PONE-D-23-11057Differential Relationship Between Meditation Methods and Psychotic-Like and Mystical ExperiencesPLOS ONE

Dear Dr. Palmer,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please address all the comments and questions raised by the reviewers. As per the request of one of the referees, please have a statistician review the analyses to ensure the robustness of the statistical methods 

Please submit your revised manuscript by Sep 03 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Rakesh Karmacharya, MD, PhD

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: I Don't Know

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This is a very interesting but under-researched area of study, and these results have potential clinical implications, so it is welcome that the researchers have decided to conduct this study. Below I describe my main concerns and suggestions.

Causal inference

In the section “Subjective Causality of Meditation Method Use and PLEs” you talk about a criterion for causality citing WHO 2013, “an event that happens concurrently or right after an intervention.” This addresses one of many causal attribution criteria for assessing adverse effects of pharmacological interventions, but it is not really sufficient on its own – please reflect this in your wording. The Varieties of Contemplative Experience paper discusses causal attribution criteria in greater detail (see https://doi.org/10.1371/journal.pone.0176239 page 28), and subjective judgement of causality is just one of eleven factors used in that study to determine causality.

In discussing causality for this study it is overstretching to talk about a causal relation between meditation method and PLEs. It would be good to consistently use language like “perceived causality” should be used to discuss the finding that participants felt that a method of meditation was causing the experience of a PLE. Additionally, these questions should not be asked of participants who have not had a PLE, because their inclusion in the data skews your results further toward hypothetical perception of a relationship, rather than an empirical one, derived from first-hand experience of those who have had one. You also imply that this relationship is a fact of which participants are subjectively aware in the first paragraph of the discussion. There is not sufficient evidence for this claim.

Operationalise Your Terms

It would be good to clearly define, for the sake of the study what definitions you’re using for mystical experiences and PLEs. You do explore the idea that PLEs are the positive aspects of psychosis in a parenthetical statement in your intro, but less discussion is given to what a mystical experience is—perhaps the working definition of both terms is the same and you’re curious how survey participants define them differently. Add a paragraph or two explicitly operationalising your key terms, what working definition you used, and how you measured it (in addition to your later section that describes each of the scales). This is done somewhat in the section called “Differences Between Mystical Experiences in Subjects Distress and Positive Ratings,” but not sufficiently. Are there positive and negative mystical experiences, or have you defined a mystical experience as a positive PLE?

There is not sufficient treatment of the PLEs at the same time being desirable and a source of insight on the one hand, and on the other, constituting a risk against which certain methods of meditation constitute a protective factor. It would be appropriate to address why some people are seeking PLEs/mystical experiences, and some people may wish to avoid them.

Document Layout

Please list your hypotheses more clearly at the end of the introduction (as you have done in the pre-registration).

The number of participants that completed the survey is part of the results, in the methods section please explain the study participant selection criteria (eg how did you define “meditator” – was there a minimum required amount of practice?).

What did you use the motivation to meditate data for? Please clarify.

Have your study design precede the description of participants and scales rather than follow them. Also, please clarify what happened to the follow-up questionnaire. You don’t seem to report any results on it.

Limitations

There is no discussion of the limitations of this study. In your discussion section you talk about the implications and potential application of findings, but there should also be a paragraph that talks about the limitations of causal inference especially in relation to the type of study (cross-sectional survey) and its claims.

You have conducted several statistical analyses, and have not controlled for multiple testing (false discovery rate). Therefore, some of the associations that you found may be spurious, which needs to be acknowledged as a limitation. This is the most important limitation of your work, so please mention it both in the text and in the abstract.

You should also address the degree to which the categories of meditation method are arbitrary and may overlap or be mutually exclusive, as well as any efforts made toward inter-rater reliability in classification of meditator’s self-description of their meditative goals and techniques, as it appears this may have only been done by author TP. Were there any limitations due to your sample population or approach to recruitment? You state that 613 participants completed at least parts of the survey. How many completed the whole survey, and are there any limitations due to the number that completed it only in part?

If you have collected your data before registering your analysis plan, unfortunately this does not technically count as pre-registered (even if you have not analysed your data before registration). Please acknowledge this as a limitation.

You wanted to recruit 1000 participants in order to have a large enough sample size to have participants address 50 different techniques, are there any limitations in the fact that you recruited just over 600? Did you have to make any adjustments in the study design to accommodate this change in sample size?

Also, the Dahl classification was not preregistered, please acknowledge this.

