PONE-D-23-32262Sense of agency at a temporally-delayed gaze-contingent displayPLOS ONE

Dear Dr. Kim,

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. Editor comment. Two expert reviewers have commented on your manuscript, with one providing a positive review and the other a negative one. Both referees have offered useful comments that merit consideration. A recurring theme raised by both is the introduction of theoretical concepts and mechanisms, as well as the clarity of these concepts and their relationships to the operationalisation in your experiment. Reviewer 2 additionally raises several issues regarding your theorising on efferent-afferent signal discrepancy, arguing that your theoretical explanation is excessively elaborate, containing unnecessary elements that are somewhat platitudinous. In light of these comments, I advise you to address all these points in great detail. Should you feel capable of dealing with the issues raised, I recommend preparing a revised version of your manuscript accordingly.

Please submit your revised manuscript by Jan 26 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.

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• 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,

Michael B. Steinborn, PhD

Section Editor

PLOS ONE

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2. Thank you for stating in your Funding Statement: 

"Takako Yoshida was supported by a ROBOT Industrial Basic Technology Collaborative Innovation Partnership grant from the New Energy and Industrial Technology Development Organization of Japan (Grant number  JPNP20016). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

https://www.nedo.go.jp/english/activities/activities_ZZJP_100188.html

Junhui Kim was supported by the Japan Science and Technology Agency’s Support for Pioneering Initiated by the Next Generation (SPRING) Program (Grant Number JPMJSP2106).The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

https://www.jst.go.jp/jisedai/en/"

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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: No

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

Reviewer #1: Yes

Reviewer #2: No

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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: No

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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 authors investigated the effect of temporal discrepancy between action-effects and explicit measures of sense of agency using eye movements. The results showed that authorship ratings declined as the temporal discrepancy increased and that eye movement behaviour changed as a result of the discrepancy.

I thought that this study was interesting and I appreciated the several real-world examples that were given such as the remote surgery. Overall, I believe that this study should be published. At the same time, I feel that there are several loose ends that could be addressed in a revision:

1. In the introduction, could you please discuss in further detail the active rubber hand illusion and intentional binding paradigms? As it currently stands, it may be difficult for the reader to understand what those experiments involved. For intentional binding, you may also want to make clear that the Libet clock is only one of several methods of assessing intentional binding.

2. In the introduction, when discussing the comparator model, you may also want to mention the sensory attenuation phenomenon. Nathan Mifsud, for example, has looked at sensory attenuation in the context of saccade-initiated stimuli.

3. In the Methods section, you first detail the number of participants in the study, but it takes some time before you mention the number of trials then some more time before you mention the number of sessions. I suggest that you mention earlier the number of trials/sessions. Although you highlight the underpowered nature of the study at the end, stating the number of trials/sessions earlier may help to put into context the 8 participants that you end up using.

4. You asked the participants if they could remember the stimuli to evaluate if there were any effects based on sequence repetition. In principle, you could also compare the response times between the first and second sequences.

5. Under “Eye movements” (line 398), could you please specify how you arrived at the thresholds for saccade detection?

Reviewer #2: The authors claim to investigate the sense of agency using temporally delayed gaze-contingent display. Although the analyses and the results seem appropriate to some degree, unfortunately, it is difficult to know what the purpose of those analyses and results are, and therefore I cannot determine whether the manuscript as a whole is a scientifically rigorous study. The entire manuscript needs to be thoroughly reorganized and rewritten. See below for detailed comments.

1) The manuscript proceeds without first presenting a hypothesis; however, it is concluded that the hypothesis is supported. Specifically, in the Introduction, the authors describe the previous studies and state that the question of this study is to examine whether sense of agency is affected by temporal delays in eye-gaze input devices (l.125). Nevertheless, in the Discussion, they state that “the first question aimed to investigate how the efferent–afferent temporal discrepancy influences the sense of agency during continuous eye movements and stimulus updates (l.464-465). If this manuscript aims to test the hypothesis that a time delay causes a temporal discrepancy of afferent and efferent signals, which in turn reduces the sense of agency, please state that in the Introduction.

