PONE-D-19-25269

Questioning the lasting effect of galvanic vestibular stimulation on postural control

PLOS ONE

Dear Ms Nooristani,

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.

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Nicolás Pérez-Fernández

Academic Editor

PLOS ONE

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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: Yes

Reviewer #2: Yes

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

Reviewer #1: Yes

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: No

Reviewer #2: Yes

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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 an important and well performed study. This is a critical addition to the literature to reduce noise in the literature- as experiments must be performed with controls conditions or SHAM stimulation in brain stimulation studies.

Reviewer #2: It is a very nice and useful paper, which is also agreeable to read. However, soe corrections need to be implemented before publication. In particular the interpretation of the results needs to be improved.

Introduction

“Galvanic vestibular stimulation (GVS) is a technique used to stimulate the vestibular

system by applying an imperceptible level of electrical current through electrodes placed”

No, GVS can be perfectly perceptible, it depends of the intensity. Please correct.

Pease mention that GVS stimulate all vestibular sensors and the nerve. You should also quote adequate reviews on GVS in this first paragraph.

“postural enhancement” please be more precise

“might be caused by a learning effect.” Why do you exclude a placebo effect at that point?

Methods

“Research approval was obtained from the Institutional Review Board of the Faculty of

Medicine at the Université de Montréal, and informed written consent was provided by

all participants.” Pease give the IRB number, the exact reference of the ethical panel and the date of approval.

“Participants had to perform a static postural control assessment, standing on a foam

surface (AIB Balance Foam, AIB, USA) placed on a force plateform (Accusway, AMTI,

USA) with their eyes closed. Three runs of 60 seconds CoP sway measurement were

performed at three different measurement time points i) prior to stimulation (baseline), ii)

immediately after the end of stimulation (T0: 0h post-stimulation) and iii) one-hour poststimulation

(T1: 1h post-stimulation). The CoP parameters recorded were sway velocity

and path length; they were analyzed using Balance Clinic software (AMTI, USA).”

You never discussed in the introduction or here

• why you choose 60 seconds, using the foam,

• one hour of stimulation

• why the subjects were stimulated in a sited position and their posture tested in a standing position

Alternative choices were available. Also were the subjects barefoot?

“Therefore, it was not possible for the participant to determine if they received the sham or the real stimulation.”

How did you check that?

Results

No remark

Discussion

“As expected, our results revealed that postural stability following 30 minutes of nGVS resulted in a significant sustained improvement post-stimulation.”

Why is it certain that decreasing postural sway is an “improvement of stability”, at the very least in healthy subjects? It could be also an incidental effect in patients and why it is so sure that it is beneficial? Postural sway could be useful in many ways: exploring the limits of the polygon of sustentation, decreasing the risk that the plantar sol receptors become desensitized etc. Please delete that terminology, which is biased in the discussion and discuss these points. For instance, it could be some sort of freezing reaction, which explains why it was observed in the nGVS group.

In the conclusion, one should insist also of comparing the effect of GVS with sham procedures in vestibular patients.

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Reviewer #1: No

Reviewer #2: No

[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 to be viewed.]

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PONE-D-19-25269R1

Questioning the lasting effect of galvanic vestibular stimulation on postural control

PLOS ONE

Dear Ms Nooristani,

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.

We would appreciate receiving your revised manuscript by Nov 24 2019 11:59PM. When you are 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.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

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). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Nicolás Pérez-Fernández

Academic Editor

PLOS ONE

Additional Editor Comments (if provided):

Still comments 8 and 11 from Reviewer 2 must appear on the final text.

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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 #2: All comments have been addressed

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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 #2: Yes

**********

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

Reviewer #2: Yes

**********

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 #2: Yes

**********

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 #2: Yes

**********

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 #2: Thank you to have answered to my question. Please explain in the text and not only to me

- Why the subjects were stimulated in a seated position and their posture tested in a standing position?

- Why is it certain that decreasing postural sway in an “improvement of

stability”, at the very least in healthy subjects? It

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

[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 to be viewed.]

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 us at figures@plos.org. Please note that Supporting Information files do not need this step.

Questioning the lasting effect of galvanic vestibular stimulation on postural control

PONE-D-19-25269R2

Dear Dr. Nooristani,

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

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With kind regards,

Nicolás Pérez-Fernández

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

The authors have made a complete review now of the manuscript

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