Statistical Analysis

It is not clear why you have used the model comparison technique rather than simply looking at the beta coefficients of the predictors of interest in the full multiple regression model. And what statistical test do the t values reported correspond to (ie exactly what are you comparing)? I am not sure you are actually testing what you want to test. Looking at the beta coefficients of your predictors would be a much more direct way (and possibly the only correct way – I am not a statistician) to test your hypotheses.

You mention that you are not presenting all your results (eg other questionnaires) due to constraints on word count, but PLOS ONE does not have any word count constraints, so please include all your results.

Reviewer #2: I appreciate the opportunity to review the manuscript under consideration for publication entitled “Differential relationships between meditation methods and psychotic-like and mystical experiences.” The manuscript is well written and provides novel and important findings for the relationship between meditation practices and psychotic-like experiences. The grouping of meditation practices into different taxonomies is an especially strong characteristic of the study, and allows for a more nuanced picture of the relationship between types of meditation practices and altered state experiences. I am not aware of any prior publications that have conducted such an analysis. Furthermore, the analytic plan is strongly designed and the results are convincing. I believe that this paper provides important information that could be used to identify and monitor risks for adverse effects of meditation. As a result, I recommend this paper for publication considering that the authors address the concerns outlined below:

1. My primary concern is that the manuscript presents an overly simplistic narrative about the relationship between mystical experience and psychotic-like experiences. For example, the discussion in the second to last paragraph of the introduction on the relationship between mystical experience and psychotic-like experiences could benefit from a more critical analysis of the construct of mystical experience (see Taves, 2020). Mystical experience and psychotic-like experiences both represent altered states; however, the mystical experience scale conflates these states with positive affect and positive appraisals, while the measure of psychotic-like experiences that this manuscript uses likely does the opposite. Therefore, it is unsurprising that these two measures of altered states are related to each other (as the results found). Furthermore, differences may be more representative of whether these altered states co-occur with positive or negative affect and/or interpretations (though phenomenology may vary between the scales too). I would like to see more discussion of the similarities and differences (in terms of phenomenology, affect, interpretation) between mystical experience and psychotic-like experience regarding both the general constructs and the specific measures used.

Taves, A. (2020). Mystical and Other Alterations in Sense of Self: An Expanded Framework for Studying Nonordinary Experiences. Perspectives on Psychological Science 15(3), 669-690. https://doi.org/10.1177/1745691619895047

2. I would also like to see more description of the interoception and decentering scales used in the manuscript. Given that these scales were designed to measure adaptive psychological skills, I think it is important to note that they were not designed to be neutral in terms of mental health but instead to measure inherently healthy processes. For example, the MAIA contains the item “I feel that my body is a safe place.” While I do not think that this presents a problem for the present findings, I do think that it is important to note that that these scales are not measuring body awareness and cognitive distancing as unbiased meditation-related processes, but as inherently psychologically healthy skillsets in relation to such processes.

3. For all measures, it would be helpful to include a more thorough description (e.g., subscales, total score) and example items to illustrate what the measure is capturing. I believe that this is important given that the results are dependent on the measures used.

4. When reporting regression results, I would like to see some measure of effect size, such as standardized beta.

5. The columns in Table 1 (during meditation QUs and Psychosis Proneness QUs) are hard to follow without reading the methods section in detail, which is provided much later in the manuscript. I am still not sure what QU stands for and would like to see this defined in the table note. I would also like to see the three samples described in more detail in the table note, as well as how these differing number of participants relate to the analyses conducted.

6. I would also like to see more description of table 2, either in the table note or the results section text, as I find this table hard to follow as well. Please specify exactly what the colors mean and how the rows are organized. It would be helpful to specify that “top positively correlating techniques” refers to correlation with PLEs. I am still somewhat confused by what “techniques used in study” refers to exactly (weren’t all of the techniques used in the study)?

7. Finally, the description of the interaction results is confusing. The sentence “Our results showed interaction between NDM and PLEs in daily life was significantly negative (t207 = -2.78 p = <.01), and positive for ADM and PLEs (t207 = .3.13 p = <.01) (S1 Table 9, Fig. 3D)” seems to be reporting a moderation analysis; however, I think more information is needed to understand this statement. I believe that moderation would involve three variables but I only see mention of two variables in this sentence.

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Reviewer #1: No

Reviewer #2: Yes: Nicholas K Canby

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PONE-D-23-11057R1Differential Relationship Between Meditation Methods and Psychotic-Like and Mystical ExperiencesPLOS ONE

Dear Dr. Palmer,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. As you can see from the comments of both reviewers, there are major methodological and theoretical issues that need to be addressed. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Mar 08 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Rakesh Karmacharya, MD, PhD

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: (No Response)

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: I Don't Know

Reviewer #2: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: No

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1:

 Thanks again for inviting me to comment on this interesting work. This new version represents significant progress. The authors have worked hard adding important information in a number of places. I am afraid, however, that the manuscript needs further work, as detailed below.

