Gaze-behaviors of runners in a natural, urban running environment

Mark M. Cullen; Daniel Schmitt; Michael C. Granatosky; Christine E. Wall; Michael Platt; Roxanne Larsen

doi:10.1371/journal.pone.0233158

Peer Review History

Original SubmissionMarch 10, 2020
16 Apr 2020 Decision Letter - Nizam Uddin Ahamed, Editor PONE-D-20-07008 Gaze-Behaviors of Runners in a Natural, Urban Running Environment PLOS ONE Dear Mr. Cullen, 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 May 31 2020 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, Nizam Uddin Ahamed, PhD Academic Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 1. Please amend your manuscript to include your abstract after the title page. 2. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. [Note: HTML markup is below. Please do not edit.] 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 ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 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 ****** 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 ****** 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 study attempts to answer the question of whether runners fixate on obstacles such as sidewalk curbs when running in an urban road setting. To answer the question, authors followed a dual-process visual control framework, used a binocular gaze-tracker, and developed a customized algorithm to test gazing behaviors among runners in two primary hypotheses. Results showed that runners tended to use a combination of online and feedforward sampling control strategies and that faster average running pace led to fewer fixations on the obstacle of sidewalk curb. In many ways the manuscript is interesting, particularly regarding the development of customized eye-tracking algorithm in dealing with visual fixations on objects in 3D space. It is also well written. With that said, I do have several concerns that could help enhance the manuscript. The concerns were elaborated below. First, I have concerns about employing the current eye-tracking system in a running task. Based on what I can find given the information authors provided, the eye-tracking system seems to involve infrared (IR) reflection lenses (i.e., the hot mirrors) in tracking the eyes. Such a design of IR lenses, compared to those embedded in the glasses frames in some other eye-tracking brands, may be less fit to studying the running task. It is because running movements involve constant bodily acceleration that can dislocate previously calibrated IR reflection lenses, which is usually connected to the glasses frame via weak plastic connectors. I understand that, if I am correct about the hardware, the authors may have limited power in attenuating the above issue associated with the equipment design, but I encourage them to fully acknowledge such difficulties and include a picture of the exact eye-tracking system used. Another challenge of tracking runners’ vision comes from the fact that runners generally need to keep their upper bodies (including heads) relatively stable during running to maximize movement efficiency. That is, keeping the head still during running requires more visual search to be achieved by replacing head movements with eyeball movements, which makes the pupils more likely to appear at off-center locations in the eyes. For the majority of eye-tracking systems utilizing the ‘pupil to CR (corneal reflection)’ technique, big eyeball movements would cause technical issues by making the IR dots more likely to fall off the pupil region and by reshaping the appearance of the pupil from a circle to a oval shape, which is harder for the algorithm to recognize. That is to say, the task would cause increased likelihood for tracking loss. Although authors reported the inclusion criterion of 84% (l.223), I worry about potential dependence between tracking loss and gazing behaviors in the running task, which can result in bias regarding evidence analyzed and conclusions. I would encourage authors to do some analyses comparing those low-tracking rate trials (e.g., the lowest 6 trials) with the current evidence analyzed so that we can either eliminate or confirm such a possible bias, either way it would be a contribution. Furthermore, although the authors did a good job reviewing literature of foveal vision in relevant task models (to some extent, I feel that the authors overly cited the literature in several locations in the Introduction, so I suggest to cut off some redundant ones), the literature on peripheral vision is largely missing. It makes sense that the foveal vision should be a focus of literature review given the use of eye-tracking, which is really foveal vision tracking. However, visual attention can come from or even be dominated by peripheral vision. It is likely that in some instances runners rely more on peripheral vision in monitoring environments. I would recommend authors give a light weighted review (and also discussion) on peripheral vision. A recent review from Vater et al. would be a good start place. Vater, C., Williams, A. M., & Hossner, E. J. (2019). What do we see out of the corner of our eye? The role of visual pivots and gaze anchors in sport. International Review of Sport and Exercise Psychology, 1-23. Since the algorithm is supposed to be a major contribution of the manuscript, I have some suggestions to enhance it: 1. try to include Goodman and Kruskal’s Lambda in addition to Cohen’s Kappa. Lambda could give another view of the ‘rater agreement’; 2. explicitly acknowledge the small number of frames (i.e., 20, l. 279) used in testing the algorithm and encourage future studies to increase it. Such a small number may generate biased Kappa and Lambda estimates and is subjected to selection risks (i.e., why this 20 out of potentially hundreds of frames? why not randomly draw from the pool of available frames?). Lastly, I have some comments on the results section. Authors non-parametrically tested a small sample (n=10). None of the results in Section 3.1 and 3.2 reached significance (p < .05), which is not surprising given the compromised statistical power from both directions. The only significant results came from a parametric test (e.g., simple regression) in Section 3.3. To be consistent in authors’ testing approach, shouldn’t they replace the a simple regression (which basically gave estimates on Pearson r) with Spearman Rank correlation estimates? Reviewer #2: The study tackled an interesting topic on gaze behavior of the runners in facing the natural obstacles in terms of pre-planning vs. online planning which is important to the respective field, the statistical analyses and results were sound and the manuscript was well-written. ****** 6. 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. https://doi.org/10.1371/journal.pone.0233158.r001
Revision 1
24 Apr 2020 Author Response We want to thank the editor and the two anonymous reviewers for comments and suggestions. We were able to accommodate every suggestion and we think that the changes we made have improved the manuscript. We are grateful for the opportunity to submit a revised version and hope that you find this manuscript acceptable for publication. Reviewer #1: The study attempts to answer the question of whether runners fixate on obstacles such as sidewalk curbs when running in an urban road setting. To answer the question, authors followed a dual-process visual control framework, used a binocular gaze-tracker, and developed a customized algorithm to test gazing behaviors among runners in two primary hypotheses. Results showed that runners tended to use a combination of online and feedforward sampling control strategies and that faster average running pace led to fewer fixations on the obstacle of sidewalk curb. In many ways the manuscript is interesting, particularly regarding the development of customized eye-tracking algorithm in dealing with visual fixations on objects in 3D space. It is also well written. With that said, I do have several concerns that could help enhance the manuscript. The concerns were elaborated below. We want to thank the reviewer for their compliments and the suggestions for ways to improve the paper. We have been able to take all these suggestions into account and believe that the paper is significantly improved. First, I have concerns about employing the current eye-tracking system in a running task. Based on what I can find given the information authors provided, the eye-tracking system seems to involve infrared (IR) reflection lenses (i.e., the hot mirrors) in tracking the eyes. Such a design of IR lenses, compared to those embedded in the glasses frames in some other eye-tracking brands, may be less fit to studying the running task. It is because running movements involve constant bodily acceleration that can dislocate previously calibrated IR reflection lenses, which is usually connected to the glasses frame via weak plastic connectors. I understand that, if I am correct about the hardware, the authors may have limited power in attenuating the above issue associated with the equipment design, but I encourage them to fully acknowledge such difficulties and include a picture of the exact eye-tracking system used. Thank you for your comment. This was a major concern for us as well. Yet we really wanted to expand the use of these systems into dynamic settings and we hope we made adjustments that make this system work well. The current system is the most modern designed by iScan and we worked with them to make it as sturdy as possible for this goal when we purchased. In addition, we designed the helmet with the tight fitting band on the head that limited movement and firmly affixed the glasses in places (without discomfort). We have inserted a new figure, Figure 2 in the manuscript, of one of our authors (MC) wearing our gaze-tracker, helmet and backpack. We did all our runs at dusk and dawn to minimize outdoor light exposure. We have expanded on that in the methods (starting on line 194) and have acknowledged these limitations in our methods and discussion (line 458-461). In addition, recognizing the limits we considered larger regions of gaze (the curb broadly speaking and with error incorporated) to avoid some of those issues. We hope the reader will consider these limitations and that future studies will further address design. Another challenge of tracking runners’ vision comes from the fact that runners generally need to keep their upper bodies (including heads) relatively stable during running to maximize movement efficiency. That is, keeping the head still during running requires more visual search to be achieved by replacing head movements with eyeball movements, which makes the pupils more likely to appear at off-center locations in the eyes. For the majority of eye-tracking systems utilizing the ‘pupil to CR (corneal reflection)’ technique, big eyeball movements would cause technical issues by making the IR dots more likely to fall off the pupil region and by reshaping the appearance of the pupil from a circle to a oval shape, which is harder for the algorithm to recognize. That is to say, the task would cause increased likelihood for tracking loss. Although authors reported the inclusion criterion of 84% (l.223), I worry about potential dependence between tracking loss and gazing behaviors in the running task, which can result in bias regarding evidence analyzed and conclusions. I would encourage authors to do some analyses comparing those low-tracking rate trials (e.g., the lowest 6 trials) with the current evidence analyzed so that we can either eliminate or confirm such a possible bias, either way it would be a contribution. Thank you for your comment and we feel that this is a great point. We went through all of our trials that were excluded either because they were not at the correct portion of the run (beginning, middle, or end) or did not meet our 84% inclusion criteria. We found that 49% of our rejected trials met the 84% or greater inclusion criteria. As a result both low and high cursor trials were excluded. When we expanded this to 80%, it included 71% of our sample, and finally when expanded to 75%, this included 96% of our sample. We hope that this data shows that the trials that were excluded had the crosshair present for a similar amount of time as the trials we included and that often it was the time of the run (beginning, middle, and end) that determined what trial was chosen rather than a trial having the highest percentage of crosshair presence. The statement “For those with more than six, the trials with the six highest percentages of crosshair presence were included,” has been removed and the methods (lines 236- 247) have been modified to reflect that fact that trials were chosen from the beginning, middle, and end of the run, and that each of these met our 84% inclusion criteria. We would like to emphasize that this does not mean that the trials chosen for a particular individual included the highest percentage of crosshair presence, it was the fact that it met our criteria of having the crosshair for greater than 84% of the trial and the trial was at the correct portion of the run. Furthermore, although the authors did a good job reviewing literature of foveal vision in relevant task models (to some extent, I feel that the authors overly cited the literature in several locations in the Introduction, so I suggest to cut off some redundant ones), the literature on peripheral vision is largely missing. It makes sense that the foveal vision should be a focus of literature review given the use of eye-tracking, which is really foveal vision tracking. However, visual attention can come from or even be dominated by peripheral vision. It is likely that in some instances runners rely more on peripheral vision in monitoring environments. I would recommend authors give a light weighted review (and also discussion) on peripheral vision. A recent review from Vater et al. would be a good start place. Vater, C., Williams, A. M., & Hossner, E. J. (2019). What do we see out of the corner of our eye? The role of visual pivots and gaze anchors in sport. International Review of Sport and Exercise Psychology, 1-23. Thank you for the reference this helped us really consider this issue. We have added references to the manuscript and have added to our introduction more on peripheral vision during the approach (lines 118-121) and have emphasized its importance during clearance of the obstacle (lines 121-122). We added a sentence on the need for further exploration of the study of peripheral vision in running to better characterize our understanding of the approach and navigation of obstacles as human’s run toward them in the discussion (line 465-467). Since the algorithm is supposed to be a major contribution of the manuscript, I have some suggestions to enhance it: 1. try to include Goodman and Kruskal’s Lambda in addition to Cohen’s Kappa. Lambda could give another view of the ‘rater agreement’; 2. explicitly acknowledge the small number of frames (i.e., 20, l. 279) used in testing the algorithm and encourage future studies to increase it. Such a small number may generate biased Kappa and Lambda estimates and is subjected to selection risks (i.e., why this 20 out of potentially hundreds of frames? why not randomly draw from the pool of available frames?). This is a great suggestion, thank you. We have calculated the Goodman and Kruskal’s lamba and have found that the pattern is fundamentally the same. We have included the value in the methods section with the Cohen’s Kappa (line 322). We agree that future studies should add more frames where possible. We would like to acknowledge that we had a limited number of frames with diversity (i.e. frames were meant to be a representative sample of some where the individual was clearly not or was looking at the curb, as well as a representative sample of some that were more ambiguous). We have acknowledged this limitation at the end of the in the manuscript and have a sentence encouraging others to increase the number of frames in the future (lines 456-458). Lastly, I have some comments on the results section. Authors non-parametrically tested a small sample (n=10). None of the results in Section 3.1 and 3.2 reached significance (p < .05), which is not surprising given the compromised statistical power from both directions. The only significant results came from a parametric test (e.g., simple regression) in Section 3.3. To be consistent in authors’ testing approach, shouldn’t they replace the a simple regression (which basically gave estimates on Pearson r) with Spearman Rank correlation estimates? Thank you for your comment. We have changed our parametric simple regression to Spearman Rank correlation estimates (Figure 6 and lines 395-398). Reviewer #2: The study tackled an interesting topic on gaze behavior of the runners in facing the natural obstacles in terms of pre-planning vs. online planning which is important to the respective field, the statistical analyses and results were sound and the manuscript was well-written. Attachments Attachment Submitted filename: Response to Reviewers.docx https://doi.org/10.1371/journal.pone.0233158.r002
28 Apr 2020 Decision Letter - Nizam Uddin Ahamed, Editor PONE-D-20-07008R1 Gaze-Behaviors of Runners in a Natural, Urban Running Environment PLOS ONE Dear Mr. Cullen, 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 Jun 12 2020 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, Nizam Uddin Ahamed, PhD Academic Editor PLOS ONE [Note: HTML markup is below. Please do not edit.] 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 ******** 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: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: 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 #1: 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 #1: 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 #1: The revision of the manuscript reasonably address all the comments with one exception. Regarding the switch from using Pearson correlation to Spearman rank correlation, corresponding changes/edits shall be made at the section of ‘Data analysis’ (lines 339-344) and the figure illustrating the correlation between fixation number and running speed shall be updated to reflect the tested (i.e., rank) instead of original variable metrics metrics. I would endorse the acceptance of this manuscript after seeing these changes, which is necessary for a coherently presented manuscript. ****** 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: Yes: Sicong Liu [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. https://doi.org/10.1371/journal.pone.0233158.r003
Revision 2
28 Apr 2020 Author Response We want to thank the editor, Dr. Liu, and our anonymous editor for their comments. We were able to accommodate your suggestions and we think that the changes have improved the manuscript. We are grateful for the opportunity to resubmit our manuscript for publication. Response to Reviewers Reviewer #1: The revision of the manuscript reasonably address all the comments with one exception. Regarding the switch from using Pearson correlation to Spearman rank correlation, corresponding changes/edits shall be made at the section of ‘Data analysis’ (lines 339-344) and the figure illustrating the correlation between fixation number and running speed shall be updated to reflect the tested (i.e., rank) instead of original variable metrics. I would endorse the acceptance of this manuscript after seeing these changes, which is necessary for a coherently presented manuscript. Thank you for your comment, we are sorry we did not address this point fully in our last revision. We have adjusted line 339 to state “Spearman’s rank correlation” rather than “ordinary least squares regression.” We have also removed the regression line from the Spearman’s rank correlation in Figure 6. Attachments Attachment Submitted filename: Response to Reviewers_MC.docx https://doi.org/10.1371/journal.pone.0233158.r004
30 Apr 2020 Decision Letter - Nizam Uddin Ahamed, Editor Gaze-Behaviors of Runners in a Natural, Urban Running Environment PONE-D-20-07008R2 Dear Dr. Cullen, 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. Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication. Shortly after the formal acceptance letter is sent, an invoice for payment will follow. To ensure an efficient production and billing process, please log into Editorial Manager at https://www.editorialmanager.com/pone/, click the "Update My Information" link at the top of the page, and update your user information. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, you must inform our press team as soon as possible and 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. With kind regards, Nizam Uddin Ahamed, PhD Academic Editor PLOS ONE Additional Editor Comments (optional): 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 ******** 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: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: 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 #1: 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 #1: 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 #1: (No Response) ****** 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: Yes: Sicong Liu https://doi.org/10.1371/journal.pone.0233158.r005
Formally Accepted
4 May 2020 Acceptance Letter - Nizam Uddin Ahamed, Editor PONE-D-20-07008R2 Gaze-Behaviors of Runners in a Natural, Urban Running Environment Dear Dr. Cullen: I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. 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. For any other questions or concerns, please email plosone@plos.org. Thank you for submitting your work to PLOS ONE. With kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Nizam Uddin Ahamed Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0233158.r006

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