PONE-D-23-26564Distinct age-related brain activity patterns in the prefrontal cortex when increasing cognitive load: a functional near-infrared spectroscopy studyPLOS ONE

Dear Dr. Gonzalez,

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.

ACADEMIC EDITOR: Reviewers have suggested some minor changes. Authors are encouraged to revise upon reviewers' comments and submit the revised version.

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We look forward to receiving your revised manuscript.

Kind regards,

Noman Naseer, PhD

Academic Editor

PLOS ONE

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2. Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Additional Editor Comments (if provided):

Reviewers have suggested some minor changes. Authors are encouraged to revise upon reviewers' comments and submit the revised version.

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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: 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: 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: The researchers used functional near-infrared spectroscopy to measure prefrontal cortex activity during single and dual N-back tasks in a group of 27 young adults and 31 older adults. The findings revealed that there were performance differences between task load conditions, and older adults exhibited slower reaction times, but both age groups showed similar levels of accuracy. Importantly, older adults displayed increased bilateral PFC activation across all tasks and even more brain activity during high-load conditions compared to low-load conditions. This study suggest that older adults continue to use compensatory recruitment of additional PFC brain regions to maintain cognitive performance, even at higher cognitive loads.

Congratulations to the authors of this study. I have thoroughly enjoyed reading this manuscript. The manuscript is formally clear, providing a well-structured and up-to-date review of relevant literature on the topic. Both the research objectives and methods are clearly articulated. The results are well-documented and effectively illustrated. The discussion comprehensively addresses key aspects arising from the study's findings.

After thoroughly reviewing the manuscript, I have only identified a few minor points related to the formatting of certain cited works.

Page 30 and reference number 31: date is May 9

Page 31 and reference number 43: please remove the duplicated page.

Reviewer #2: Summary Statement:

The present study aimed to examine age related differences in PFC activity utilizing fNIRS and cognitive performance (accuracy and RT) during 2-back visuospatial only and 2-back dual with visuospatial and audio. The authors found that older adults exhibiting more bilateral PFC activation was used as a compensatory mechanism to maintain cognitive performance. Accuracy was unaffected in OA; however, RT was slower, which may be due to OA focus on performing accurately. Overall, the results of the work is well written and organized appropriately and is of interest of the field of neurocognitive aging research. Statistical tests are appropriate. Technical aspects of the paper and scientific rigor are sufficient. Overall, this work will make a significant contribution to neuroscience aging research as the hemodynamic response in aging provides conflicting results, as described by the authors. Minimal critiques are presented below:

• Need a clear rationale for why RT that were less than 80ms were removed.

• Stated that authors used FDR corrections but then indicate that significance is set at p<0.05- this either needs to be changed to q<0.05 or mentioning FDR corrections needs to be removed.

• Tables P-values right column, the > sign should be changed to <0.001.

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Reviewer #1: No

Reviewer #2: Yes: Cameron D. Owens

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Distinct age-related brain activity patterns in the prefrontal cortex when increasing cognitive load: a functional near-infrared spectroscopy study

PONE-D-23-26564R1

Dear Dr. Gonzalez,

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.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Noman Naseer, PhD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Associate Editor: The paper has been revised well upon reviewers' comments.

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: 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 #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?

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: (No Response)

Reviewer #2: Yes

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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: I have reviewed the revised manuscript and I report that the authors have effectively addressed my previous concerns and suggestions. The manuscript has been substantially improved, and I recommend it for publication.

Reviewer #2: (No Response)

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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 #1: No

Reviewer #2: No

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