• The paper is very hard to parse, it needs more attention in order to avoid confusion. For example, some methods are explained in the introduction and in the results. Also, results are presented without introducing them in methods: Table 2 presents pearson correlations not introduced in the methods or linked with anything else.

• Plos One papers have the methods before the results, please move them.

• Regression weights and coefficients are not the same, please use word coefficients consistently.

• Please clarify in the methods that the t tests are on regression coefficients. As far as I understand, what is usually reported in regressions is the standardised beta coefficient and the p value, not the t value. And why are effect sizes calculated using partial eta squared and not simply interpreting the regression coefficients? I suggest you report the beta coefficients instead of the t values, as they are more interpretable. it is good practice to report 95% confidence intervals too.

• Have the authors tested whether regression models were meeting statistical assumptions (eg distribution of residuals, etc)? There is no mention of this important aspect that can invalidate results if assumptions are not met.

• Reasons for meditating seem to have been classified into two factors, but there is no explanation of what these factors are (only variable names in the graphs).

• Regarding making causal claims about meditation type and PLEs: The section on hypothesis 1c seems clear with regards to perceived causality, but in the Discussion (on page 3) authors argue they have evidence for causality, " We also found that participants were subjectively aware that the different meditation methods have different relationships to adverse experiences, that we term ‘perceived causality’." this should rather be stated, "Although cross-sectional survey data can't prove a causal relationship between meditation type and PLEs, we have found that meditators perceive that different types of meditation may be more likely to elicit PLEs than others."

• They have a much better discussion of the potential connections and differences between mystical experiences and PLEs.

• I'd encourage them to use one word like "perceive" just in context of subjective causal attribution and different word like "appraise" in terms of subjective valence (pos/neg), otherwise. For instance this sentence on the top of page 10, "For mystical experiences, people who experienced more PLEs perceived mystical experiences as more distressing (t138 = 2.95, p <.01, S20), with no difference (or even an opposite trend) to how positively they were perceived."

• The limitations section needs much more thought. Important ones that are not mentioned, are that the cross-sectional nature does not allow to understand the temporal sequence of factors, and that these relationships can all be confounded by unmeasured factors. Both have important implications that need to be reflected upon and discussed.

Reviewer #2: 

The authors have extensively reworked this manuscript, and these changes have led to a significant improvement. However, a number of problems remain which I would like to see addressed before recommending this manuscript for publication. 

1. General comments:
   1. While some of the additional information provided in this version of the manuscript is important, some of the sections have become quite wordy and excessively long. For example, the scale descriptions in the methods section are an important addition, but need to be further edited to be more concise and parsimonious. Similarly, the analysis section of the methods feels excessively long and in need of further editing. I would like to see this section written in full sentences and paragraph form. 
   2. The manuscript could benefit from additional proofreading, as there are awkward sentences, typos, and grammatical errors throughout. 
   3. The header structure is at times unclear and confusing. For example, in the methods section, it appears (but I’m not sure) that “Questionnaires Included” is a separate section after “Materials and Measures.” I would recommend using a more standard header structure and providing some additional subheaders in the introduction and discussion. For example, the transition from the second to third paragraph of the introduction feels very abrupt and could either benefit from a header or further editing. 
   4. The new sections of the introduction on the valence of psychotic or mystical experiences also seem unnecessarily long for this point in the introduction (see additional comments below about this novel section). As a general point, I think the introduction needs additional framing to contextualize some of the results that are not introduced at all in the introduction, while this novel section is important but currently overrepresented in the introduction. 
2. Theoretical Issues:
   1. There are theoretical problems in the novel section of the introduction about the valence of psychotic and mystical experiences. Unfortunately, the authors seem to have misunderstood my previous point about the overlap between mystical and psychotic-like experiences. Page 3 of the introduction discusses the incidence of distress vs. “personally transformative growth” as a result of psychosis. However, this conflates the general construct of “psychosis” with the specific CAPE-42 items about hallucinations and delusions that this study uses as its measure of PLEs. “Psychosis” is already a pathologizing term, and as a clinical diagnostic category, it is defined in terms of functional impairment or distress. Instead, I would like to know whether the CAPE-42 items used in the current study are worded in a way that assumes/implies they are negative/pathological or whether they are phenomenologically neutral. This is important, as visions and magical thinking (another way of phrasing hallucinations and delusions) are valued in many spiritual traditions. If the items are neutrally worded, it is therefore unclear whether they are measuring something innately pathological or not. 
   2. The next paragraph about mystical experience in the introduction has the same theoretical problems. Given that this study uses the MEQ30 to measure mystical experiences, mystical experiences should be understood as whatever is being measured by these items (which notably do not include the word God). Therefore, I would like to see the discussion of mystical experiences less tied to an abstract notion and more related to what is specifically being measured in this study. More importantly, the MEQ includes positive affect in its definition, which makes a discussion of whether mystical experiences are positive for some people or distressing for others nonsensical when based on this measure and definition, given that the construct is defined as being innately positive. I would encourage a critique of the way that mystical experiences have been defined, perhaps in the discussion or limitations, but given that this definition is already being used, it does not make theoretical sense to discuss its valence. Finally, please replace the Parnas & Hendriksen citation with a more up-to-date citation on the sense-of—self-related similarities between mystical and pathological experiences or leave out this citation entirely, as current scholarship on the topic has advanced considerably since this was published. 
   3. Here is what I would recommend in response to these issues: introduce the MEQ and CAPE-42 as being innately biased toward positive or negatively valenced experience (if that is also the case for the CAPE-42) and comment on how they share some common phenomenology (if they do, at the item level). Then, throughout the rest of the paper, frame PLEs and mystical experience as related but each biased toward pathological/negative appraisals or spiritual/positive appraisals.  Finally, the “exploratory analysis 2: differences between mystical experiences in subjects distress and positive ratings” should be removed, as it is redundant to ask about the valence of mystical experiences when the measure already includes positive affect. 
   4. The section on the discussion that covers these topics also needs to be edited based on the issues identified above. Please discuss what is actually being measured in this study rather than assuming that it refers to broader abstract concepts. For example:

i.The sentence “It could be argued that mystical experiences are not necessarily positive or negative and in many cases might be neutral” doesn’t make sense when mystical experiences are defined as involving positive affect, though authors have pointed out that this definition is problematic (see Taves, 2020).  

ii.“PLEs and mystical experiences overlap in terms of their link to altered experiences of self” – please specify if this is the case, and if so which experiences of self, for the two specific measures used in this study. 

iii.Likewise, please link the discussion of interoception more closely to the specific items/subscales used to measure interoception. For example, feeling safe in one’s body might not be the same thing as the felt sense of presence in one’s body (see self review article: Britton et al., 2021). There are many forms of interoception and it is problematic to assume that the measure that this study uses for interoception corresponds to theoretically different conceptualizations of interoception. 

1. Issues with framing the results:
   1. The hypothesis section of the introduction feels quite lengthy and many of the hypotheses were not framed or supported in the introduction until that point. I am confused by why there is a paragraph describing hypotheses and then a long list of many of the same hypotheses below. Maybe the longer list could be moved to supplemental materials. I also think 1a, 1b, and 1c could be condensed into a single paragraph perhaps. 
   2. I am confused about why the methods section is below the results and discussion. I think it would be easier to follow the results if I understood the methods first, especially the measures section (with example items to illustrate exactly what is being measured). 
   3. In the results section, I think it would read better if much of the information in the table/figure captions was moved to the body text. The table/figure captions are very long and hard to follow and the paragraphs do little to introduce the tables/figures. 
   4. I think the paper would benefit from more introduction and framing of the exploratory results section. I would like to see some framing in the introduction that prepares the reader for these results, introduces the concepts of interoceptive awareness, decentering, and reasons for meditating and why they might be important for the research questions. 
   5. The limitations section is quite short and could include quite a lot more. I’d like to see more limitations about the sample (how accurately does it generalize to a larger population), the analyses used, the measures used, and the theory that distinguishes mystical experiences from psychosis. Finally, I’d like to see a conclusion section after the limitations.

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[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PONE-D-23-11057R2Differential Relationship Between Meditation Methods and Psychotic-Like and Mystical ExperiencesPLOS ONE

Dear Dr. Palmer,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. As both reviewers note, the quality of the manuscript has improved significantly. Your revised manuscript has addressed all the issues raised by Reviewer 1 as well as many of the issues raised by Reviewer 2. There are a few important issues that remain in relation of the concerns raised by Reviewer 2, as described below, many of which are related primarily to the style and presentation of the content in the manuscript and a few missing details.  

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We look forward to receiving your revised manuscript.

Kind regards,

Rakesh Karmacharya, MD, PhD

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: (No Response)

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: (No Response)

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: (No Response)

Reviewer #2: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: (No Response)

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

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Reviewer #1: (No Response)

Reviewer #2: No

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: All my comments have been addressed, thank you. I look forward to seeing this manuscript published as it will be an interesting contribution to the field.