2) The manuscript does not show what psychological constructs correspond to what scales and responses, and thus what hypotheses are supported by the results. If my guess is correct, the authors seem to suggest a relationship between the discrepancy between efferent and afferent signals and the sense of agency, because two different scales yielded different result. However, the authors do not state how the variation of these two scales would suggest which of the presented constructs (e.g., efferent-afferent signal discrepancy, action-effect incongruence, non-conceptual feeling of agency, conceptual explicit conceptual judgment of agency, and arousal) are at work.

3) The fact that there is a minute (continuous) change in the sensation that participants are moving display, even though they at least know the fact that they are moving it, does not seem to support the underlying function of the efferent-afferent signal discrepancy (l.474-487). To my eyes, it appears that the time delay of the screen following their gaze was not simply long enough to make them think they were not moving the screen at all, but long enough to produce minute (continuous) changes in the loss of that sensation. If we were to follow Occam's razor, wouldn't there be no need to present the additional concepts of efferent and afferent signals? The same is true for the interpretation of eye movements. There should be no need to further add signal discrepancy concepts even though the results are already explained by the two strategies.

4) The sample size of 8 is very small compared to what is typical in the cognitive psychology field and raises concerns about the results.

5) In terms of writing, sections and paragraphs are not well organized and difficult to read.

For example, at the beginning of the Method, instead of giving an overview, the authors give the methodological details and the reasons for adopting such a procedure. In my opinion, important information scattered in the subsections included in the Method (e.g., l.224-226 and 233-235) should be summarized and described here. Note that this also leads to the placement of Figure 1 caption in a position that does not follow the PLOS guideline because it is not inserted immediately after the first place mentioned in the text.

Also, I think that readers would like to know what the questionnaire captures and how the authors expect it to generate a general replication of past results (l.157-158). In the current manuscript, only the former is revealed later (l.277-283).

Furthermore, l.284-292 are the first information that should be written in Conditions and Procedure section. I was forced to read the manuscript not knowing if the conditions were random or fixed during a certain session. Also, if the key condition is the difference in time delay, then there is no need to itemize and highlight the conditions about presence or absence of window, which only provide control condition (l.251-258).

6) Often there is no explanation of important information while there are many unimportant explanations. While it is good for reproducibility to describe procedures in as much detail as possible, too much detail can reduce the readability of the manuscript. Examples are listed below.

Why would participants be able to detect efferent-afferent temporal discrepancy by observing changes in the brightness of the boundary (l.136-137)? What this observation allows participants to do is to become more sensitive to the external stimulus feedback that is occurring in correlation with their eye movements. Unless you state that prior research has shown that such feedback exclusively reflects an afferent-efferent discrepancy, you are making a leap of logic.

Some sentences (l.180 to 181 and 191) do not seem necessary. It should be sufficient to simply state that the test was performed in a dimly lit room so that key press responses are possible.

What is the meaning of l.210-213?

What is the meaning of (B) in l.246 and (C) in l.248?

I don't understand what l.272-273 are explaining, and it would be better to explain first what the objective of the playback trials is.

If the screen refresh rate is 144 Hz for 2000 Hz eye movement measurements, it should be necessary to approximate the eye movements in time, but the method is not described. Note that eye movements are very fast, and the temporal resolution is critical.

Why does pop-out occur in the letter category (l.208)?　According to Triesman's feature integration theory, pop-outs occur on screens where simple features such as color and shape are uniquely different.

7) I don't particularly understand what the purpose of the first analysis (l.301-) was. What is the purpose of showing the task difficulty? Furthermore, I can't say with confidence that reaction time reflects difficulty because participants are asked for a two-step response and given no instruction to respond as quickly as possible (l.153-154).

9) In l.358-362, the authors state that the lack of statistical significance is due to the small sample size, but immediately afterwards they conclude that there is no difference because there is no significant difference, which is contradictory. Furthermore, the absence of a statistically significant difference does not directly indicate the absence of a difference.

I hope that these comments will help you to improve future manuscripts.. Thank you for the chance to review your research.

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Reviewer #1: No

Reviewer #2: No

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PONE-D-23-32262R1Sense of agency at a temporally-delayed gaze-contingent displayPLOS ONE

Dear Dr. Kim,

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 submit your revised manuscript by Apr 27 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,

Michael B. Steinborn, PhD

Section Editor

PLOS ONE

Additional Editor Comments:

I have now received feedback from the two initial reviewers (R1 was positive, while R2 was initially negative), and I further sought additional opinions from another expert (R3). R1 now finds the manuscript ready for publication, while R2 has moderated his stance a bit but still has some remaining issues that need consideration in another revision. It is also noteworthy that R3’s feedback aligns well with the original points by R1 and R2, particularly with regard to the need to clarify theoretical arguments for (model-based) predictions and, accordingly, to improve the discussion. These comments should be addressed to clarify issues previously highlighted by the other reviewers. I recommend preparing a revised submission, accompanied by a detailed letter that addresses each comment point by point. Good luck with the revision.

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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)

Reviewer #3: (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: Partly

Reviewer #3: Partly

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

Reviewer #1: (No Response)

Reviewer #2: Yes

Reviewer #3: 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

Reviewer #3: 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

Reviewer #3: 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: (No Response)

Reviewer #2: I thank the authors for their efforts in revising the manuscript. The revision significantly improved the logic of the manuscript; I mean, my previous critical concern has been addressed. I now understand the authors' primary argument. The authors investigated the sense of agency in terms of the action-feedback discrepancy using the gaze-contingent display. This study may have a theoretical ground of a comparator model, but it does not directly and empirically address this model in detail. Despite this theoretical uncertainty, this study provided important findings because of the real technological situation of widespread gaze interfaces, possibly with temporal delay.

Nevertheless, I suggest further refinement of the paper. The revised manuscript separately clarified what was directly empirically addressed and what was speculative but theoretically probable. If this holds, expanding theoretical considerations in Discussion is not precluded but rather encouraged.

Moreover, I still recommend a reader-friendly narrative for several descriptions to follow the sequence of providing a more general description followed by a detailed description. It is essential to try to avoid misleading the general reader. Indeed, I gave negative feedback on the first peer review but have now altered it by looking at the current improved descriptions. See below for detailed comments.

1) It would be fruitful to have a detailed speculative discussion about the theory as far as the authors define it as speculation. I encourage the authors to provide an exhaustive, if not integrated, discussion of the following results: the authorship rating significantly decreased during the temporal discrepancy between 200-300 ms, the mode of fixation duration (one mode reflecting wait-and-read) progressively shifted between 0-500 ms, and only one strategy (pre-registering) was adopted above 500 ms. I believe that a comprehensive discussion of these results will enhance the value of the results and eliminate possible misunderstandings.

First, the authors devote much of the paper to describing the two modes of fixation duration between 200 and 500 ms temporal discrepancies. However, in the context of this study, the important point seems to be the degree to which one mode reflecting the wait-and-read strategy gradually shifted between the discrepancy of 0 to 500 ms. This is because another mode reflecting pre-registering may only reflect a task-specific search strategy that primarily occurs in a discrepancy range of 1,000 to 4,000 ms, which is clearly beyond the time range that can be ascertained only by the comparison of afferent and efferent signals (this led to my earlier objection to the suggestion of a comparator model based on the results). Is it possible to, for example, statistically reveal that the mode reflecting the wait-and-read strategy did not shift much in the discrepancy range from 0 to 100 ms, but suddenly shifted from 200 to 300 ms? That is, if you want to leave a claim about the comparator model, you may extract the trials in which the read-and-wait strategy was employed to see if such a result can be obtained (this is not mandatory, since it may require a great deal of effort to manually browse all the data). If you observe such a fact, it may be possible to argue, for example, that the sense of agency or the comparison of afferent and efferent signals (critically changing at 200-300 ms) is behind the behavioral changes in gazing found here. Whether or not an analysis is performed, we recommend at least explaining these details in the discussion.　

On the other hand, is the degree of sense of agency relevant to why wait-and-read strategy is no longer taken at the temporal discrepancy of 1,000 ms or more? It is not clear whether you interpret this phenomenon as having something to do with authorship rating. You seem to be explaining it in the different viewpoint from authorship rating, such as referring to the limitations of memory (lines 570-572 in clean copy); however, at the same time, you are basing your interpretation on prior research on sense of agency (lines 573-576).

Elaborating on these aspects may facilitate the interpretation and exclude possible misunderstandings. If these interpretations are unclear, as I did previously, it could be read as if the one mode (pre-registering strategy) in the range of 1,000-4,000 ms discrepancy, different from the two modes in other range, implies the function of the sense of agency or comparator model. As I pointed out previously, adopting the strategy (i.e., pre-registering) for a particular task in response to such a cognitively detectable, explicit temporal discrepancy can be explained without the concept of a sense of agency and, particularly, the comparator model. Conversely, discussion that emphasizes the shift of one mode reflecting wait-and-read strategy may provide a theoretical contribution to the sense of agency and the comparator model.

2) The introduction explaining the purpose of this study, although noticeably improved, still seems to need to flow better and aid the reader's understanding. Could the sentences in lines 83-100 be made to connect point-by-point with the hypotheses, if possible, while emphasizing what is directly relevant to your experimental design (i.e., the contents described in lines 124-136)?　

3) In the method description, I recommend that you first describe your intent in your study and then supplement your reasons.

As for lines 202-245, my previous suggestion was to summarize and describe the important procedures here, not to describe all the details first. I suggest that only the important details be described here. Nevertheless, I agree that the experimental procedure is rather complex and that it will not be conveyed to the reader unless the procedural details are described to some extent here.

In lines 236-243, I think, the statement should be in the order that you wanted to use peripheral blurring for several reasons, and therefore, this required reducing the problem of saccade amplitude effects, resulting in the current methodology.

Minor (formal) comments

a) Generally, in a reply letter to review comments, the authors write the reply after describing the reviewer's original comments. In some systems, the reviewers cannot see their previous comments and may have inconvenience.

b) In the results, some ambiguity remains in the description. Figures 3-5 illustrate the performance in the playback condition. In this condition, is the participant performing a visual search or not? When I saw the word "playback" alone, I imagined that there was no search. It is recommended to explain it.

c) Is it common or in accordance with PLOS guidelines to insert a limitation section after the conclusion?　Personally, I don't see these sequences very often (I often see the limitation before the conclusion).

Reviewer #3: The authors investigated the sense of agency for eye movements and its association with temporal delays. They administered a gaze contingent window and delayed its movement by 0-4000ms. They found that temporal delay lead to decreased sense of agency, which is well in line with previous research. I find the paper interesting and appreciated the connections to the applied research field of HCI. However, I think that the manuscript should be restructured in some crucial sections to increase clarity. Further, I find the discussion lacking and somewhat missing the point of sense of agency for eye movements, as the authors tend to emphasize other aspects of eye movements and action control, rather than agency. I think the manuscript would greatly benefit by a thorough revision of the discussion. See below for detailed comments:

1. The title and introduction of your manuscript suggest a primary focus on the sense of agency in relation to eye movements. This sets up an expectation for the reader that the core findings and discussions will revolve significantly around this theme. However, upon reviewing the discussion section, I've noticed that the main results, specifically the agency ratings affected by the manipulations of delay and gaze window, are addressed only comparably briefly (l. 493-537 and l.612-622). Instead, there appears to be a substantial emphasis on what seems to be exploratory findings related to the suspected action strategies of the subjects (l. 537-611).

These exploratory findings, while intriguing, were not well grounded in the theoretical framework laid out in the initial sections of your paper. Given their speculative nature and the relatively small sample size of your study, these findings require cautious interpretation. Yet, they seem to be presented with considerable emphasis, overshadowing the more critical discussions surrounding the sense of agency, which is purportedly the central theme of your study. Furthermore, these strategies are not discussed in relation to the sense of agency but stand somewhat on their own.

I recommend revising the discussion section to rectify this imbalance. A more thorough exploration of the sense of agency, particularly how it is influenced by your experimental manipulations and how this fits to aspects from your introduction (such as the comparator model, etc.), would align better with the expectations set by your paper's title and introduction. While the exploratory findings regarding action strategies can still be included, they should be contextualized appropriately within the broader narrative of your study, and their speculative nature should be clearly articulated. This approach would not only strengthen the coherence of your manuscript but also ensure that the primary focus remains on the sense of agency, as initially suggested.

2. In your manuscript, you mention at several junctures (notably lines 101-107 and 146-148) that your work is the first to systematically look into the association between sense of agency for eye movements and temporal delays. Further, you report a notable scarcity of research connecting eye movements and sense of agency, referencing only the study by Grgič et al. While I agree that the sense of agency for the oculomotor action domain may not be as extensively explored as others, such as in the manual action domain, I'd like to point out that there exists a broader range of studies than suggested. In particular, there have been investigations into the sense of agency in gaze-contingent paradigms, including systematic analyses of temporal discrepancies or delays. Here are some references that may enrich your discussion:

• https://doi.org/10.1007/s12193-018-0286-y

• https://doi.org/10.1016/j.actpsy.2023.104121

• https://doi.org/10.3758/s13428-019-01299-x

I recommend refining your statements about the uniqueness of your research to reflect these contributions. It would also strengthen your paper to integrate these studies into your introduction and consider them when discussing your results.

For full transparency, I want to clarify that I am one of the co-authors of the paper titled "Eye did this! Sense of agency in eye movements". My suggestion to include this and the other studies is not meant to enforce citation of my own work. Instead, I believe they offer relevant insights that could enhance the depth and context of your manuscript.

3. In your manuscript, I noticed that the exact task assigned to participants was not clearly detailed, specifically regarding the concrete instructions they were given. Understanding the precise instructions is crucial for interpreting the participants' responses and the overall outcomes of your study. For instance, in "Questionnaire 1," participants were asked to rate whether the window shift could have been caused by some "other" person or entity. This prompts me to wonder about the context in which they might consider someone else as the author of the action.

In the study by Farrer et al., which you cited, it is clear that participants were informed that the movement of the virtual hand could also be caused by the experimenter. This setup provides a logical basis for participants to potentially attribute the movement to another person. However, it remains unclear whether a similar context was established in your study. Did your participants receive instructions that led them to believe that the movements of the gaze window they observed could be externally induced, perhaps by the experimenter or another entity? Clarifying this aspect would greatly enhance the understanding of why participants might attribute actions to external sources, aligning or contrasting with the precedent set by Farrer et al. Please provide detailed information on the instructions given to participants to help clarify this issue. The results should also be discussed with this in mind.

4. The Methods section of your manuscript appears to lack clear organization, which could hinder the reader's understanding of your study's design and execution. To improve clarity and coherence, I recommend restructuring this section into the following subheadings:

1. Participants

2. Apparatus and Stimuli

3. Procedure and Task: I suggest consolidating the content from lines 202-245 and 331-341 under this heading. Within this subsection, I would suggest beginning by explaining the task that participants were required to perform. Then I would follow this with a description of the different visibility conditions implemented in the study. Next, I would outline the agency questions posed to participants, ensuring to clarify the context and purpose of each. Finally, I would detail the block structure of the experiments, including how tasks and conditions were ordered and any variations between different conditions.

Furthermore, I note a lack of a dedicated section for statistical analysis. Such a section is crucial for understanding how the data were treated and interpreted. Please create a separate section for Statistical Analysis, incorporating the relevant details currently found in lines 366-371, 390-395, and 423-425. In this new section, describe the analysis methods used, the factors considered, alpha-levels set for significance, any post-hoc tests applied, etc.

5. I think that your manuscript would also benefit from some clarifications:

• You refer to misattribution of agency in several sections, e.g., “First, participants will not misattribute with temporal delays in eye-gaze HCI, as seen in the previous findings [22].” (l.126-127) or in l. 495. This phrasing is somewhat difficult to comprehend, please clarify what is meant by “misattribute”

• In a similar manner, you write “Moreover, it has been proposed that the two choices of 'self' and 'other' do not fully cover scenarios where participants perceive their actions as contributing to an outcome, but not completely or directly.” (l. 155 - 157). Please clarify what is meant by “perceiving their actions as contributing to an outcome, but not completely or directly”. You could also refer to this explanation when you discuss the task instruction (see reviewer comment #3)

• I struggle to fully understand the two strategies (wait-and-read vs. pre-registering) in section l. 538-552. Could you please further clarify these strategies and how they differed from each other?

Minor Concerns:

6. You state, that sense of agency “cannot be adequately represented by a continuous degree rating.” (l. 155). I think that the reasoning behind this statement should be better explained and carefully debated. For me, it makes sense that the adapted Farrer questionnaire still leaves an option open to differentiate between “self”, “delayed”, and “other”. However, you should briefly explain what you consider to be the specific problems (and benefits?) of a continuous scale in contrast to the Farrer-questionnaire. A more differentiated consideration seems particularly useful to me here because you yourselves use a continuous scale to measure sense of agency in the later text (l.164-174).

7. I would encourage you to give some form of sample size justification even if only acknowledging the absence of any justification. A good guide for this is provided by the paper by Lakens, 2021: https://www.semanticscholar.org/paper/Sample-Size-Justification-Lakens/c591254d1746341feae3eb6d217c970ff4bc9a87

8. The section l. 452-456 should be moved to the Apparatus section.

9. In your Results section, you refer to your questionnaires as “First Questionnaire” and “Second Questionnaire”. I would prefer a more meaningful naming, for example “categorical” vs. “continuous” questionnaire, etc.

10. I found the text in l. 380 – 384 to be redundant to the figure description in l. 386-388. I think that the figure description is sufficient and the text in l. 380-384 could be deleted or shortened.

11. You give information about the mean differences between conditions for your post-hoc tests in some sections (e.g., l. 358-360) but in other sections you just report p-values without condition means (l. 363-365, l. 442-444). Please also report the means in these sections so that the reader can understand in which direction the effect is pointed and how large the effect might be.

12. Last, I would encourage you to report some measure of effect size for your ANOVAs and mixed models. This might be especially helpful in regard to the small sample size. You state in the Limitations section that your study might have been underpowered, but this can only be determined if the effect sizes are estimated.

I want to thank the authors and the editor for giving me the opportunity to review this paper. I hope that my feedback is helpful.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: Yes: Julian Gutzeit

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PONE-D-23-32262R2Sense of agency at a temporally-delayed gaze-contingent displayPLOS ONE

Dear Dr. Kim,

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. Editor comments. I have now received all reviews and, based on their opinions, a decision can be made. All reviewers were constructive and engaged in an excellent dialectical discourse, which is outstanding and aligns with the scientific ideal we aspire to. At present, all three reviewers are generally satisfied and find the manuscript in proper shape, although they have some remaining comments. R3, however, has additional issues that must be resolved before publication, but these will not take much time to address in the final preparation of the manuscript. We are now close to the final stage, and I ask you to revise the manuscript in a final revision, which I believe will likely be the last round. Please provide a point-by-point response to the comments.

Please submit your revised manuscript by Sep 07 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.

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Michael B. Steinborn, PhD

Section Editor

PLOS ONE

Journal Requirements:

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:

In the following, I provide comments on various issues I find relevant for the revision. Additionally, I will address and discuss comments from all reviewers to clarify their potential implications and how to handle them in the final manuscript revision. I want to emphasise that my comments are intended to improve the manuscript, not to criticise your work. I do not expect you to agree with all of my points; in other words, I do not claim that my opinion is always correct. I see myself more as a moderator, facilitating the interaction between authors and reviewers to enhance the final quality of the manuscript. I have no claims to absolute truth or insistence on my views, just to clarify.

(-1-) models of agency and temporal delay

The authors argue that participants did not misattribute authorship with temporal delays, which in their interpretation, strongly supports the hypothesis that such delays are not strong enough to cause misattribution. Based on the comments from R1, R2, and R3, I suggest presenting a more elaborate interpretation in the final revision of the manuscript. Here are some ideas, mainly derived from the reviewers' comments: Why and when do we perceive a sense of agency during our actions? And when are these perceptions strong enough to change how we view an action or our role in it? Let me explain, bearing in mind my perspective as a layman reader of your manuscript. Whether we perceive a sense of agency during an ongoing action sequence or a performed action depends on the temporal proximity between our (a) intention formation, (b) action initiation, and (c) the consequence of the action (i.e., the outcome of the action) (supporting refs: doi:10.1007/s00221-020-05861-4). This is clear in everyday situations. For example, when an individual presses a light switch, they observe their finger move, feel the switch haptic feedback, and see the light turn on almost instantaneously. This immediate temporal coupling between the action and the sensory feedback leads us to "know" we are the cause and intended agents of that action.

We can distinguish between two categorical kinds of agency: one refers to the ongoing process (perceptual regulation), and the other refers to the outcome of the intended action (outcome control). Both contribute to the feeling of "authorship" of the action, depending on the situational model. This means we can perceive something as "caused by us" even if it is not immediately contingent, because we often rely on internal representations of expected temporal delays. For instance, when pressing a button on a coffee machine, there is a "known" delay of about 1 minute before the coffee is dispensed. Despite this delay, individuals still perceive themselves as the "author" of the action, as their internal model includes the temporal parameters of the situation. This internal representation allows for a sense of agency even when the outcome is not immediate, as long as the delay is within the expected timeframe of the individual mental model. In the context of the current study, the temporal delays introduced were likely ot sufficient to disrupt the internal models or the immediate temporal contingencies necessary for the sense of agency, yet alternatively, the implanted mental model (delivered by the paradigm) was not clear enough. Why is this the case? It is difficult to say definitively, as I am not an expert, but fundamentally, participants retained their sense of authorship despite the delays, likely because these delays were within the bounds of their internal representations of how long actions and outcomes should be linked. This highlights an important aspect that needs further discussion: the concept of "situational model ambiguity". Lewin (1943) referred to this as "strong vs. weak" model situations. This concept should be elaborated upon in the discussion section to provide a deeper understanding of the findings.

(-2-) wait-and-read vs. pre-registering

Two main strategies were identified: "wait-and-read" and "pre-registering," demonstrating how participants adapted to varying delays. Based on the arguments of R2 and R3, it seems that we are observing aspects of perceptual control (which the authors conceptualise more as preregistered online control) and model-based control (outcome control). I suggest elaborating more on the critical experimental factors that comprise the design and collectively conceptualise the representable model situation, rather than focusing on technical details.

R2 argues that although spatial attention is acknowledged, it is only briefly mentioned by name. R2 (but also R3 in some sense) ague that the discussion should emphasise this more by elaborating more deeply on temporal attention, as it aligns more closely with the present main hypothesis. For example, to make that point clear, R2 notes that oculomotor events, such as pupil diameter regulation and gaze position stability, are closely linked to the timing of target appearance, and this can be discussed in two ways: first, it concerns the specific model situation being addressed. The authors discuss the impact of delays in contingent displays and have implications for designing delay-tolerant gaze-contingent systems, indicating that they already have specific model situations in mind. However, these are not fully articulated. Second, there is a fundamental aspect related to the basic structural conditions of temporal preparation. This aspect should be prioritised and more thoroughly examined in the discussion to provide a comprehensive understanding of the findings. Suggested references supporting these arguments further are here:

Cao, L. et al. (2020). Action force modulates action binding: Evidence for a multisensory-integration explanation. Experimental Brain Research. doi:10.1007/s00221-020-05861-4

Logan, G. D., & Crump, M. J. C. (2010). Cognitive illusions of authorship reveal hierarchical error detection in skilled typists. Science, 330(6004), 683-686. doi:10.1126/science.1190483

Powers, W. T. (1973). Feedback: beyond behaviorism. Science, 179(4071), 351-356. doi:10.1126/science.179.4071.351

Yamashita, J. et al. (2022). Pupillary fluctuation amplitude preceding target presentation is linked to the variable foreperiod effect on reaction time in Psychomotor Vigilance Tasks. Plos One, 17(10), e0276205. doi:10.1371/journal.pone.0276205

(-3-) novelty

Both R2 and R3 express concerns about the authors presenting their findings as absolutely novel or unprecedented, requesting corrections. R3 questions whether the results confirm previous knowledge or offer novel insights capable of reshaping the theoretical landscape, arguing that it is unclear what new contributions this study makes. Meanwhile, R2 emphasizes the importance of understanding the mechanics underlying perceptual agency and authorship. While I fully agree with these points, I want to defend the authors by clarifying that the aim of cognitive psychological research should be to systematically delineate mechanisms, such as how people represent actions and their consequences, rather than constantly aiming to surprise. Otherwise, we risk falling into the trap of sensationalist reporting that prioritises eye-catching headlines over factual accuracy and integrity. "Novelty" should not be misconstrued as "discovery," especially in a field prone to false-positive results. Therefore, a lack of novelty is not problematic simply because an effect or correlation has been reported previously, as it is more crucial, at least in my view, to recognise that many findings in a field are often inconsistent, and demonstrating systematic experimentation is therefore valuable. I suggest the authors therefore to elaborate and outline (at the end of the discussion) how an improved (modified or optimal) experimental approach would look like and how this can be implemented in future research on this subject. 

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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: (No Response)

Reviewer #3: 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: Partly

Reviewer #3: Yes

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

Reviewer #2: Yes

Reviewer #3: 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 #2: Yes

Reviewer #3: 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 #2: Yes

Reviewer #3: 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 #2: Most of the comments previously noted have been addressed appropriately. One final point still needs to be addressed, but overall, I believe the manuscript is now in an acceptable condition. We thank the authors for their efforts to improve the manuscript.

In lines 889-919 (clean copy), I think the authors should discuss oculomotor stability in relation to temporal attention. Although I do not deny the involvement of spatial attention, I think a discussion related to temporal attention, which is more relevant to the main hypothesis of the manuscript, is warranted. It has been noted that when a target appears at a certain time, various oculomotor events tend to stabilize as it approaches the expected time of target presentation, perhaps to get clearer image input at that time. For example, the pupil diameter, which plays a role in regulating the intensity of the image entering the eye, is stable at the time when a potential target is likely to appear (https://doi.org/10.1371/journal.pone.0276205). Also, changes in pupil diameter may lead to fine-scale variations in gaze position as measured by the eye tracker (https://doi.org/10.1371/journal.pone.0111197). It has also been reported that the gaze position becomes stable at the time when the target is about to appear (https://doi.org/10.1016/j.neuroimage.2018.09.026; https://doi.org/10.1167/jov.23.14.1). I recommend primarily discussing these previously found phenomena in relation to the correlation between the display lag and fine-scale variation in gaze position.

Minor remarks:

1) Recently, an article has been published by the same author dealing with a similar topic (https://doi.org/10.3389/fpsyg.2024.1364076). It does not seem to deal with the exact same hypothesis, and there may not be any problem in terms of publication ethics. Nonetheless, it may be safer to cite the article. Also, please make sure that you are not using the same text or images.

2) Because the analysis in the manuscript is voluminous, I suggest giving a brief summary of the specific hypotheses at the end of the introduction or at the beginning of the methods (if it doesn't interfere with the opinions of other reviewers). Here, you may use a shortened version of sentences in lines 685-691 as a summary.

3) When citing reference [35] in line 125, the full name is listed for some reason. Please check the citation format.

Reviewer #3: Thank you for your detailed response to my comments on the manuscript titled “Sense of agency at a temporally-delayed gaze-contingent display”. I appreciate the efforts made to address the concerns and suggestions I raised in my initial review. I think that the quality of the manuscript has increased substantially. The structure is very clear and it is easy to follow the reasoning of the authors. Moreover, the discussion is now much better balanced and focused on sense of agency. I only have some minor comments:

1) I appreciate the new, differentiated contextualization of your study in light of previous research examining the sense of agency for eye movements and temporal delay, avoiding the claim of being the first to investigate this association. In the revised version, the novelty of your approach—namely the continuous eye movements compared to single saccades in previous research—is much better highlighted. However, the phrasing in the abstract, “This study is the first attempt to systematically examine the relation between temporal discrepancy and eye movements” (lines 28-29), is still somewhat misleading or a bold claim. I would appreciate it if you could tone down this statement and briefly describe the uniqueness of your approach more clearly in the abstract, as you did in the manuscript.

2) It is unclear how the 60 sessions were distributed over the days. You wrote: “Each participant required over two months to complete 60 sessions, making it challenging to recruit additional participants” (lines 260-262). Does this mean that each session was held on a separate day, or were multiple sessions conducted in a single day? Please clarify this briefly in the Task and Procedure Section.

3) Typo in l. 474: “200-30 ms”, should be “200-300 ms”, right?

4) In Figure 3, it is difficult to distinguish between the three categories (self, delayed, and other). The plot might be easier to interpret if the positions of the data points were dodged. This issue is particularly pronounced for the points in the playback condition. However, dodging the points might lead to clutter and reduce readability. I encourage the authors to try a dodged version to determine if it improves or worsens the plot's readability. The same suggestion applies to Figures 4 and 5.

I look forward to seeing the final version of the manuscript.

Thank you for your hard work and attention to detail!

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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

Reviewer #3: Yes: Julian Gutzeit

**********

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Sense of agency at a temporally-delayed gaze-contingent display

PONE-D-23-32262R3

Dear Dr. Kim,

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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Michael B. Steinborn, PhD

Section Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: