RESEARCH ARTICLE
The Minimal Phenomenal Experience
questionnaire (MPE-92M): Towards a
phenomenological profile of “pure
awareness” experiences in meditators
Alex GammaID
1☯*, Thomas Metzinger2☯*
1 Research Department, University Hospital of Psychiatry, Zu rich, Switzerland, 2 Arbeitsbereich
Theoretische Philosophie, Philosophisches Seminar, Johannes Gutenberg University, Mainz, Germany
☯ These authors contributed equally to this work.
* alex.gamma@uzh.ch (AG); metzinger@uni-mainz.de (TM)
Abstract
Objective
To develop a fine-grained phenomenological analysis of “pure awareness” experiences in
meditators.
Methods
An online survey in five language versions (German, English, French, Spanish, Italian) collected
data from January to March 2020. A total of 92 questionnaire items on a visual analogue
scale were submitted to exploratory and confirmatory factor analysis.
Results
Out of 3627 submitted responses, 1403 were usable. Participants had a median age of 52
years (range: 17–88) and were evenly split between men and women (48.5% vs 50.0%).
The majority of meditators practiced regularly (77.3%), were free of diagnosed mental disorders
(92.4%) and did not regularly use any psychoactive substances (84.0%). Vipassana
(43.9%) followed by Zen (34.9%) were the most frequently practiced meditation techniques.
German (63.4%) and English (31.4%) were by far the most frequent questionnaire languages.
A solution with 12 factors explaining 44% of the total variance was deemed optimal
under joint conceptual and statistical considerations. The factors were named “Time, Effort
and Desire,” “Peace, Bliss and Silence,” “Self-Knowledge, Autonomous Cognizance and
Insight,” “Wakeful Presence,” “Pure Awareness in Dream and Sleep,” “Luminosity,”
“Thoughts and Feelings,” “Emptiness and Non-egoic Self-awareness,” “Sensory Perception
in Body and Space,” “Touching World and Self,” “Mental Agency,” and “Witness Consciousness.”
This factor structure fit the data moderately well.
Conclusions
We have previously posited a phenomenological prototype for the experience of “pure
awareness” as it occurs in the context of meditation practice. Here we offer a tentative 12-
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Citation: Gamma A, Metzinger T (2021) The
Minimal Phenomenal Experience questionnaire
(MPE-92M): Towards a phenomenological profile
of “pure awareness” experiences in meditators.
PLoS ONE 16(7): e0253694. https://doi.org/
10.1371/journal.pone.0253694
Editor: Jane Elizabeth Aspell, Anglia Ruskin
University, UNITED KINGDOM
Received: November 4, 2020
Accepted: June 11, 2021
Published: July 14, 2021
Peer Review History: PLOS recognizes the
benefits of transparency in the peer review
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https://doi.org/10.1371/journal.pone.0253694
Copyright: 2021 Gamma, Metzinger. This is an
open access article distributed under the terms of
the Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: The data,
documentation and all language versions of the
MPE-92M questionnaire are publicly available as a
factor model to describe its phenomenal character in a fine-grained way. The current findings
are in line with an earlier study extracting semantic constraints for a working definition
of minimal phenomenal experience.
Introduction
The concept of “pure consciousness” or “pure awareness” has a long tradition in the literature
on contemplative practices. It refers to the meditator’s subjective experience of consciousness
as such, wherein he or she is non-conceptually aware of being aware. Pure awareness is often
described as a contentless form of experience, and it has played a great role in Eastern philosophical
traditions. Over the centuries, contemplative practice has mostly taken place against
the background of religious belief systems like Buddhism or Hinduism, with meditators trying
to achieve a soteriological goal like “liberation” or “enlightenment.” Accordingly, the phenomenological
taxonomies of such states have been shaped by metaphysical belief systems and an
ancient, traditional cultural context. However, during the last 50 years, a historically new situation
has emerged: Millions of practitioners in Western societies meditate regularly, on a daily
basis, but many of them do so in a secular context and describe themselves a “spiritual but not
religious” (SBNR).
Scientific research in the past century has occasionally taken an interest in states of “pure
awareness,” but mostly from a descriptive angle and using qualitative methods ([1, 2]; for a
review see [3]). Quantitative, including psychometric, approaches have been lacking, particularly
with regard to the phenomenology of such experiences [3–6].
What has emerged from the little research conducted so far has been in line with the traditional
literature, showing states of pure awareness to be characterized by an “absence of
space and time, or body sense” and by the experience of “peacefulness” and “unboundedness”
[2]. Some authors have studied particular aspects of pure consciousness experiences,
such as non-dual awareness. For example, Hanley et al. [7] found two dimensions of the
experience of non-dual awareness: self-transcendence (a dissolving of the boundaries of
the self and a feeling “oneness” with everything around) and bliss (feelings of peacefulness,
love and blissful warmth). Most topical research, however, is more tangential to the phenomenon
of pure awareness, which appears as part of a construct (e.g. in the “mystical”
factor of the Mystical Experience Questionnaire MEQ30 [8]), but is not itself the focus of
investigation.
Here, we study pure awareness specifically, using a psychometric approach and a philosophical
background theory. We present data from the Minimal Phenomenal Experience
(MPE) project, an interdisciplinary initiative aiming at a minimal model explanation of conscious
experience, taking the phenomenal character of “pure consciousness” or “pure awareness”
in meditation as its empirical entry point (for an introduction, cf. [9], sections 1 and 2).
The MPE project has two metatheoretical goals that correspond to two fundamental motivating
questions: What, if anything, can count as the simplest form of conscious experience?
And is it possible to arrive at a minimal model explanation for conscious experience in neurotypical
human beings?
Typical examples of questions related to the first goal are: Phenomenologically, can a conscious
system be exclusively aware of awareness itself? Please note how the concept of “awareness”
we use is a phenomenological one, and not a metaphysical one (which might involve
treating awareness as a Kantian “thing in itself,” or even some mysteriously self-conscious
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ZIP-file on the Open Science Framework website.
URL: https://osf.io/gb76x/download.
Funding: This work was funded by a 5-year
Fellowship awarded to TM by the Gutenberg
Research College, Johannes Gutenberg-Universita t
Mainz (https://www.grc.uni-mainz.de/). The funder
had no role in study design, data collection and
analysis, decision to publish, or preparation of the
manuscript.
Competing interests: The authors have declared
that no competing interests exist.
homunculus looking at awareness itself, etc.). This evidence-based phenomenological
approach implies the possibility of non-egoic self-awareness, i.e., an experience of awareness
itself that is not even subjective in the sense of being tied to a consciously experienced first-person
perspective or a personal-level self-model anymore (see the discussion of Factor 3 and 8
below). If so, would there be a specific form of phenomenal character, a specific experiential
quality that is instantiated during such episodes of pure awareness? Is there something like the
simplest form of conscious experience, and if so, what exactly are the conceptual criteria for
phenomenological “minimality”? Neuroscientifically, what are the minimally sufficient correlates
for MPE to occur in neurotypical humans?
The second goal is to explore a new explanatory strategy. For empirical consciousness
research, the idea is to develop a heuristic strategy of minimalist idealization, by describing
the target phenomenon in an uncluttered way, abstracting away from everything that is not
an essential feature of the core explanandum [9]. For the target of phenomenal consciousness,
does consciousness per se have a distinct experiential character? Does it ever occur in
isolation, and can it be described in a conceptually precise manner? Part of the idea is to look
for the decisive explanatory and computational factors by first attempting to construct
exactly solvable minimal models ([10], p. 37). Such minimal models do not aim at maximal
fidelity or completeness; they are not yet mappings to fine-grained functional mechanisms,
and in this sense, they are idealizations. However, they can be crucial in generating a “minimal
model explanation” [10, 11]. Minimalist idealization proceeds by means of: researchers
constructing and further investigating a parsimonious model of conscious experience that
goes beyond mere correlation but includes only the core causal factors giving rise to the target
phenomenon; including only those causal factors that make a difference to the actual occurrence
and the essential phenomenal character itself; developing an idealized model of universal
and repeatable features serving to gradually isolate the fundamental, explanatorily
relevant, and structurally stable properties that underlie all different forms of conscious
experience. Here, constructing such a minimal model would amount to eliminating superfluous
details by extracting only the explanatorily relevant causal structure underlying the
experience of awareness per se.
The project’s basic working hypothesis is that there exists a form of “minimal phenomenal
experience” (MPE hereafter; [9, 12]) that lacks time representation, spatial self-location,
agency, autobiographical self-awareness, and a phenomenally experienced first-person perspective.
This can be understood as an unstructured form of global content that is also devoid
of perceptual, motor, affective, conceptual and propositional content.
Therefore, the project’s overarching epistemic goal is to find out whether anything like
“pure consciousness” really exists: Is there a state in which only consciousness per se is phenomenally
experienced? However, as an empirical investigation, the current study does not
prejudge the question of the absence of specific contents. Rather, it allows for the possibility
that the non-conceptual experience of consciousness as such can co-occur with conscious
contents. This corresponds to a theoretical treatment of MPE as a phenomenological prototype
without sharp definitional boundaries. We also limit ourselves to one plausibly homogeneous
subclass of MPE states, a paradigmatic form of “pure consciousness” experience as it
appears in the context of systematic and formal contemplative practice. From the relevant
body of Eastern and Western literature and based on a series of pilot studies involving committed
practitioners, we extracted 92 characteristics of the phenomenology of pure consciousness
experiences, which were then formed into questionnaire items. The aim of our
study is to use the questionnaire data to find clusters within these items that could serve
as coherent and meaningful phenomenological dimensions of the experience of pure
awareness.
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Materials and methods
Data collection
Data were collected from Jan 04, 2020 to April 01, 2020 using an online survey hosted on SurveyGizmo
(recently renamed to Alchemer). In phase I, a personal invitation translated into the
five survey languages and containing a link to the survey was emailed by TM to a number of
regular and committed practitioners of meditation. Recipients were asked to further distribute
the survey link. In phase II, the call for participation was extended, via social media, to relevant
organizations and groups all over the world. According to the guidelines of the local ethics
committee of the Department of Psychology of Johannes Gutenberg-Universita t no formal
ethics approval was necessary, because the current study satisfies all criteria for safety and
clearance.
Participants
A total of 3627 survey responses were submitted. Theoretically, the requirement for a respondent
to be included in the factor analysis was to have had at least one experience of "pure
awareness" (N = 2257) and to have submitted complete answers to the 92 items (N = 1171).
In practice, both restrictions were slightly relaxed: 17 participants who failed to answer the
screening question about pure awareness but nevertheless had complete questionnaire data
were kept in the dataset. Respondents with answers to at least 86 items were also retained, as
this increased the analysis sample by over 200 cases compared to those with all 92 items completed.
Further lowering the minimum required number of items, however, resulted in sharply
diminishing returns in terms of sample size. The total number of respondents satisfying the
resulting requirements was N = 1403 (38.7%).
Questionnaire
The questionnaire started with a screening question asking respondents whether they had
ever had an experience of “pure awareness.” Those answering yes were presented with the
full questionnaire including some demographic and personal questions as well as the 92
questionnaire items (“MPE items”). They were instructed to select, and then focus on, only
one single, particular experience of pure awareness that they had had and to answer all MPE
items with regard to that particular experience. If several experiences were eligible, participants
were asked to select "one in which the quality of pure awareness was particularly salient
and/or one which you can remember particularly clearly". To avoid time-based response
effects, presentation order of the items was randomized. At the end of the survey, participants
were also asked to supply a phenomenological report about any of their experiences of
pure awareness.
Respondents who had never had the requisite experience or who stated they did not
understand what we meant by "pure awareness" were asked to complete only the demographic
part of the survey. The demographic questions included biological sex, age, native
language, nationality, country of residence, frequency and duration of meditation practice,
meditation techniques, religious denomination, substance use and presence/absence of a
psychiatric diagnosis.
The core of the questionnaire consisted of the 92 MPE items addressing facets of the experience
of pure awareness that had previously been identified (by TM) in a comprehensive review
of the literature and with the help of advanced practitioners who mostly belonged to the Vipassana
and Zen traditions (similar to the final study sample, see Table 1). For example, there
were items on wakefulness, mood, state of relaxation, presence of thoughts, emotions or
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Table 1. Demographic and other participant information.
Analysis sample % missing
N 1403 0
Median (IQR, min–max) %
Age 52 (22, 17–88) .6
N (%) %
Sex 1.4
male 681 (48.5)
female 702 (50.0)
Chosen questionnaire language 0
German 889 (63.4)
English 440 (31.4)
Spanish 30 (2.1)
Italian 26 (1.9)
French 18 (1.3)
Native languagea 1.4
German 860 (61.3)
English 215 (15.3)
Dutch 55 (3.9)
Spanish 38 (2.7)
Italian 36 (2.6)
French 22 (1.6)
Russian 13 (.9)
Swedish 13 (.9)
Polish 11 (.8)
Hindi 10 (.7)
Portuguese 10 (.7)
Other 100 (7.1)
Country of residence 1.1
Germany 777 (55.4)
USA 110 (7.8)
Switzerland 87 (6.2)
Netherlands 63 (4.5)
United Kingdom 63 (4.5)
Italy 28 (2.0)
Austria 25 (1.8)
Australia 19 (1.4)
France 18 (1.3)
Canada 16 (1.1)
Spain 15 (1.1)
India 13 (0.9)
Sweden 12 (0.9)
Belgium 10 (0.7)
Denmark 10 (0.7)
Nepal 10 (0.7)
Other 112 (8.0)
Nationality 1.2
Germany 786 (56.0)
USA 103 (7.3)
(Continued)
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Table 1. (Continued)
Analysis sample % missing
Switzerland 84 (6.0)
United Kingdom 59 (4.2)
Netherlands 57 (4.1)
Italy 38 (2.7)
Austria 24 (1.7)
Australia 17 (1.2)
India 16 (1.1)
France 15 (1.1)
Sweden 15 (1.1)
Canada 14 (1.0)
Spain 13 (0.9)
Other 145 (10.3)
Meditation experience
Regular meditators 1085 (77.3) 1.3
Median (IQR, min–max)
Years meditating 10 (21, 0–55) 5.2
Sessions per day 1 (1, 0–60) 6.8
Minutes per session 30 (20, 1–240) 9.9
Meditation techniquea 2.7
Vipassana 616 (43.9)
Other 603 (43.0)
Zen 490 (34.9)
Metta 399 (28.4)
Mahamudra/Dzogchen 275 (19.6)
MBSR 274 (19.5)
Shamata 272(19.4)
TM 192 (13.7)
N of meditation techniques practiced 2.7
1 558 (39.8)
2 280 (20.0)
3 253 (18.0)
4 176 (12.5)
5 67 (4.8)
6 17 (1.2)
7 9 (.6)
8 5 (.4)
Substance usea 2.3
None 1161 (82.8)
Cannabis 123 (8.8)
Psychedelics 96 (6.9)
Other 46 (3.3)
Entactogens / MDMA 37 (2.6)
Stimulants 25 (1.8)
Anesthetics or Dissociatives 13 (.9)
Sedatives / Tranquilizers 13 (.9)
Opiates 4 (.3)
GHB / GBL 2 (.1)
(Continued)
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sensory perceptions, presence of a sense of self and the experience of time, to name just a few.
The full list of items can be found in Table 6.
MPE items were answered on a visual analogue scale ranging from 0 to 100, indicating the
degree to which a particular facet of experience was present. In practice, respondents used
their computer mouse to position a slider on a horizontal line (the slider defaulted to the midpoint
of the line). Scale endpoints were given labels appropriate to the form of each question.
Not all items therefore had the same response labels. In questions about the presence and
intensity of a particular phenomenal state (e.g. “Was there a sense of self?” or “Did you have a
visual experience of brightness with closed eyes?”), scale anchors were “No” on the left end
and “Very much so” or “Very strongly” on the right end. In questions about the presence and
frequency of certain countable experiential elements (e.g. “Did you have thoughts?” or “Did
you have memories?”) the label changed to “Very many” on the right end. Occasionally, there
were still other response labels when an item required it (e.g. the question “How alert were
you” had the anchors 0 = “unconscious”, 50 = “normal daytime alertness” and 100 = “much
more alert than normal”).
Although items were presented in a form answerable on a continuous scale, not all items
lent themselves to this approach equally well. For some, dichotomous “yes” / “no” anchors
seemed most appropriate, although even in these cases, a continuous degree of affirmability was
assumed to exist between the binary end points. Example questions include “Did you know that
you would be able to deliberately think thoughts if you wanted to?” and “Would it be a good
description to say that your experience of pure awareness, upon self-recognizing, also recognized
itself as that awareness which had always been present in all experiences in the past?”.
To maximize the number of complete answers, items were “soft-required,” i.e. when
skipped deliberately or accidentally, a pop-up message reminded respondents to provide an
answer if possible. A strict response enforcement was considered counterproductive, as
respondents might legitimately find it hard or even impossible to answer certain questions.
Table 1. (Continued)
Analysis sample % missing
Psychiatric diagnosis 1.1
Yes 90 (6.4)
No 1297 (92.4)
Religious denominationa 1.6
"Spiritual but not religious" (SBNR) / "Spiritual but not affiliated" (SBNA) 639 (45.6)
Buddhist 322 (23.0)
Christian 320 (22.8)
Secular 188 (13.4)
Other 72 (5.1)
Hindu 33 (2.4)
Jewish 7 (.5)
Muslim 4 (.3)
Median (IQR, min–max)
Importance of meditation (0–100) 90 (23, 0–100) 4.1
Importance of religion (0–100) 50 (78, 0–100) 10.1
aMultiple responses were possible. Percentages do not sum to 100%.
IQR = Interquartile Range, max = maximum, MBSR = Mindfulness-Based Stress Reduction, min = minimum,
N = Number, TM = Transcendental Meditation.
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The first 1000 respondents to completely answer all questions were offered a monetary
reward of € 50. The money was transferred using the web service Transferwise. Interested participants
were asked to leave a valid email address, as this was all the service required.
The questionnaire contained one control item (#66), which was a near-duplicate of another
item (#42) about the non-visual experience of "radiance". It was included to provide a sense of
the reliability of item responses.
Translations
Five different language versions of the MPE-92M exist. The original version was developed in
English and subsequently translated into German, French, Italian and Spanish. To create the
translations, a bilingual speaker translated from the English original into a second language,
and then translated back into English. The original and back-translated English versions were
then compared, and adjustments were made if necessary. In some cases, this process required
several iterations.
Statistics
Bartlett’s test for sphericity (p < 0.001) and the Kaiser-Meyer-Olkin Measure of Sampling
Adequacy (.94) confirmed the basic suitability of the data for factor analysis. Due to non-normality
of item distributions, exploratory factor analysis (EFA) was performed on Spearman
correlations using principal-factor estimation. Missing values were deleted pairwise, and the
average number of participants available across all pairwise correlations (N = 1393) was specified
for factor analysis. Loadings were rotated obliquely by the quartimin method in order to
allow for correlated factors. Theoretical and conceptual considerations as well as several statistical
methods were used to guide the number of factors to be extracted. These methods
included the scree plot, the Kaiser criterion (eigenvalue > 1), Horn’s parallel analysis, Velicer’s
MAP criterion and the Bayesian Information Criterion (BIC). Only items with primary loadings
of 0.3 or higher were assigned to their corresponding factors.
To explore the fit of the EFA solution, exploratory factor analysis in the context of confirmatory
factor analysis (E/CFA) was performed. The strongest-loading items per factor were
defined as anchor items whose cross-loadings were fixed at zero, while all other items were
allowed to freely load on all factors. A further identification constraint was to fix factor variances
at unity. E/CFA produces a saturated solution for the loading structure, so that modification
indexes are available only for error covariances. Correlated errors were tentatively allowed
when indicated by modification indexes corresponding to standardized expected parameter
changes of 0.2. Confirmatory factor analysis (CFA) was performed only to assess the fit of
any potential E/CFA solution, on which simple structure was imposed by constraining each
item to load exclusively on its primary factor. Again, factor variances were set to 1 to allow
identification. Internal consistencies per factor were calculated using Cronbach’s alpha.
We refrain from presenting an “optimized” short-form version of the questionnaire.
Although popular, attempts to construct and evaluate a reduced item pool in a dataset resulting
from the larger original item pool are in general methodologically unsound and have been
strongly advised against [13–15].
Fit indexes were interpreted according to recommendations in Brown [16]. Absolute fit
was assessed by the standardized root mean square residual (SRMR) and the root mean square
error of approximation (RMSEA). The SRMR indicates the average discrepancy between
observed and model-predicted item correlations. The RMSEA indicates deviations of the fitting
function from perfect fit and incorporates a penalty for lack of model parsimony. Relative
fit was assessed by the comparative fit index (CFI) and the Tucker-Lewis index (TLI). The CFI
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compares a given model to a baseline model that specifies no correlations between items. The
TLI is similar to the CFI, but again includes a penalty for lack of model parsimony. The following
values were considered to be consistent with good fit: SRMR .08, RMSEA .05, CFI
and TLI .95. To account for non-normality in the data, computations of model fit were
repeated using quasi maximum likelihood (QML) estimation and the Satorra-Bentler correction
[17]. Analyses were performed in Stata 14.2 for Mac [18].
Results
Demographics of analysis sample (N = 1403)
Participants’ mean age was 52 years. The sample was nearly equally split between men and
women (48.5% vs 50.0%). The questionnaire language chosen most frequently was German
(63.4%), followed by English (31.4%). Correspondingly, German was the most frequently
reported native language (61.3%), again followed by English (15.3%). A total of 57 nations
were represented among participants. Regular meditators constituted the majority (77.3%) of
the sample. The most frequently named religious affiliation was “Spiritual but not religious” /
“Spiritual but not affiliated.” Substance use and psychiatric diagnoses were nearly absent.
Complete demographic information is shown in Table 1.
Distribution of meditation techniques
Overall, Vipassana was the most frequently named meditation technique (over 600 reports).
As shown in Fig 1, the single most frequent constellation of techniques was "other" (235 participants),
exclusive Zen meditation (138 participants), and exclusive TM (97 participants).
Comparing respondent groups: Those with vs. those without an experience
of pure awareness
A total of 2466 participants answered the screening question. The vast majority (91.5%,
N = 2257) reported having had at least one experience of pure awareness. In multivariable
regression, speaking German or Spanish as well as every additional ten years of meditation
practice increased the likelihood of a positive response by 2–5%. Being male reduced the likelihood
of a positive response by 4% (Table 2).
Comparing respondent groups: Those with an experience of pure
awareness vs. those not understanding the concept of pure awareness
3.2% (N = 78) of participants reported not understanding the concept of pure awareness. In
multivariable analysis, speaking German and practicing Mahamudra/Dzogchen were the only
statistically significant predictors of understanding and experiencing pure awareness compared
to not understanding it. Again, effects were small, raising the likelihood by 3% (Table 3).
Comparing respondent groups: Those included vs those not included in
factor analysis
Inclusion in the final analysis sample required at least one experience of pure awareness and a
nearly complete set of MPE items (at least 86 out of 92 items). 1403 participants met these
requirements, while 2264 did not. In multivariable analysis, regular meditation, every additional
ten years of meditation practice, speaking German and practicing Shamata, Zen or
some "other", unlisted meditation technique increased the likelihood of being included in factor
analysis by 3–9%. Being male reduced the likelihood by 7% (Table 4).
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Reliability: Control item
In about half of the 1403 participants, scores on the two almost identical items 42 and 66
diverged by 10 or less (Fig 2), with possible differences ranging from 0 to 100.
MPE items: Descriptive analysis
MPE items were generally non-normally distributed. Responses tended to cluster at the
extreme ends of the scale (Fig 3). The highest average ratings were given to items related to
wellbeing and relaxation; the overall lowest rating concerned the presence of pain during the
experience.
Exploratory factor analysis
The number of participants available for factor analysis was 1393. This number is an average
over the number of participants available for each pairwise item correlation, which ranged
Fig 1. Combinations of meditation techniques. Upset plot showing the combinations of meditation techniques occurring in the analysis sample (N = 1403). The
top graph is a histogram, with each bar representing the frequency of a particular (constellation of) meditation technique(s) that is/are identified right below it. Black
dots connected by black lines string together meditation techniques that belong to a given constellation. The bar chart on the left shows the overall frequencies of
each meditation technique.
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from 1357 to 1403. Fig 4 shows factor solutions with 6 to 12 factors obtained by oblique
rotation.
Different statistical criteria for the optimal number of factors yielded different recommendations.
While a scree plot suggested a 4- or 5-factor solution, Velicer’s MAP criterion and the
Kaiser “eigenvalue > 1” rule suggested 9 factors, Horn’s parallel analysis suggested 13 factors
and the Bayesian Information Criterion (BIC) was optimal at 14 factors. The latter, however, is
computed by maximum likelihood estimation under the assumption of multivariate normality,
which does not obtain in our data (see Fig 3).
From a conceptual and theoretical point of view, a solution with fewer than 6 factors was
deemed not sufficiently fine-grained to discriminate between what we considered to be clearly
distinct phenomenological aspects of MPE. A 12-factor solution, based on a loading threshold
of 0.3, was finally chosen as providing an optimal balance between conceptual resolution and
robustness of factors in terms of the number of supporting items.
The factors were named “Time, Effort and Desire,” “Peace, Bliss and Silence,” “Self-Knowledge,
Autonomous Cognizance and Insight,” “Wakeful Presence,” “Pure Awareness in Dream
and Sleep,” “Luminosity,” “Thoughts and Feelings,” “Emptiness and Non-egoic Self-awareness,”
“Sensory Perception in Body and Space,” “Touching World and Self,” “Mental Agency”
and “Witness Consciousness.” Internal consistencies ranged between 0.52 and 0.82, with a
Table 2. Risk ratios comparing participants with (N = 2257) and without (N = 131) an experience of pure awareness.
Unadjusted Risk Ratio [95% C.I.]a Adjusted Risk Ratio [95% C.I.]b % missing
pure awareness (N = 2257) no pure awareness (N = 131)
Age (10-year units) 1.02 [1.01–1.02] 1.00 [0.99–1.01] 16.0 11.5
Male sex 0.94 [0.92–0.96] 0.96 [0.94–0.98] 16.2 12.2
Meditates regularly 1.03 [1.00–1.06] 1.02 [0.99–1.04] 19.6 19.1
Years of practice (10-year units) 1.02 [1.01–1.03] 1.02 [1.01–1.03] 23.0 31.3
Questionnaire language 0 0
English 0.96 [0.93–0.98] N.A.c
French 0.94 [0.83–1.07] 0.96 [0.84–1.11]
German 1.04 [1.02–1.06] 1.04 [1.01–1.07]
Italian 1.00 [0.94–1.07] 1.01 [0.93–1.10]
Spanish 1.03 [0.98–1.07] 1.05 [1.00–1.10]
Meditation technique 21.9 29.0
Mahamudra/Dzogchen 1.01 [0.99–1.04] 1.00 [0.97–1.03]
MBSR 1.03 [1.01–1.05] 1.02 [1.00–1.04]
Metta 1.01 [0.98–1.03] 1.00 [0.97–1.02]
Shamata 1.03 [1.00–1.05] 1.02 [0.99–1.05]
TM 1.03 [1.00–1.05] 1.00 [0.97–1.03]
Vipassana 1.01 [0.99–1.03] 1.01 [0.98–1.03]
Zen 1.01 [0.99–1.03] 1.00 [0.98–1.02]
Other 1.03 [1.01–1.05] 1.02 [1.00–1.04]
aUnivariable general linear regressions with Gaussian distribution, log link and robust standard errors, variable N (1827–2388).
bMultivariable general linear regression with Gaussian distribution, log link and robust standard errors, N = 1750.
cEnglish is the reference category.
p < .05,
p < .01,
p < .001.
N.A. = not applicable.
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mean of 0.72. Nine out of 12 factors had consistencies of 0.70. Table 5 shows factor names,
the proportion of explained variance per factor, and internal consistencies.
Table 6 shows item-to-factor assignments, factor loadings, factor names and item uniqueness
of the 12-factor solution. Uniqueness values, which represent unique, non-shared item
variance, were relatively high, with 32 (35%) of 92 items above 0.6. Correspondingly, total variance
explained by common factors was at a moderate 44%.
Factor correlations, which are a consequence of oblique rotation, are shown in Table 7.
Confirmatory factor analysis
Overall, model fit of the solution from exploratory factor analysis (EFA) was moderate to
acceptable, but significantly degraded after imposing simple structure in a confirmatory factor
analysis (CFA).
A reproduction of the 12-factor solution using EFA in the context of CFA produced a moderate
fit to the data: while absolute fit indexes were consistent with good fit (RMSEA = .034,
90% CI = [.033–.035]; p(RMSEA .05) = 1.0; SRMR = .025), comparative fit was weak (CFI =
.875; TLI = .834). Using the Satorra-Bentler correction slightly improved fit (RMSEA = .030;
Table 3. Risk ratios comparing participants with an experience of pure awareness (N = 2257) to those not understanding the concept of pure awareness (N = 78).
Unadjusted Risk Ratio [95% C.
I.]a
Adjusted Risk Ratio [95% C.
I.]b
% missing
pure awareness
(N = 2257)
did not understand concept
(N = 78)
Age (10-year units) 1.00 [1.00–1.01] 0.99 [0.98–1.00] 15.6 20.5
Male sex 0.99 [0.97-.1.01] 0.99 [0.98–1.01] 16.2 19.3
Meditates regularly 1.02 [1.00–1.05] 1.02 [0.99–1.04] 19.6 21.8
Years of practice (10-year
units)
1.00 [1.00–1.01] 1.01 [1.00–1.01] 23.0 30.8
Questionnaire language 0 0
English 0.98 [0.96–0.99] N.A.c
French 0.99 [0.92–1.07] 0.99 [0.89–1.11]
German 1.03 [1.01–1.04] 1.03 [1.01–1.06]
Italian 1.00 [0.95–1.05] 1.01 [0.93–1.08]
Spanish 0.97 [0.92–1.03] 1.03 [0.98–1.07]
Meditation technique 21.9 35.9
Mahamudra/Dzogchen 1.01 [1.00–1.0] 1.03 [1.00–1.05]
MBSR 1.00 [0.98–1.02] 1.00 [0.98–1.02]
Metta 1.00 [0.99–1.02] 1.01 [0.99–1.03]
Shamata 0.99 [0.97–1.02] 0.99 [0.96–1.01]
TM 1.01 [0.99–1.03] 1.00 [0.98–1.03]
Vipassana 0.99 [0.98–1.01] 0.99 [0.97–1.01]
Zen 1.00 [0.99–1.02] 1.00 [0.99–1.02]
Other 1.01 [1.00–1.03] 1.01 [1.00–1.03]
aUnivariable general linear regressions with Gaussian distribution, log link, and robust standard errors, variable N (1791–2335).
bMultivariable general linear regression with Gaussian distribution, log link, and robust standard errors, N = 1717.
cEnglish is the reference category.
p < .05,
p < .01,
p < .001.
N.A. = not applicable.
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SRMR = .025; CFI = .887; TLI = .849). Model fit improved more noticeably after allowing correlated
errors as indicated by modification indexes corresponding to expected parameter
changes of .2: RMSEA = .025, 90% CI = [.023–.026]; p(RMSEA .05) = 1.0; SRMR = .022;
CFI = .935; TLI = .913. Applying the Satorra-Bentler correction further improved fit very
slightly: RMSEA = .021; SRMR = .022; CFI = .946; TLI = .928.
After imposing simple structure by suppressing cross-loadings, model fit decreased substantially.
While absolute fit was still acceptable (RMSEA = .053, 90% CI = [.052–.054]; p
(RMSEA .05) = 0.00; SRMR = .075), comparative fit was very weak (CFI = .707; TLI = .690).
Comparative fit improved marginally after applying the Satorra-Bentler correction (CFI =
.715; TLI = .699). Allowing correlated errors as indicated by modification indexes corresponding
to expected parameter changes of .2 improved the model, but comparative fit remained
weak (RMSEA = .004, 90% CI = [.039–.041]; p(RMSEA .05) = 1.0; SRMR = .060; CFI = .840;
TLI = .826). Marginal improvement resulted from applying the Satorra-Bentler correction
(RMSEA = .036; SRMR = .060; CFI = .849; TLI = .836).
Phenomenological reports
A total of 1171 reports about experiences of pure awareness were submitted, of which 841
were usable. These will undergo a qualitative analysis, to be published separately.
Table 4. Risk ratios comparing participants included (N = 1403) to those not included (N = 2224) in factor analysis.
Unadjusted Risk Ratio [95% C.I.]a Adjusted Risk Ratio [95% C.I.]b % missing
included in FA (N = 1403) excluded from FA (N = 2224)
Age (10-year units) 1.04 [1.02–1.06] 0.99 [0.96–1.01] 0.6 68.4
Male sex 0.94 [0.88–1.00] 0.93 [0.87–0.99] 1.4 68.2
Meditates regularly 1.13 [1.05–1.22] 1.08 [1.00–1.17] 1.3 72.2
Years of practice (10 year units) 1.04 [1.02–1.06] 1.03 [1.00–1.06] 5.2 74.4
Questionnaire language 0 0
English 0.88 [0.80–0.96] N.A.c
French 0.86 [0.59–1.26] 1.20 [0.98–1.46]
German 1.17 [1.08–1.28] 1.09 [1.02–1.17]
Italian 1.00 [0.74–1.36] 0.88 [0.68–1.15]
Spanish 0.76 [0.56–1.03] 0.90 [0.71–1.14]
Meditation technique 2.7 74.7
Mahamudra/Dzogchen 1.05 [0.98–1.12] 1.03 [0.96–1.11]
MBSR 1.03 [0.96–1.10] 1.02 [0.95–1.10]
Metta 1.03 [0.96–1.09] 1.01 [0.94–1.18]
Shamata 1.09 [1.02–1.27] 1.09 [1.01–1.18]
TM 1.07 [0.99–1.15] 1.06 [0.97–1.15]
Vipassana 1.01 [0.96–1.07] 1.02 [0.96–1.10]
Zen 1.06 [1.00–1.12] 1.08 [1.02–1.14]
Other 1.06 [1.00–1.12] 1.08 [1.02–1.15]
aUnivariable general linear regressions with Gaussian distribution, log link and robust standard errors, variable N (1900–3627).
bMultivariable general linear regression with Gaussian distribution, log link and robust standard errors, N = 1814.
cEnglish is the reference category.
p < .05,
p < .01,
p < .001.
FA = factor analysis, N = number, N.A. = not applicable.
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Discussion
The experience of “pure awareness” has been reported and described in the literature on contemplative
practices since at least around the 8th to 6th century BCE ([19], p39). In this study,
we attempted a first phenomenological characterization of such experiences using a 92-item
online questionnaire distributed among meditators. Over 1400 responses were gathered and
factor-analyzed. The preferred solution contained 12 factors accounting for a moderate 44% of
the total variance, with unique item variances being relatively large. Therefore, the chosen
solution is likely to leave some of the questionnaire’s phenomenological and semantic content
as well as survey response patterns unexplained. In line with this, reproducing the 12-factor
solution in the context of a confirmatory factor analysis resulted in a moderate-to-acceptable
fit to the data, while imposing simple structure produced an ill-fitting solution. It is clear that
the chosen factor solution will not fit the present data well without allowing for a significant
amount of cross-loading.
With these limitations in mind, we now give possible interpretations of the 12 factors in
terms of their phenomenology and our background theory. We also make connections to how
this phenomenology may typically manifest in meditative practice. The interpretations and
connections we propose are predicated on the assumption that these factors or very similar
ones may be reproduced in future studies, which is by no means guaranteed. However, such
speculation may be fruitful for future research by giving rise to new testable hypotheses concerning
the phenomenal structure of pure awareness experiences.
Factor 1 ("Time, Effort and Desire") bundles experiential aspects of a process that could be
described as “dual mindfulness.” Phenomenologically, there is still a meditator and a goal
state, there is a sense of effort created by either mental or bodily agency, and accordingly the
subjective experience of time emerges. Factor 1 points to the conscious experience of a process
that is still goal-directed (there is a desire), and in which there is a sense of effort (for example,
in controlling body posture, or in the subjective experience of repeatedly bringing attention
back to the breath or other objects of meditation, as in Shikantaza, in Shamatha practice or in
Fig 2. Distribution of difference between control items. Distribution of differences in item scores between two
almost identically worded questions (#42 and #66) asking about the presence of a non-visual experience of "radiance".
Item scores range from 0–100, so that the maximum possible difference is 100. N = 1403.
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other forms of focussed-attention meditation). Typically, there will be an attentional lapse, followed
by the phenomenology of noticing, remembering the goal state and re-focussing [20,
21]. As a result, temporal experience is preserved: for example, we find the phenomenology of
duration and of time passing. There may already be an experience of awareness as such, but
this is still a meditation experience, not yet effortless and not a full-absorption episode. (A
“full-absorption episode” is defined as an experience in which MPE is the only kind of phenomenal
character that can later be reported, i.e., a phenomenal state in which the experiential
Fig 3. Distribution of questionnaire items. Statistical distribution of questionnaire items in analysis sample
(N = 1403). Dots indicate medians.
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Fig 4. Results of exploratory factor analysis of the MPE-92M questionnaire (N = 1393). Questionnaire items are
listed on the y-axis. Each column corresponds to a full factor solution with the number of extracted factors given on
the x-axis. The size (area) of the circles is proportional to the factor loadings. Open circles indicate negative loadings,
and loadings below 0.3 are not shown. Color represents factor membership. An attempt was made to identify the
"same" factors across all factor solutions and color them identically. “Sameness” here is not objectively definable, but
the degree of similarity was operationalized as membership in the same cluster following hierarchical cluster analysis.
Items are sorted by factor membership and size of factor loading in the 12-factor solution, as it was this solution that
was finally chosen as optimal.
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quality of “pure consciousness” is the only one that is later available for memory and verbal
report).
Factor correlations show that “Time, Effort and Desire” is negatively correlated with
“Peace, Bliss and Silence” (Factor 2) and “Emptiness and Non-egoic Self-awareness” (Factor
8). This makes good phenomenological sense, because these factors express deep relaxation,
existential ease, a sense of wholeness, positive affect and the atemporal, non-dual and selfless
quality of “pure knowing” (see below). “Time, Effort and Desire” is positively correlated with
the arising of thoughts and feelings, with mind-wandering, discursive thought and different
forms of mental time travel (Factor 7) and also with the noticing of perceptual content arising
(Factor 9). Our data and a qualitative assessment of verbal reports (to be published in a separate
monograph) show how, in a large sample, even experienced meditators and committed
practitioners have varied experiences, including frequent attentional lapses and other banal or
commonplace states. This point also relates to the existence of very short spontaneous occurrences
of MPE in everyday life, and to the micro-meditative technique of “glimpsing” outside
of formal practice, in both of which states of pure consciousness are sandwiched by longer
periods of more ordinary phenomenology. All of this is part of a normal meditation experience,
and to be expected.
What we have defined as “dual mindfulness” (i.e., a process in which there is still a meditator,
a goal state, a sense of effort, and the subjective experience of time) is directly related to a
specific semantic constraint for the concept of MPE which was extracted from the existing literature
in an earlier study, namely “Introspective Availability” (PC4; cf. [9]; section 2.2.1). One
traditional assumption, extensively discussed in Eastern as well as in Western philosophy of
mind, is that we can sometimes actively direct introspective attention to the quality of consciousness
per se. If this turns out to be correct, then one can distinguish different states by the
degree of actually ongoing introspective access to precisely this quality.
Factor 2 ("Peace, Bliss and Silence") picks out the experience of relaxation and ease, which
is perhaps the best-known effect of meditation practice generally. This factor also refers to a
simple experience of deep, unbounded silence (cf. [22]) and “pure being”, which is described
as natural and gentle. The two items relating to the phenomenal experience of “peace” and
Table 5. Factor names and explained variance per factor.
Factor number Factor name % explained variancea Internal consistencyb
1 Time, Effort and Desire 27 0.79
2 Peace, Bliss and Silence 25 0.82
3 Self-Knowledge, Autonomous Cognizance and Insight 16 0.70
4 Wakeful Presence 15 0.67
5 Pure Awareness in Dream and Sleep 15 0.52
6 Luminosity 14 0.76
7 Thoughts and Feelings 13 0.81
8 Emptiness and Non-egoic Self-awareness 13 0.65
9 Sensory Perception in Body and Space 12 0.71
10 Touching World and Self 12 0.72
11 Mental Agency 9 0.74
12 Witness Consciousness 7 0.82
aFactors after oblique rotation are correlated and therefore account for overlapping portions of total item variance. Proportions of explained variance therefore cannot
be summed up across factors. Instead, the total explained variance of the entire factor solution can be obtained as average item communality, which was 44%.
bCronbach’s alpha.
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Table 6. Factor membership and loadings of MPE items in 12-factor solution (with color coding corresponding to Fig 4).
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
25 Did you
experience the
passage of time?
0.76 -0.05 0.00 0.00 -0.02 0.02 -0.01 0.01 0.09 -0.02 0.01 0.03 0.34
24 Did you
experience the
duration of time
as such?
0.73 -0.01 0.00 0.04 0.00 0.01 0.01 0.00 0.04 0.00 -0.06 0.04 0.45
22 Did you
experience time?
0.73 -0.02 -0.01 -0.04 -0.02 0.00 0.00 -0.07 0.08 -0.03 0.01 0.01 0.35
36 Was there a sense
of effort?
0.44 -0.21 -0.14 -0.06 0.10 0.03 0.14 0.08 -0.02 0.02 0.05 0.11 0.43
38 Did you have any
desires?
0.37 -0.14 -0.07 -0.10 0.12 0.01 0.28 -0.01 0.07 0.03 0.03 0.08 0.40
33 Did you have a
sense of bodily
agency, in terms
of actively and
deliberately
controlling your
body
movements?
0.36 -0.11 -0.10 0.08 0.03 0.00 0.09 0.02 0.21 0.02 0.24 0.02 0.52
35 Did you have a
sense of mental
agency, in terms
of actively and
deliberately
thinking
thoughts?
0.28 -0.09 -0.14 -0.03 0.05 -0.04 0.28 0.02 0.05 0.03 0.24 0.07 0.49
17 Was there pain? 0.28 -0.18 0.06 -0.16 0.25 -0.02 0.10 0.10 0.10 0.12 0.05 0.00 0.54
59 Did you
experience the
space of pure
awareness as
having
boundaries?
0.27 -0.20 -0.16 0.00 0.18 -0.07 -0.04 -0.24 0.03 0.14 0.01 0.04 0.49
57 Did your
experience have a
quality that could
be described as a
non-physical
“space”?
-0.23 0.15 0.19 0.00 -0.01 0.19 0.04 0.21 -0.06 0.04 0.07 0.04 0.59
(Continued)
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
60 Did you
experience the
space of pure
awareness as
divisible?
0.22 -0.17 -0.15 -0.08 0.17 -0.02 0.01 -0.11 0.02 0.22 0.00 0.05 0.60
29 Was your
experience part
of your own
inner life?
0.20 0.15 -0.01 0.16 0.15 -0.01 0.10 -0.18 -0.12 0.11 0.15 0.07 0.76
71 Did you feel
relaxed?
-0.05 0.76 0.04 -0.01 -0.01 0.01 -0.01 -0.01 -0.03 -0.07 0.03 0.01 0.37
69 Did you feel at
peace?
-0.03 0.72 -0.04 0.02 -0.09 0.01 -0.02 0.05 -0.03 -0.02 0.02 -0.05 0.38
70 Did you feel at
ease?
-0.01 0.72 0.02 0.03 -0.09 0.04 -0.01 -0.01 -0.02 -0.07 0.02 -0.08 0.37
68 Did you feel
whole?
-0.14 0.54 0.13 0.09 0.00 0.02 0.04 0.02 0.01 0.07 0.02 -0.07 0.44
65 Was there a
subtle but clearly
positive mood,
e.g. like an
"invisible smile"?
-0.06 0.47 -0.05 0.02 -0.15 0.17 0.07 -0.14 0.04 0.21 0.07 0.02 0.53
64 Did your
experience have a
quality of
"blissfulness"?
-0.02 0.45 -0.09 0.11 -0.10 0.23 0.21 -0.02 -0.02 0.18 -0.05 0.00 0.49
67 Did your
experience have a
quality of deep,
unbounded
silence?
-0.02 0.42 0.02 0.02 0.02 0.01 -0.04 0.30 -0.19 0.06 -0.02 0.06 0.52
73 Did you have a
sense that the
state you
experienced was
“the natural
state”?
-0.03 0.40 0.34 0.03 0.03 0.05 -0.03 0.08 -0.03 0.03 0.05 0.02 0.53
63 Did your
experience have a
quality of nontactile
and nonemotional
"gentleness"?
0.04 0.39 0.00 -0.11 -0.02 0.13 -0.17 0.05 -0.04 0.33 0.08 0.06 0.60
(Continued)
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
55 Did you have an
experience of
“pure being”?
-0.06 0.34 0.17 0.26 0.04 0.01 -0.04 0.23 0.01 0.09 -0.03 -0.09 0.46
8 Was your mood
positive?
-0.05 0.32 -0.17 0.28 -0.12 0.18 0.21 -0.06 0.00 0.08 -0.02 -0.12 0.58
86 Is the experience
of pure
awareness the
simplest kind of
conscious
experience you
know?
0.04 0.31 0.23 -0.01 0.03 -0.03 -0.16 0.10 0.06 0.04 0.00 0.04 0.76
89 Did your
experience have a
quality of nonacoustic
"harmony" or
“soundness”?
-0.13 0.29 -0.01 0.08 -0.02 0.09 0.08 0.05 0.00 0.29 0.00 -0.20 0.60
52 Did the
experience have a
quality of
knowing itself?
0.11 0.05 0.46 0.16 -0.01 0.18 0.16 0.02 -0.13 0.05 0.08 0.06 0.56
46 Did your
experience have a
“cognizant”
quality?
-0.10 -0.06 0.42 0.19 -0.07 0.14 0.20 -0.04 -0.11 0.13 0.13 -0.11 0.54
44 Did your
experience have a
quality of
autonomy,
meaning that it
existed all by
itself; that it came
by itself and went
by itself; that it
was nothing you
had created?
-0.19 0.05 0.42 0.01 0.00 0.14 -0.08 0.03 0.07 -0.06 -0.18 0.06 0.59
75 Was there a
quality of
insight?
-0.04 0.03 0.38 0.12 -0.25 0.11 0.23 0.00 -0.03 0.16 0.02 0.06 0.54
(Continued)
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
54 Would it be a
good description
to say that your
experience of
pure awareness,
upon selfrecognizing,
also
recognized itself
as that awareness
which had always
been present in
all experiences in
the past?
0.01 0.07 0.37 0.03 -0.02 0.07 -0.03 0.14 -0.01 0.19 0.07 0.05 0.66
74 Did you have a
sense that the
state you
experienced was
nothing you had
fabricated?
-0.20 0.18 0.37 -0.06 -0.13 0.12 -0.02 0.08 0.07 -0.08 -0.09 0.17 0.54
41 Did your
experience have a
non-visual
quality of
“clarity”?
-0.08 0.11 0.31 0.23 -0.06 0.26 -0.08 0.06 -0.01 -0.06 0.06 -0.08 0.49
45 Was there an
experience of
“pure knowing”
without any
object?
0.02 0.09 0.29 0.17 0.08 0.23 -0.01 0.25 -0.19 -0.07 0.05 -0.03 0.56
82 Did you feel
identical to the
experience of
pure awareness
itself?
-0.07 0.19 0.26 0.19 -0.03 -0.04 -0.01 0.20 -0.01 0.12 -0.02 -0.11 0.59
77 Were you
looking not at
pure awareness,
but from pure
awareness?
-0.07 0.22 0.25 0.07 -0.08 0.01 -0.10 0.16 0.04 0.10 0.06 0.03 0.64
21 Did you have an
experience of
"now"?
0.05 0.03 0.11 0.57 -0.03 -0.03 -0.04 -0.11 -0.04 0.06 0.04 0.19 0.56
(Continued)
PLOS ONE “Pure awareness” in meditators: A fine-grained phenomenological analysis
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
20 Did you have an
experience of
"here"?
0.13 0.11 0.07 0.55 0.04 -0.15 -0.06 -0.18 0.10 0.10 -0.03 0.19 0.56
23 Did you
experience
yourself as being
in the present
moment?
-0.19 0.14 0.10 0.51 -0.04 -0.02 -0.05 0.04 0.04 -0.04 0.05 -0.05 0.47
2 How alert were
you?
-0.07 -0.08 -0.05 0.49 -0.16 0.20 -0.05 0.23 0.05 -0.08 0.11 -0.05 0.53
32 Did you have the
experience of
simply "being",
e.g. of simply
being here and
now?
-0.11 0.34 0.08 0.43 0.04 -0.08 -0.10 0.07 0.04 -0.05 0.02 -0.02 0.50
1 How awake were
you?
-0.02 -0.11 -0.01 0.43 -0.19 0.26 -0.09 0.22 0.02 -0.07 0.08 -0.07 0.55
15 Was there an
experience of
oneness or unity?
-0.17 0.13 0.08 0.32 -0.04 0.09 0.20 0.21 -0.03 0.14 -0.13 -0.04 0.51
56 Did you feel the
fact of your own
existence as
such?
0.07 0.16 0.24 0.24 0.09 0.00 0.01 -0.16 -0.09 0.14 0.11 0.00 0.72
83 Did your
experience occur
during dreamless
deep sleep?
-0.04 -0.07 0.03 0.01 0.72 0.05 -0.03 0.01 0.03 0.04 -0.04 0.05 0.46
84 Did your
experience occur
during the dream
state?
-0.07 -0.08 -0.02 0.05 0.70 0.08 0.02 -0.02 0.03 0.03 -0.04 0.04 0.48
85 Did your
experience occur
during the
normal awake
state, possibly
together with
thoughts and
sensations?
0.11 0.04 0.17 0.08 -0.31 -0.10 0.03 0.02 0.15 0.08 0.14 -0.09 0.78
(Continued)
PLOS ONE “Pure awareness” in meditators: A fine-grained phenomenological analysis
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
40 Did your
experience have a
non-visual
quality of
“brightness”?
0.02 -0.03 0.02 -0.03 0.04 0.73 -0.02 0.03 0.02 -0.02 0.02 -0.01 0.49
42 Did your
experience have a
non-visual
quality of
“radiance” or
"self-luminosity"?
0.09 0.03 0.13 0.02 0.05 0.69 -0.08 -0.03 0.00 0.07 -0.04 -0.02 0.45
66 Did your
experience have a
non-visual
quality of being
"radiant"?
0.02 0.18 0.07 -0.06 -0.06 0.58 -0.05 -0.04 0.04 0.15 -0.04 0.07 0.47
39 Did you have a
visual experience
of brightness
with closed eyes?
-0.06 0.04 -0.18 -0.05 0.20 0.53 0.26 0.04 -0.02 -0.05 0.00 0.08 0.57
62 Did your
experience have a
quality that could
be described as
“vibrant”, but in
a non-tactile and
non-visual sense?
-0.07 0.02 0.03 0.04 -0.11 0.37 0.00 -0.03 0.16 0.23 0.03 0.16 0.64
3 Did you have
thoughts?
0.17 -0.02 0.11 -0.13 0.02 -0.10 0.48 -0.12 0.18 -0.03 0.07 0.04 0.44
6 Did you have
mental images,
e.g. motor
imagery?
-0.10 0.01 0.03 -0.06 0.22 0.05 0.48 -0.07 0.22 0.01 0.01 0.05 0.56
7 Did you have
emotions?
0.07 0.01 -0.05 0.01 -0.02 0.09 0.44 -0.17 0.21 0.08 -0.09 -0.07 0.59
26 Were there
concepts in your
mind?
0.33 -0.09 0.13 -0.15 -0.01 -0.02 0.37 -0.09 0.09 -0.03 0.08 0.10 0.45
4 Did you have
spontaneously
occurring
memories?
0.13 0.07 0.07 -0.17 0.31 -0.07 0.37 0.09 0.12 0.12 0.07 0.01 0.49
(Continued)
PLOS ONE “Pure awareness” in meditators: A fine-grained phenomenological analysis
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
5 Were you
planning or
thinking about
the future?
0.23 0.02 0.07 -0.17 0.31 -0.06 0.35 0.05 0.08 0.06 0.04 -0.05 0.48
27 Was there
discursive
thought?
0.28 -0.05 -0.08 -0.23 0.08 -0.05 0.32 -0.01 0.04 -0.04 0.16 0.11 0.41
43 Did your
experience vary
in its intensity?
0.15 -0.01 -0.21 -0.12 0.03 0.01 0.25 0.06 0.08 0.02 0.13 0.12 0.68
13 Could your
experience be
described as
emptiness, a
vacuum, or a
void?
0.06 0.12 -0.10 0.03 0.11 0.00 -0.07 0.45 -0.21 0.09 -0.05 0.16 0.63
53 Would it be a
good description
to say that there
was “an
emptiness that
has awoken to
itself”?
0.13 0.11 0.14 0.04 0.03 -0.03 -0.09 0.39 -0.15 0.22 -0.01 0.12 0.62
51 Did you feel as
though it was not
you who had an
experience of
“pure knowing”
without any
object, it was
rather as if the
“pure knowing”
was self-aware,
knowing only
itself, while you
had nothing to
do with it?
0.00 -0.04 0.25 -0.05 -0.05 0.12 -0.13 0.38 0.04 0.07 -0.11 0.18 0.59
28 Was there a sense
of self?
0.24 0.08 -0.06 0.14 0.20 -0.04 0.24 -0.37 -0.06 0.00 0.14 0.01 0.49
(Continued)
PLOS ONE “Pure awareness” in meditators: A fine-grained phenomenological analysis
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
91 Did you
experience a
dissolving of the
boundary
between yourself
and your
surroundings?
For example, you
no longer knew
where our body
started and
ended, or you felt
like you were
either everything
or nothing?
-0.25 0.08 0.03 0.01 -0.12 0.01 0.16 0.36 0.00 0.14 -0.17 0.14 0.57
92 Did you have an
experience of
your breath
stopping? E.g., in
the sense that
you felt you no
longer had to
breathe?
-0.12 -0.03 -0.11 -0.04 0.18 0.07 0.04 0.28 -0.12 0.15 -0.02 0.19 0.74
72 Did you
experience the
state of pure
awareness as
neither mental
nor bodily?
-0.17 0.17 0.21 -0.15 0.05 0.07 -0.04 0.24 -0.06 0.07 -0.09 0.04 0.65
81 Is it possible for
you to put your
experience of
pure awareness
into words?
0.00 0.06 0.09 0.13 0.09 -0.02 0.03 -0.14 0.00 0.01 0.08 0.04 0.93
9 Did you have
perceptions, for
example of
objects in your
environment?
0.10 0.01 0.07 0.08 -0.06 -0.07 -0.12 0.02 0.60 0.01 0.06 0.04 0.61
19 Was there
motion in space?
0.12 -0.07 -0.01 0.08 0.10 0.10 0.03 0.08 0.53 0.04 -0.02 0.04 0.59
18 Did you have
movement
sensations?
0.12 -0.03 -0.06 0.01 0.13 0.00 0.10 -0.01 0.52 0.06 0.02 0.07 0.51
(Continued)
PLOS ONE “Pure awareness” in meditators: A fine-grained phenomenological analysis
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
16 Were there
sensory qualities,
e.g. brightness,
colour, sound,
taste, smell?
-0.12 -0.01 -0.04 0.05 0.00 0.25 0.12 -0.10 0.51 -0.05 0.04 0.03 0.62
12 Did you feel your
body if you did
not deliberately
attend to it?
0.25 0.03 -0.01 0.10 0.01 -0.11 -0.07 -0.15 0.37 0.09 0.10 -0.02 0.63
11 Did you have
temperature
sensations?
0.14 0.07 -0.08 -0.09 0.16 -0.02 0.14 0.07 0.35 0.12 0.03 0.02 0.63
14 Was awareness
itself the only
content of
awareness?
-0.11 0.06 0.00 0.19 0.15 -0.03 -0.21 0.18 -0.30 0.04 -0.04 -0.05 0.62
10 Did you have
weight
sensations?
0.13 0.00 -0.12 -0.08 0.17 -0.08 0.15 0.08 0.28 0.10 0.04 0.11 0.62
79 Did your
experience of
pure awareness
have an abstract
quality of “selftouch”,
but not
in a tactile sense?
-0.04 -0.07 0.06 0.00 0.11 0.04 -0.02 -0.05 -0.05 0.63 0.04 0.00 0.58
80 Was your
experience of
pure awareness
like the entire
body touching,
and
simultaneously
being touched
by, the world?
-0.05 -0.04 -0.02 0.06 0.00 -0.02 0.07 0.16 0.12 0.60 -0.04 -0.07 0.58
(Continued)
PLOS ONE “Pure awareness” in meditators: A fine-grained phenomenological analysis
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
78 Did your
experience of
pure awareness
resemble the
concrete tactile
experience you
have when you
touch your left
hand with your
right hand,
creating the
experience of
touching and
being touched at
the same location
simultaneously?
0.06 -0.13 0.04 -0.09 0.02 0.01 -0.09 -0.02 0.05 0.54 0.02 0.10 0.66
61 Did your
experience have a
quality that could
be described as
“velvety”, but in a
non-tactile sense?
0.06 0.20 -0.15 -0.11 0.09 0.17 -0.11 0.05 0.02 0.42 0.10 0.02 0.66
88 Did your
experience have a
quality of nontactile
"density"
or "fullness"?
-0.16 0.03 0.04 0.04 0.01 0.14 -0.03 -0.05 0.02 0.42 0.01 0.07 0.70
87 Did you have an
experience of
pure awareness
penetrating your
body, e.g. like a
field that also
penetrates all
other objects and
living things?
-0.10 0.05 0.06 0.04 -0.05 0.12 0.08 0.26 0.07 0.37 0.04 -0.03 0.63
58 Did you
experience the
space of pure
awareness as
having a centre?
0.17 -0.06 -0.09 0.06 0.14 0.01 0.05 -0.19 -0.06 0.28 0.06 0.01 0.74
90 Did you have a
sense of awe or
wonder?
-0.09 0.00 0.09 0.13 -0.26 0.08 0.23 -0.08 0.02 0.27 -0.08 0.14 0.70
(Continued)
PLOS ONE “Pure awareness” in meditators: A fine-grained phenomenological analysis
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
50 Did you have a
sense of
confidence that
you would be
able to know
things in the
future?
0.05 -0.09 0.12 0.02 0.15 0.14 0.19 -0.04 -0.03 0.24 0.16 -0.01 0.73
76 Was your
experience of
pure awareness
different from an
experience of
pure awareness
that “has become
aware of itself”?
-0.03 -0.07 -0.10 0.01 0.05 0.02 0.04 0.01 -0.03 0.12 -0.02 -0.03 0.97
47 Did you know
that you would
be able to
deliberately
control your
attention if you
wanted to?
-0.10 0.04 0.00 -0.04 -0.03 0.01 -0.05 0.01 0.02 -0.01 0.81 0.03 0.38
48 Did you know
that you would
be able to
deliberately think
thoughts if you
wanted to?
-0.02 0.02 0.05 -0.01 -0.01 -0.02 -0.05 0.04 0.04 -0.01 0.78 -0.01 0.41
49 Did you have a
sense of
confidence that
you would still be
alert in the next
moment?
-0.06 0.05 0.13 0.10 -0.06 0.07 -0.03 -0.11 -0.08 0.05 0.47 -0.02 0.68
37 Were you aware
of meditating?
0.07 -0.01 -0.15 0.15 0.00 -0.05 0.13 -0.07 -0.14 0.04 0.41 0.06 0.70
34 Did you have a
sense of mental
agency, in terms
of actively and
deliberately
controlling the
focus of your
attention?
0.17 -0.03 -0.24 0.08 0.00 -0.05 0.23 0.01 0.04 0.02 0.39 0.11 0.52
(Continued)
PLOS ONE “Pure awareness” in meditators: A fine-grained phenomenological analysis
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Table 6. (Continued)
Factor
1
Factor
2
Factor 3 Factor 4 Factor 5 Factor 6 Factor 7 Factor 8 Factor 9 Factor 10 Factor
11
Factor 12 Uniqueness
Item
Nr
Item long name Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body and
Space
Touching
World and
Self
Mental
Agency
Witness
Consciousness
31 Did you have the
experience of a
passive observer
being present?
-0.02 0.00 -0.01 0.05 0.02 -0.01 0.00 -0.01 0.00 -0.05 0.03 0.78 0.41
30 Did you have the
experience of an
impersonal
observer being
present?
-0.01 -0.05 0.02 0.04 -0.02 0.03 -0.02 0.05 0.02 0.00 0.01 0.75 0.43
https://doi.org/10.1371/journal.pone.0253694.t006
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“wholeness” show an absence of mental conflict and an increased degree of integration. This is
to be expected in all states in which a) the constant competition of different mental processes
for the focus of attention (for example, the automatic arising of spontaneous, task-unrelated
thought; [23–26]) has subsided, and b) representational contraction into a first-person perspective
[27] and the resulting fragmentation of one’s overall experiential space by goaldirected
mental agency have been attenuated.
A low degree of perturbation also confirms the second of six semantic constraints for the
working concept of “MPE” which were extracted in the above-mentioned study, this one
termed “Low Complexity” (PC2; cf. [9]). Generally speaking, PC2 is often described as the
complete absence of intentional content, in particular of high-level symbolic mental content
(i.e., discursive, conceptual or propositional thought), but sometimes even as the disappearance
of all sensorimotor, interoceptive and affective content. There is a weak and a strong
reading of this semantic constraint, distinguishing between the mere phenomenological
absence of cognitive agency, mind-wandering or mind blanking on the one hand (for details,
Table 7. Factor correlationsa.
Time,
Effort
and
Desire
Peace,
Bliss
and
Silence
Self-
Knowledge,
Autonomous
Cognizance
and Insight
Wakeful
Presence
Pure
Awareness
in Dream
and Sleep
Luminosity Thoughts
and
Feelings
Emptiness
and Nonegoic
Selfawareness
Sensory
Perception
in Body
and Space
Touching
World
and Self
Mental
Agency
Witness
Consciousness
Time, Effort
and Desire
1.00
Peace, Bliss
and Silence
-0.40 1.00
Self-
Knowledge,
Autonomous
Cognizance
and Insight
-0.26 0.32 1.00
Wakeful
Presence
-0.22 0.34 0.28 1.00
Pure
Awareness in
Dream and
Sleep
0.35 -0.29 -0.20 -0.29 1.00
Luminosity -0.24 0.30 0.24 0.19 -0.08 1.00
Thoughts and
Feelings
0.31 -0.06 -0.10 -0.12 0.23 0.10 1.00
Emptiness and
Non-egoic
Self-awareness
-0.30 0.21 0.22 0.07 -0.07 0.23 -0.19 1.00
Sensory
Perception in
Body and
Space
0.37 -0.19 -0.08 -0.08 0.11 0.01 0.28 -0.19 1.00
Touching
World and Self
0.06 0.24 0.15 0.12 0.15 0.31 0.18 0.13 0.09 1.00
Mental Agency 0.28 0.05 -0.03 0.11 0.00 0.01 0.20 -0.15 0.12 0.10 1.00
Witness
Consciousness
0.25 -0.13 0.03 -0.02 0.22 0.07 0.09 0.07 0.15 0.19 0.10 1.00
aCorrelations |0.3| are printed in boldface.
https://doi.org/10.1371/journal.pone.0253694.t007
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see [9]) and a “full-absorption episode” (as defined above) on the other. Both readings are
compatible with Factor 2.
Recent research on mind-wandering has shown that “a wandering mind is an unhappy
mind” [28]. Three items in Factor 2 pick out positive mood and the phenomenal quality of
“bliss” as often co-emerging with the silent mind of the meditator. A preliminary qualitative
analysis of 841 phenomenological reports indicates that MPE as such is not an emotional state,
but that it can certainly trigger a whole spectrum of mostly positive affective states like joy,
existential relief, gratitude, unpersonal love, awe and wonder (but see [29]). In particular, MPE
can sometimes co-exist with a mostly subtle but clearly noticeable form of bliss, an experience
that has sometimes been described as an “invisible smile” (Item 65). Factor 2 therefore
expresses not only the phenomenology of peace, existential ease and silence, but also various
forms of what in German is called Stilles Entzücken (“silent delight”), which seems intimately
connected to a calm and entirely undramatic phenomenology of rapture and “non-sensational
awe.”
Factor 3 was termed “Self-Knowledge, Autonomous Cognizance and Insight”. It matches
one of the two most central semantic constraints for the concept of “MPE”, namely “Epistemicity”
(PC5 in [9]), the non-conceptual phenomenal experience of “knowingness.” This means
that MPE instantiates an autonomous (i.e., unfabricated) phenomenal character of insight,
cognizance and clarity.
The strongest-loading item in Factor 3 (“Did the experience have a quality of knowing
itself?”) expresses a phenomenology of non-egoic, first-order reflexivity: The non-conceptual
quality of “pure knowing” is self-directed, but in a non-egoic way, without the involvement of
any kind of mental or bodily agency, without a conscious sense of control or ownership, and
excluding the phenomenology of “selfhood” in terms of transtemporal identity. Accordingly,
“pure knowing” also lacks the phenomenal experience of personhood, a conscious representation
of being a rational individual possessing specific personality traits or any form of autobiographical
narrative. Phenomenologically, pure awareness simply knows itself, timelessly.
The interesting discovery is exactly that there is now empirical evidence for a non-egoic,
homunculus-free form of self-awareness. Therefore, we also find a strong phenomenological
relationship to Factor 8 ("Emptiness and Non-egoic Self-awareness"). Our own approach is
one of evidence-based phenomenology, but in ancient contemplative traditions this type of
state has for many centuries been described epistemically, as “self-knowing timeless awareness”
or as “self-cognizing wakefulness” (for example, in the Tibetan notion of rang rig ye
shes).
Factor 4 ("Wakeful Presence") integrates the phenomenology of spatiotemporal self-location
(cf. [30]) with alertness and the unified experience of “existence as such.” There is a phenomenal
experience of being fully settled in the “Here” and the “Now,” permeated by the
character of wakefulness and a feeling of “simply being.” We labelled this cluster of phenomenal
qualities “Wakeful Presence” because its four strongest-loading items refer to the embodied
experience of wakefully being in the present moment. The alertness component directly relates
to and confirms the first, and most prominent, semantic constraint for the concept of “MPE,”
as derived from a previous study, namely “Wakefulness” (PC1 in [9]). If one interprets wakefulness
as a functionally autonomous conscious representation of epistemic capacity (for
example, of the existing capacity for self-orientation in time and space, plus the capacity for
attentional control), then one finds a direct link to Factor 3 ("Self-Knowledge, Autonomous
Cognizance and Insight"). In Tibetan Buddhism, the relevant phenomenology was described
more than a thousand years ago as “self-generating ever-fresh awareness” ([31], xi) and as the
experiential quality of originary, naturally present and non-transient “primordial knowing”
(ye shes in Tibetan; cf. [32], p447, [33], p99).
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Factor 4 also incorporates two additional elements, however, namely items pointing to the
phenomenal qualities of unity and of onticity (pure being, or being as such). The latter has also
been reported in the context of syncopes and accidents (for discussion, see [9], note 21). Both
reappear in our qualitative assessment under the rubric of “non-dual being.”
Factor 5 (“Pure Awareness in Dream and Sleep”) is a special case and will, if replicated, be
treated more thoroughly in future publications. It relates to the experience of pure awareness
during NREM (non-rapid eye movement) sleep, which is a type of full absorption [34, 35]. As
the second “stand-alone instance” of our research target, it will be of great relevance in triangulating
the neural correlates of MPE. A number of first-person reports from our study support
the existence of such states.
Pure awareness during NREM-sleep has previously been termed “lucid dreamless sleep” or
(by the TM movement) “witnessing sleep.” Factor 5 shows interesting relations not only to the
phenomenologies of “wakeful presence” and “non-dual being” already mentioned, but also to
Factor 12 (“Witness Consciousness”) and Factor 6 (“Luminosity”).
Factor 6 (“Luminosity”) refers to non-visual phenomenal qualities of “brightness,” “radiance”
and “vibrancy,” but also to the visual experience of brightness with closed eyes. In addition,
“Self-Luminosity” (PC3) was one of the six semantic constraints previously extracted,
where it may also be found as the phenomenology of “brilliance” or as the “clear light of primordial
awareness.”
The specific kind of phenomenal character sometimes described as “luminosity,” “radiance”
or even “enlightenment” comes in different varieties. For example, many practitioners
describe a non-visual phenomenology of “clear light,” a non-perceptual experience of clarity
and mere epistemic openness, while others report a more concrete form of visual brightness,
which can be experienced with closed as well as with open eyes.
According to classical Buddhist teachings, the term “luminosity” simply refers to an entirely
non-conceptual experience of epistemic capacity, the capacity to know and experience (Tib.
salwa; e.g., [36], p36; n. 30), and would therefore be directly related to Factor 3 (“Self-Knowledge,
Autonomous Cognizance and Insight”). Here, we could also speak of the phenomenal
experience of epistemic clarity. This involves an open, currently unobstructed inner space of
knowing, a space in which orientation and perceptual processes can unfold, in which attention
can be controlled and focused or in which concepts can be formed and applied to experience.
MPE would be a model of this space.
Factor 7 (“Thoughts and Feelings”) describes a classical meditation experience, just like the
phenomenal descriptors picked out by “Time, Effort and Desire” (Factor 1). Thoughts of different
kinds, mental images, emotions, memories and simulations of future events spontaneously
arise. There is time experience, and the space of silent, spacious awareness into which
the meditator wants to settle is more or less clouded. Phenomenologically, there is a mostly
noisy foreground of active mental content.
Factor 8 (“Emptiness and Non-egoic Self-awareness”) may be most interesting from a
philosophical perspective. In our study, it refers to an experiential quality of “pure knowing”
without a sense of self and without any object. The relevant items describe an uncontracted,
unbounded, and non-dual experience of wakefulness without content, which is self-aware,
knowing only itself in a way that lacks any markers of egoic self-consciousness like agency,
ownership, and autobiographical narrative, or spatiotemporal self-location [27, 30]. However,
our formulation of the strongest-loading item in “Emptiness and Non-egoic Self-awareness”
may mistakenly conflate “emptiness” with the merely spatial phenomenology of consciously
experiencing a void or a vacuum.
“Emptiness” (su atā in Pali) is one of the foremost concepts in Buddhist philosophy. It
has been discussed by scholars and practitioners for far more than two thousand years. From a
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metaphysical perspective, “emptiness” means that all phenomena lack substantiality and an
intrinsic nature of their own. From a phenomenological perspective, full-absorption states in
which pure awareness remains as the only reportable phenomenal character are a prime candidate
for an “experience” of emptiness, the stand-alone quality of epistemic openness as discussed
in the context of Factor 6 above. Phenomenologically, “seeing the empty nature of
phenomena” can also refer to a conscious experience without the slightest trace of conceptual
overlay, namely to the distinct and crystal-clear phenomenology of seeing and perceiving out
of timeless silence.
Interestingly, the second- and third-strongest loading items in Factor 8 were those offering
two metaphorical descriptions of first-order reflexivity combining the “Self-Knowledge,
Autonomous Cognizance and Insight” of Factor 3 and the “Wakefulness” of Factor 4 with the
phenomenal quality of emptiness and epistemic openness. These are negatively correlated with
the phenomenology of selfhood: The phenomenology of self-knowing and self-awakening
picked out by this factor is non-egoic. Arguably, it is exactly these aspects of Factor 8 that, for
many participants, may express the “spiritual essence” of MPE most directly. Evidence for the
actual existence of non-egoic self-awareness in the context of a substantial psychometric study
is a theoretically relevant result.
Factor 9 (“Sensory Perception in Body and Space”) describes the presence of sensory qualities,
movement sensations and conscious body experience, implying that the phenomenal
character of MPE can co-emerge with perceptual content. Qualitative analysis of reports
shows it as related to the frequently described phenomenology of “direct perception.” For
many centuries, meditators have reported states of direct perception, the experience of seeing
what is. Seeing what is out of a state of pure awareness often reveals another particular and
interesting, phenomenal quality, namely the experience of “suchness” or “thusness”, the ineffable
uniqueness and particularity of any individual instance of non-conceptual content. This
suggests another evidence-based, phenomenologically grounded reading of the “purity” of
pure awareness, not as the absence of perceptual content, but as a complete lack of conceptual
overlay and cognitive penetration, including time experience and judgements as to the “existence”
or “non-existence” of what is perceived.
Factor 10 (“Touching World and Self”) describes MPE as an abstract form of tactile experience
resembling self-touch (for example, the specific sensation of inter-manual self-touch) or
as a tactile experience in which the entire body touching the world while simultaneously being
touched by it. Other phenomenological descriptors are “velvety,” “dense” and “full”—but
always in a non-tactile way, i.e., as lacking the concrete phenomenal qualities normally characterizing
the stimulus-correlated sense of touch. Here, the phenomenological profile of MPE is
described, first, as an abstract form of contact or of “being in touch;” second, it can exhibit the
phenomenal character of reflexivity (as in self-touch; or Factor 8; [37, 38]); and, third, it can
be globalized, namely in the form of “an experience of pure awareness penetrating your body,
e.g. like a field that also penetrates all other objects and living things” (Item 87). One interesting
detail is the correlation of Factor 10 with Factor 6 (“Luminosity”). As there is no obvious
phenomenological relationship between qualities like “brightness,” “brilliance” or “radiance”
and the ones just mentioned, this might perhaps point to interesting commonalities in the
neural substrate.
Factor 11 ("Mental Agency") points to subtle forms of egoic mental self-awareness, like
being aware of the fact that one is currently meditating, experiencing the potential for sustained
alertness and cognitive-attentional self-control, or even—in Item 34—having an explicit
sense of mental agency unaccompanied by any actually ongoing, deliberate control of the
focus of attention. This factor picks out phenomenological configurations in which egoic
awareness, specifically the more subtle phenomenal qualities emerging from representing
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one’s own capacity for mental action, are still superimposed onto MPE. This feature also refers
back to the notion of “dual mindfulness” as introduced when discussing Factor 1 ("Time,
Effort and Desire").
Finally, Factor 12 ("Witness Consciousness") demonstrates how a classical term from the
Advaita Vedanta (i.e., sākṣin; Sanskrit: साक्षी; [39, 40]) system of philosophy finds its expression
on the level of phenomenology. Witness consciousness is that which makes all knowledge
possible, cannot itself become an object of knowledge and is self-luminous (for more, see [9]).
“Witness consciousness” also is a global phenomenology. This is to say that the totality of all
experiential contents is experienced as being observed by something that isn’t really an
“observer” at all, but rather a timeless, absolutely impersonal, knowing presence. Phenomenologically,
the world is mirrored in an all-encompassing quality of infinite, choiceless and nonconceptual
knowing.
It is interesting to note how Factors 3 (“Self-Knowledge, Autonomous Cognizance and
Insight”) and 4 (“Wakeful Presence”) offer phenomenological support for results from the textbased
evidence synthesis presented in [9], in which the two most important semantic constraints
for MPE emerge as and “Epistemicity” (PC3) and “Wakefulness” (PC1), while Factor
6 (Luminosity”) directly maps onto the constraint which was termed “self-luminosity” (PC3)
in this earlier investigation. Meanwhile, a highly intuitive pattern found in the present data is
that the qualities of control, desire, effort and time experience found under Factor 1 are clearly
anti-correlated with “Peace, Bliss, and Silence (Factor 2) and what is arguably the most “spiritual”
factor (Factor 8, “Emptiness and Non-egoic Self-awareness”), while positively correlating
with dream, sleep, and mental activity on the cognitive and perceptual level.
Insofar as it is phenomenologically plausible, the 12-factor solution presented shows that a
dimensional approach is viable and that the concept of “MPE” may be a graded construct
which refers to a multidimensional space of possible conscious states, a space which may contain
different points, regions or trajectories [9, 41]. MPE might then be a cluster concept with
a probabilistic rather than a definitional structure, where membership is graded along multiple
dimensions and some phenomenological exemplars are more prototypical than others. Since
“pure awareness” experiences may be maximally prototypical, we might conjecture that a
majority of respondents in our study will describe such states as the simplest kind of conscious
experience they know. This is borne out by the fact that the corresponding item #86 in our
questionnaire achieved a median rating of 80. However, it is important not to conflate subjective
ratings of “simplicity” with whatever objective measures we may develop in the future.
Accordingly, future research may demonstrate that even less complex forms of phenomenal
character do exist and constitute the simplest form of conscious experience neurotypical
human beings are capable of.
Limitations
Our study has a number of limitations. Most fundamentally, there is no guarantee that participants
understood the instructions and the concept of “pure awareness” introduced therein in
the way we intended them. Varying understandings may have led to unwanted variation in
responses. Even assuming a singular, precise and unequivocal understanding, it is still possible
that some responses were driven largely by a desire to report particularly impressive or personally
meaningful experiences rather than to adhere as closely as possible to the instructions.
There is some evidence for this in the 841 phenomenal reports collected as part of the questionnaire,
where a number of participants chose to report not “ordinary” MPE as it may occur
during formal meditation practice and full-absorption episodes, but rarer and often quite dramatic
non-dual awareness states in which all subject–object structure had spontaneously
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disappeared. This may have been an indirect effect of us asking participants for a description
of an experience “in which the quality of pure awareness was particularly salient and/or one
which you can remember particularly clearly.” What can be remembered particularly clearly
may often be the most impressive states, which may not necessarily be the most paradigmatic
instances of “pure awareness.”
More generally, differences in understanding of any part of the survey (items, demographic
questions) could have led to undesired response variability. Such differences can occur for a
number of reasons. First, participants will typically have been exposed to different background
information about meditation. If they have actively engaged with the relevant literature, there
may have been large differences in what was selected for study. For instance, many of our participants
(77%) were regular practitioners who had been meditating for years. It is plausible to
assume that such a consistent habit may often be anchored in adherence to specific belief systems
and the conceptual framework of a certain lineage or spiritual tradition or a specific
teacher or organization. The terminology employed by such theories, as well their epistemological
and metaphysical background assumptions, may “contaminate” survey responses (and
phenomenological reports). We know from correspondence that such belief systems can
sometimes even lead to a decision not to participate in scientific projects or to reject any
attempt to try to approximate something considered to be as fundamentally ineffable and
soteriologically relevant as MPE. Therefore, “theory contamination” may have both biased
questionnaire responses and introduced a selection bias into the sample.
A second issue is what could be called “response drift”: Some participants may have started
out with a somewhat vague idea of the target state of pure awareness, which became increasingly
focused as they moved through the questionnaire. Conversely, they may have started out
with a very specific concept, perhaps dictated by commitment to a particular theory, and then
similarly shifted as they moved through the questions. Responses given earlier may therefore
have related to a somewhat different target than what later responses referred to. This could
explain the observed divergence in responses to the two control items, which occurred at different
places in the questionnaire, but were nearly identically phrased. In hindsight, it might
have been better to phrase these items not just nearly, but absolutely, identically in order to be
sure that any intra-individual variation in responses must be due to inconsistent reporting. As
it was, divergent scores could also be due to the slight semantic difference in the two items,
one asking about non-visual radiance only, while the other also asked about self-luminosity.
We did not exclude any participants based on the difference in their control item scores. We
are generally very cautious about excluding participants and prefer to err on the side of inclusion
unless there is a compelling rationale for doing otherwise. Also, a non-arbitrary exclusion
criterion is hard to find in this case. But most importantly, a single pair of control items is
much too noisy a criterion to offer a sound basis for data exclusion.
In studies of “private” subjective experiences, there is a general set of problems associated
with verbal report. One issue is ineffability: the difficulty or impossibility of expressing certain
phenomenal states or qualities in words. This problem may be particularly pronounced when
it comes to MPE, since the experiential quality of “pure awareness” has long been regarded by
meditators as the paradigmatic example of ineffability. The ineffability problem may arise for
several reasons. One is a lack of concurrent reportability during full-absorption episodes ([9],
p14). Due to the non-dual nature of such states (i.e., the lack of any phenomenally represented
subject–object structure) there will be no intention or cognitive capacity to verbally report,
mentally categorize or actively memorize the phenomenal character in question. Another reason
may be that MPE’s timeless content is unlike [42, 43] any of the more familiar sensory,
motor and interoceptive qualities, making it hard to grasp it verbally by comparing it to such
qualities. A final source of ineffability is that the experience of MPE typically seems to lack any
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internal structure or “grain,” It seems uniformly dense. This phenomenal quality of “ultrasmoothness”
[44–46], as it is called in the literature, may further hinder verbal report by
depriving it of any discernible entry points for description or functional analysis.
Alongside ineffability issues, another problem faced by all studies based on retrospective
self-report is the unreliability of memory recall. Human autobiographical memory, including
recall of previous mental states, is notoriously fallible (for a review see [47]). In our study, we
asked participants to report on experiences that occurred in their past, possibly even decades
ago. Memory retrieval for such events will be necessarily biased, depending on various factors
such as the amount of time that has since passed. The uncertainty introduced by such errors
may be substantial but is likely to remain unavoidable in studies of this kind.
On a conceptual level there is an even deeper variant of the memory problem: If the concept
of “autobiographical memory” refers to the representation of events which at the time at which
they occurred were phenomenally represented as being experienced by a conscious self, then a
participant’s claims that they themselves have experienced a selfless state are highly dubious
from a methodological perspective, because they contain either a logical or a performative fallacy
([48], p566). A memory of a pure-awareness experience could not be autobiographical
memory in this strong phenomenological sense. Of course, it may be empirically possible that
selfless states are stored and later retrieved in an autobiographical format, as a post hoc mnemonic
misrepresentation adding the feature of egoic self-awareness–a case of misremembering,
and not of confabulation (cf. [49, 50] for important discussions). But the relevant evidence
has yet to be gathered.
One weakness of our anonymized online survey approach is that the identities of participants
could not be verified, nor could we detect fraudulent responses or multiple responses by
the same person. As part of privacy protection, IP addresses were not stored and could therefore
not be used for data plausibility checks.
Finally, our data are highly unlikely to be representative of the global population of meditators.
The online nature of the questionnaire and its distribution channels as well as self-selection
will have produced a sample that deviates in several respects from the global population.
The high number of incomplete responses (over 60%) also indicates a massive self-selection
process, probably driven in part by the large number of questionnaire items, which may have
been off-putting. However, representativeness is not a major concern at this stage. Future versions
of this questionnaire will be put to the test against different populations and will be modified
to provide a factor structure that holds up in as many settings as possible. Methods from
confirmatory factor analysis can then be used to quantify the differences in item functioning
and response patterns among different groups of participants.
Conclusion
A central notion in traditional philosophical theories of meditation is that of “pure consciousness”
or “pure awareness,” the experience of being non-conceptually aware of consciousness
itself. Based on responses to an online questionnaire, we here offer a factor structure to map
the phenomenal character of such experiences in a fine-grained way. The 12 resulting dimensions
not only reproduce important aspects of this phenomenon as reported in the literature,
such as the actual existence of non-egoic self-awareness, they also point to some potentially
new connections such as that between “Luminosity” and the abstract, non-tactile experience of
self-touch.
However, our factor solution accounts for less than half of the item variance and quantitative
measures indicate a lack of fit, particularly when simple structure is imposed. Future studies
will be needed to improve upon this first version of the rating scale and to continue to
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validate it in different populations and settings, including sleep states, non-meditative states
and altered states of consciousness.
The under-researched experience of “pure awareness” in meditation is of great relevance to
the interdisciplinary field of consciousness research. Pure awareness opens up a new methodological
perspective by generating potential for a minimal model explanation, which in turn will
contribute to the construction of a minimal unifying model (cf. [9, 51]). The study of pure
awareness also helps in refining important theoretical questions in consciousness studies, for
instance as regards ineffability and the relevance of dimensional approaches to fine-grained
phenomenological analysis. Finally, it may foster theoretical unification by connecting the
major existing approaches in a new way.
Acknowledgments
We thank Tiziano Furlanetto, Sol ne Neyret, Adriana Alcaraz Sanchez, Jennifer Windt and
Raphae l Milli re for help with questionnaire translation. We are grateful to Tiziano Furlanetto,
Sol ne Neyret, Adriana Alcaraz Sanchez and Wanja Wiese for help with translation and qualitative
assessment of phenomenological reports. In particular, TM wants to thank all those
committed practitioners who supported the project during the pilot and distribution phase,
including Nicole Baden, Tilman Borghardt, Irene Bumbacher, Cyril Costines, Safae Essafi,
Nicole Fasel, Catherine Felder, Matt Gwyther, Sam Harris, Britta Ho lzel, Gu nter Hudasch,
Yuka Nakamura, Muho No lke, Ulrich Ott, Fred von Allmen, Toby Woods and others. We are
greatly indebted to Erich Studerus for comments, and to Emily Troscianko, Wanja Wiese, and
Cyril Costines for editorial help.
Author Contributions
Conceptualization: Alex Gamma, Thomas Metzinger.
Data curation: Alex Gamma.
Formal analysis: Alex Gamma.
Funding acquisition: Thomas Metzinger.
Methodology: Alex Gamma, Thomas Metzinger.
Resources: Thomas Metzinger.
Supervision: Thomas Metzinger.
Visualization: Alex Gamma.
Writing – original draft: Alex Gamma, Thomas Metzinger.
Writing – review & editing: Alex Gamma, Thomas Metzinger.
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