Reviewer #2: Thank you for the opportunity to review this interesting manuscript. This revision represents a significant improvement over the previous draft. The authors have clearly put a lot of work into responding to the comments from the previous round of revisions. Many of the technical and theoretical issues have now been sufficiently addressed in my opinion. Furthermore, the results of this study are interesting, important, and novel. I believe that the study does merit publication. Unfortunately, however, I still think it needs significant work in the following areas before it is ready for publication:

Writing quality: the manuscript needs a great deal of further proofreading and formatting.

1. There are still grammatical issues, run-on sentences, and spelling mistakes throughout the manuscript. For example, decentering is spelled incorrectly on second page of introduction, “and” is spelled incorrectly in the title of Table 2, capitalization is inconsistent, etc.

2. The manuscript needs additional formatting according to APA style or other journal standards. For example, sentences should be in past tense, tables and figures should be referenced and contextualized in the text, and headers should be structured in a more standard way with main headers and subheaders

3. Acronyms should be introduced first with the full name (e.g., CAPE-42 in the introduction).

4. The language in many places needs to be clearer and more precise. For example, please clarify differences between “related to, linked to, defined as, correlated with” which seem to be used interchangeably at times (especially in second page of introduction). Describing how a construct is defined should be clearly delineated from describing what it is correlated with.

5. The study should not repeat so many times that it is pre-registered. This can be mentioned in the methods once. Also, avoid language like “a very large sample” and instead just state the size of the sample.

Introduction:

1. I feel that the introduction still needs some work as it is too focused on describing the present study rather than introducing the concepts and theory necessary to contextualize the present study. There are a number of sentences in the introduction that would be better placed in the methods or results. For example on page 1, the following sentence describes the study method and should not be in the introduction: “Here, we examined the impact of different types of meditation methods on PLEs. To allow statistical tests, we grouped them according to a taxonomy proposed by Nash, Newberg and Awasthi.” The last sentence in the introduction is about the results and should be moved to that section.

2. The introduction needs to introduce and describe the concepts more clearly. For example, what is an enhanced cognitive state? Why are MBSR and MBCT considered CDM meditation (and how do you know this since these interventions involve multiple techniques)?

3. The first paragraph of the second page about reasons to meditate provides little theory or context and instead focuses on the study’s research questions. Why are reasons for meditating important? What do other studies show about reasons to meditate?

4. Given the importance placed in Table 2 on the three different meditation taxonomies, I think these need to be described in more detail in the introduction in order to provide more context for the rest of the paper.

5. The concepts of decentering and interception are very briefly mentioned and also need to be further defined. Why would these core mechanisms possibly relate to PLEs? Why are these considered core mechanisms?

6. I think the introduction could say something more about the effects of meditation on altered states. The framing of the first paragraph says that the study looks at the links between different types of meditation and adverse and beneficial outcomes. While this is technically correct, it feels a bit odd not to mention that both of these outcomes (PLEs and mystical experiences) are types of altered states. In general, I think the introduction could benefit from a more in-depth literature review, which would also improve the quality of the discussion.

Methods:

1. Analyses section of methods should be under a single header with subheaders for the various types of analyses.

2. Questionnaires should be a subheader under materials and methods. Techniques, traditions, reasons for meditating, and each individual questionnaire don’t need separate headers.

3. Questionnaire descriptions are awkwardly written and formatted

4. Please include a bit more about the recruitment strategy. How was the study advertised? This has an impact on the sample characteristics and should also be referenced in the limitations (about how the sample might not generalize to all people).

Results:

1. Demographics: what about race, ethnicity, nationality, first-language, sexual orientation?

2. I still feel that the tables and figures need to be better referenced in the text and more clearly described. Table 2 contains useful information but it presents so many different categorical systems that it took me some time to make sense of. I think this table in particular needs to be better described in the text.

Discussion:

1. The discussion doesn’t mention anything about interoception or decentering. I think these should be discussed since they’re part of the results.

2. In general, the discussion could use more integration with the other literature and theoretical considerations instead of just a summary of the results. Why is body focus important? Why is null focus important? Why do you think reasons for meditating are important?

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Reviewer #1: No

Reviewer #2: Yes: Nicholas K Canby

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Differential Relationship Between Meditation Methods and Psychotic-Like and Mystical Experiences

PONE-D-23-11057R3

Dear Dr. Palmer,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Kind regards,

Rakesh Karmacharya, MD, PhD

Academic Editor

PLOS ONE

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Reviewers' comments: