here is deliberately non-meditative—silent reading—so that the primary contrast isolates meditating as such from ordinary cognition; separating open monitoring from focused attention is left to a possible later arm.

Gamma and the long-term practitioner

The most striking high-frequency finding is Lutz et al. (2004), in which long-term Tibetan practitioners self-induced high-amplitude gamma synchrony; gamma changes have since been linked to alterations in the sense of boundaries (Berkovich-Ohana et al., 2012). But these used research-grade EEG with careful artifact control. On a consumer frontal montage, the gamma band overlaps the spectrum of forehead and jaw EMG, so apparent gamma can be muscle rather than brain—which is why the gamma hypotheses here are exploratory and gated on EMG-aware artifact rejection.

Nondual awareness, the self, and its measurement

Nondual awareness has increasingly been treated as a tractable scientific target. Josipovic (2014) links it to the balance between intrinsic (default-mode) and extrinsic networks; Dor-Ziderman et al. (2013) used MEG to tie the dissolution of the narrative self to frontal changes; Brewer et al. (2011) and Garrison et al. (2013) connect experienced practice and “effortless awareness” to reduced posterior-cingulate/default-mode activity. To keep the construct measurable rather than impressionistic, this study uses the validated Nondual Awareness Dimensional Assessment (Hanley, Nakamura & Garland, 2018); broader conceptual framing follows Millière et al. (2018) and Thompson (2015).

Inference from a single subject

Davidson & Kaszniak (2015) catalogue the field’s methodological hazards— expectancy and demand effects, reliance on unvalidated self-report, weak controls— which are sharper still when the experimenter is also the subject. The defenses adopted here are deliberate: a validated instrument, a pre-registered split between confirmatory and exploratory tests, an active non-meditative baseline, and randomized phase timing analyzed with a randomization test, which provides valid inference for a single case without distributional assumptions (Kratochwill & Levin, 2010). Cross-frequency coupling is computed by the standard modulation-index method (Tort et al., 2010). The aim is not to generalize across people but to characterize one nervous system densely and honestly.

Methodology

Design

Two complementary contrasts support the inference. The first is a within-day active baseline: each day’s shikantaza sitting is compared against the same morning’s short reading session—an ordinary, non-meditative reference. Reading is used in place of passive rest, which an experienced practitioner readily slips into a meditative state; the contrast therefore isolates the effect of meditating from that of ordinary seated cognition.

The second is an ABAB reversal for durability. Blocks alternate between A (active practice) and B (withdrawal, formal sitting paused). A change that rises in A and reverses in B is practice-driven; a gain that persists through the following B is durable. The timing of the phase changes is randomized in advance, which licenses a randomization test—valid inference from a single subject, grounded in the random schedule itself rather than in assumptions about how the data are distributed (such as normality). Block length favors several shorter blocks over a few long ones: more phase transitions enlarge the randomization reference set and raise the test’s power, bounded only by allowing each B block enough time for state effects to wash out.

Standardization. Sessions are held at a consistent time and posture. A brief pre-session log records covariates that plausibly move EEG—sleep, caffeine, time since waking, perceived stress—so they can be modeled rather than left as noise.

Session inclusion. A session enters the confirmatory analyses only if signal quality clears a pre-set threshold (HSI fit and a maximum proportion of artifact-flagged epochs) and the sitting reaches full duration. Excluded sessions are retained and reported, never silently dropped.

Measures

Neural. Raw EEG is recorded at 256 Hz and processed locally. Because absolute power is unstable across days on a consumer headband, the confirmatory measures are relative (band power as a fraction of total) and log-transformed, compared between conditions (shikantaza vs reading) and across phases (A vs B).

Gamma is recorded but treated cautiously: frontal electrodes pick up forehead and jaw muscle activity in the same frequency range, so gamma findings are reported as exploratory with explicit artifact controls.

Phenomenological. NADA state and trait scores (above), plus per-session exploratory ratings of dimensions the NADA does not isolate:

• Effortlessness/non-striving
• Sense of unity/boundary dissolution
• Timelessness
• Bliss/equanimity
• Overall session quality

Hypotheses

Three primary hypotheses are confirmatory; three exploratory hypotheses probe mechanism and are interpreted more cautiously. Each is accompanied by a continuously updated estimate—a posterior point estimate with a 95% credible interval—whose precision increases as sessions accumulate.

Results

Daily medians for the five oscillation bands, tracked over the study. Per-hypothesis estimates appear in the cards above; this overview shows the underlying signal as it accumulates. The same graph anchors the meditation landing page and the data log.

And the direction of each band so far—an exploratory trend on the current sample, shown to exercise the analysis, not yet a confirmatory test:

Analysis Plan

The analysis is Bayesian. Each hypothesis is summarized by a posterior distribution over its effect, reported as a posterior point estimate and 95% credible interval. As observations accumulate the posterior concentrates and the interval contracts, so each effect is estimated with increasing precision rather than re-decided with every new session. Time series are modeled with autoregressive (AR(1)) errors, since consecutive days are correlated and ignoring that would overstate precision.

The design yields three estimands. Within-day contrasts (shikantaza vs the reading baseline) isolate the effect of meditating from ordinary cognition. Phase contrasts (A vs B), evaluated with a randomization test on the pre-randomized phase timing, test practice-specificity across the reversal. Durability is the persistence of an A-block gain into the following B block—an asymmetry between acquisition and reversal.

• Confirmatory tests are limited to the three primary hypotheses, fixed in advance; everything else is exploratory and flagged as hypothesis-generating.
• A minimum number of sessions per phase is required before any effect is interpreted, to avoid reading noise from sequential peeking.
• Neural–phenomenological associations (H5) are screened across the correlation matrix with multiplicity control and reported as exploratory.
• Carryover (H6) is modeled with the prior day’s value included, so a same-day signal is separated from ordinary day-to-day persistence.
• Sensitivity checks: relative vs absolute power, artifact-threshold choices, and covariate adjustment (sleep, caffeine, stress).

The full analysis code and the cleaned datasets are versioned alongside the site, so every figure on this page is reproducible from the raw recordings.

Hardware

Muse 2 (InteraXon, model MU-06): a 4-channel consumer EEG headband. Electrodes at TP9, AF7, AF8, TP10 per the 10–20 international system, sampling at 256 Hz. Sessions are captured as raw EEG via Mind Monitor(iOS); the raw signal—rather than only the app’s band-power summaries—is what makes coupling and connectivity measures possible.

Limitations are taken seriously: a consumer device with four frontal/temporal electrodes, susceptibility to motion and muscle artifact, and limited spatial resolution. It is well suited to longitudinal within-subject tracking of oscillatory trends, and poorly suited to source localization or fine spatial claims—which this study does not make.

References

• Tang, Y.-Y., Hölzel, B. K., & Posner, M. I. (2015). The neuroscience of mindfulness meditation. Nature Reviews Neuroscience.
• Cahn, B. R., & Polich, J. (2006). Meditation states and traits: EEG, ERP, and neuroimaging studies. Psychological Bulletin.
• Lomas, T., Ivtzan, I., & Fu, C. H. Y. (2015). A systematic review of the neurophysiology of mindfulness on EEG oscillations. Neuroscience & Biobehavioral Reviews.
• Lee, D. J., et al. (2018). Review of the neural oscillations underlying meditation. Frontiers in Neuroscience.
• Fox, K. C. R., et al. (2016). Functional neuroanatomy of meditation: A review and meta-analysis of 78 functional neuroimaging investigations. Neuroscience & Biobehavioral Reviews.
• Brandmeyer, T., Delorme, A., & Wahbeh, H. (2019). The neuroscience of meditation: Classification, phenomenology, correlates, and mechanisms. Progress in Brain Research.
• Lutz, A., Slagter, H. A., Dunne, J. D., & Davidson, R. J. (2008). Attention regulation and monitoring in meditation. Trends in Cognitive Sciences.
• Travis, F., & Shear, J. (2010). Focused attention, open monitoring and automatic self-transcending: Categories to organize meditations from Vedic, Buddhist and Chinese traditions. Consciousness and Cognition.
• Josipovic, Z. (2014). Neural correlates of nondual awareness in meditation. Annals of the New York Academy of Sciences.
• Lutz, A., Greischar, L. L., Rawlings, N. B., Ricard, M., & Davidson, R. J. (2004). Long-term meditators self-induce high-amplitude gamma synchrony during mental practice. PNAS.
• Berkovich-Ohana, A., Glicksohn, J., & Goldstein, A. (2012). Mindfulness-induced changes in gamma band activity — implications for the default mode network, self-reference and attention. Clinical Neurophysiology.
• Dor-Ziderman, Y., Berkovich-Ohana, A., Glicksohn, J., & Goldstein, A. (2013). Mindfulness-induced selflessness: A MEG neurophenomenological study. Frontiers in Human Neuroscience.
• Brewer, J. A., et al. (2011). Meditation experience is associated with differences in default mode network activity and connectivity. PNAS.
• Garrison, K. A., et al. (2013). Effortless awareness: Using real-time neurofeedback to investigate correlates of posterior cingulate cortex activity in meditators' self-report. Frontiers in Human Neuroscience.
• Hanley, A. W., Nakamura, Y., & Garland, E. L. (2018). The Nondual Awareness Dimensional Assessment (NADA): New tools to assess nondual traits and states of consciousness. Psychological Assessment.
• Davidson, R. J., & Kaszniak, A. W. (2015). Conceptual and methodological issues in research on mindfulness and meditation. American Psychologist.
• Kratochwill, T. R., & Levin, J. R. (2010). Enhancing the scientific credibility of single-case intervention research: Randomization to the rescue. Psychological Methods.
• Tort, A. B. L., et al. (2010). Measuring phase-amplitude coupling between neuronal oscillations of different frequencies. Journal of Neurophysiology.
• Millière, R., et al. (2018). Psychedelics, meditation, and self-consciousness. Frontiers in Psychology.
• Thompson, E. (2015). Waking, Dreaming, Being. Columbia University Press.