Quantitatively Measuring Developmental Characteristics in the Use of Deictic Verbs for Japanese-Speaking Children: A Pilot Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1) This paper is a little too dense. In particular, a more detailed discussion of data collection is necessary. It would help to have a few illustrations of all the steps taken with examples of what was shown, said, measured, etc. It is similar to the components discussed in 2.3, but SPECIFIC examples would give the reader a better idea of what went on. Also, it is critical to provide Japanese sentences for the key go/come sentences with glosses and translations. Sure, the reader can perhaps get an idea of what was done by inspecting the materials in the paper, going back to Asaoka et al. 2021, etc. But A little illustration would make it much easier to follow the paper, especially for non-specialist readers like myself.

2) This is related to 1) but probably more important. How do the results presented in section 3 lead to what is in section 4, especially its main suggestion (i.e., appropriate verbal responses and body movements based on actual directions appear only in the acquisition stage of “come/go” and subsequently disappear.) Please spell out the connection.

Author Response

We sincerely appreciate your thorough and insightful review. Your comments on improving clarity were invaluable. We have addressed your suggestions by adding detailed illustrations, expanding explanations, and clarifying the connection between our results and conclusions.

Comment 1:
This paper is a little too dense. In particular, a more detailed discussion of data collection is necessary. It would help to have a few illustrations of all the steps taken with examples of what was shown, said, measured, etc. It is similar to the components discussed in 2.3, but SPECIFIC examples would give the reader a better idea of what went on. Also, it is critical to provide Japanese sentences for the key go/come sentences with glosses and translations. Sure, the reader can perhaps get an idea of what was done by inspecting the materials in the paper, going back to Asaoka et al. 2021, etc. But A little illustration would make it much easier to follow the paper, especially for non-specialist readers like myself.

Response 1:
We have added Figure 3 (page 9), which is a comprehensive flowchart detailing the procedure for each trial. This flowchart provides specific examples of the actions taken by both the researcher and the participant, including what was shown, said, and measured. We have also expanded Section 2.3 (line 227) to include more specific examples and clearer descriptions of each step in the process. Furthermore, we have added Table A1 (pages 17-18), which provides Japanese sentences containing “go/come” verbs, along with their romanized versions, word-by-word glosses, and natural English translations.

Comment 2:
This is related to 1) but probably more important. How do the results presented in section 3 lead to what is in section 4, especially its main suggestion (i.e., appropriate verbal responses and body movements based on actual directions appear only in the acquisition stage of “come/go” and subsequently disappear.) Please spell out the connection.

Response 2:
lines 360-71. We appreciate the opportunity to clarify the connection between our results and our interpretation. Upon careful reconsideration of our findings, we have determined that our initial interpretation was too strong given the cross-sectional nature of our study. We have revised our discussion to more accurately reflect our results.

Reviewer 2 Report

Comments and Suggestions for Authors

Manuscript ID: languages-3108705

Title: Quantitatively Measuring Developmental Characteristics in the Use of Deictic Verbs for Japanese-speaking Children: A Pilot Study

A brief summary of the study and overall comments

 

The study makes a unique contribution to the understanding of the acquisition of deictic verbs in TD Japanese-speaking 6-7 year olds, through investigating the relationship between the utterances of come/go and the body movements that accompany the speech.  The relationship between responses to questions that require the use of deictic verbs (kuru/iku) and the body movement that occurred together with each response was analyzed. Based on the results the author(s) argue(s) for a temporary stage in which the body movement is compatible with the speech but such alignment disappears at later stages.  I believe he study provides important insights into the complex relationship between the use of deictic verbs and deictic gestures by quantitatively measuring the body movements using innovative approach/method and by presenting an in-depth discussion based on the findings. Below are comments/questions for the further improvement of the article.

Comments for each section

1.     Introduction

I believe the background information for the current study can be presented more in detail so that the readers can gain a more substantial understanding of the theoretical framework and the relevant previous studies, which will help them understand the significance of the current study.  More specifically,

-       A more extensive discussion on the concept and the mechanism of “deictic shifting” will benefit the readers.

-       The nature of ellipsis and the nature of deictic verbs of the Japanese language, as well as the relationship between the two should also be addressed and discussed more in detail to give a more comprehensive background to the readers. 

-    In particular, an illustration of the crosslinguistic differences in the deictic expressions between Japanese and English is indispensable to accurately understand the data presented in this study.

-       Furthermore, a more comprehensive discussion of the previous studies on the acquisition of deictic verbs in Japanese child language among typically developing (TD) children, not limited to Masataka (1998), needs to be presented, unless Masataka (1998) is the only available previous research on this topic.

Line-by-line comments

1)    lines 30-31

“…In this study, we addressed the use of “come/go” in the Japanese language, and the key characteristic is the omission of subjects such as “I/you” in daily conversation.”

➡I think this sentence needs clarification. “the key characteristic” of what?  More importantly, why is the omission of subjects the “key” characteristics (of the deictic verbs, I assume)?

2)    lines 33-40

“..Additionally, as an example of deictic shifting in Japanese conversations, Kai invites Mio to the movies, “It’s happening! The Doraemon movie just started streaming! Will you come to my house today to watch it?” Mio first perceives the movement from Kai’s  perspective, for example, “From Kai’s viewpoint, Mio comes to my house.” Subsequently, Mio shifts her perspective to “From my viewpoint, I go to Kai’s house” and responds, “Yeah, I want to go today!” or “Sorry, I can’t go today because I have plans to hang out with Riko.”

➡Can this example be presented as an excerpt of a conversational discourse (example below), and add explanations regarding deictic shifting after that? I think it will make it easier to read (easier to distinguish between the actual utterance and the explanation about the speaker’s viewpoints).

Kai: It’s happening! The Doraemon movie just started streaming! Will you come to my house today to watch it?

Mio: Yeah, I want to go today!/ Sorry, I can’t go today because I have plans to hang out with Riko.

3)    line 35

“It’s happening! The Doraemon movie just started streaming!...”

➡I am not sure what “It’s happening!” means in this context. I would suggest that the author(s) delete this part.  This may be minor but I wonder if “Doraemon” is clear to the readers who are not familiar with the Japanese culture. This can also be deleted.

4)    line 40.

“Hereinafter, “come/go” is used based on the Japanese forms.”

➡What do you mean?  Please add more explanation.  What are “Japanese forms”?

5)    lines 42-3

“The researcher asked “come/go” questions to the participant…”

➡Is it possible to add a few examples of the questions used in the study?

6)    lines 48-49

“…Consequently, the following three acquisition sequences were suggested:…”

➡I wonder what the author(s) mean by “acquisition sequence”. If Masataka (1998) is a cross-sectional study, how can an acquisition sequence be suggested based on the findings?  I think the rationale of this interpretation/argument needs to be presented.

7)    lines 91-6

“..We predicted that TD children would move their bodies slightly backward when uttering “come” and forward when uttering “go.” Furthermore, we predicted that this tendency would be stronger in responses to the types of questions that require deictic shifting (e.g., “Will you come to my house to play after school?”) than in types of questions where it is not required (e.g., “Will you go to the library with me?”).”

➡It may be better to mention the rationales for each prediction.

2.     Materials and Methods

Line-by-line comments

1)    lines 131-3

“..The first author, serving as the researcher, took on the role of either a child actor or the father of the participating child.”

➡Could you clarify what you mean here?  Why did the researcher have to take the role of a child actor or the father of the child?

2)    lines 162-4

“..In total, 20 trials were conducted, with each trial consisting of sitting in type-specific positional relations, the cues by clapperboard, the narrations, the researcher’s phrases, and the participant’s phrases, in that order.”

➡Could you clarify what you mean here?  

3.     Results

Overall, the presentation of the results seems to lack details. I suggest that each analysis be reported more elaborately.

Line-by-line comments

1)    line 230

“The participant and overall results are shown in Tables 3 and 4, respectively.”

➡Please provide more specific explanations of what is being described in each table.

4.     Discussion

Line-by-line comments

1)    lines 264-6

“..One of the most significant findings of this study was the suggestion that appropriate verbal responses and body movements based on actual directions appear only in the acquisition stage of “come/go” and subsequently disappear.”

➡I wonder which data supports this claim, and where this “suggestion” is mentioned.  I think the readers will benefit from more detailed explanation on how the results would lead to this argument.

2)    line 273

“…Based on these results, we discussed factors related to the acquisition of deictic verbs regarding spatial perspective-taking”

➡Do you mean we “discuss” in the following paragraphs?

3) line 333

“…should include not only 6-year-olds but also younger and older children…”

➡6 to 7 year-olds?

Comments on the Quality of English Language

I think the text needs further English editing.

Author Response

We greatly appreciate your detailed and constructive review of our manuscript. Your insightful comments have significantly contributed to improving the clarity and depth of our paper, particularly in the Introduction section. Additionally, your line-by-line comments were especially helpful in refining specific aspects of our methodology, results presentation, and discussion.

1. Introduction

I believe the background information for the current study can be presented more in detail so that the readers can gain a more substantial understanding of the theoretical framework and the relevant previous studies, which will help them understand the significance of the current study. More specifically,

Comment 1:
A more extensive discussion on the concept and the mechanism of “deictic shifting” will benefit the readers.

Response 1:
lines 33-46. We have expanded our introduction to include a more detailed explanation of the concept and mechanism of deictic shifting. This expanded discussion draws on the work of Zubin and Hewitt (1995) and includes specific examples to illustrate how deictic shifting operates in Japanese language-use.

Comment 2:
The nature of ellipsis and the nature of deictic verbs of the Japanese language, as well as the relationship between the two should also be addressed and discussed more in detail to give a more comprehensive background to the readers. In particular, an illustration of the crosslinguistic differences in the deictic expressions between Japanese and English is indispensable to accurately understand the data presented in this study.

Response 2:
lines 51-86. We have expanded our explanation on Japanese ellipsis and deictic verbs “come/go.” We have also included a comprehensive comparison of deictic verbs in Japanese and English, providing examples and explaining differences in subject explicitness and interpretation.

Comment 3:
Furthermore, a more comprehensive discussion of the previous studies on the acquisition of deictic verbs in Japanese child language among typically developing (TD) children, not limited to Masataka (1998), needs to be presented, unless Masataka (1998) is the only available previous research on this topic.

Response 3:
We did not add additional literature. To the best of our knowledge, Masataka (1998) is the only study that has investigated the relationship between language production and body movements in Japanese-speaking children.

Line-by-line comments

Comment 4:
lines 30-1. “…In this study, we addressed the use of “come/go” in the Japanese language, and the key characteristic is the omission of subjects such as “I/you” in daily conversation.”
→I think this sentence needs clarification. “the key characteristic” of what? More importantly, why is the omission of subjects the “key” characteristics (of the deictic verbs, I assume)?

Response 4:
line 63. We have clarified that we are referring to the key characteristic of deictic verbs.

Comment 5:
lines 33-40. “..Additionally, as an example of deictic shifting in Japanese conversations, Kai invites Mio to the movies, “It’s happening! The Doraemon movie just started streaming! Will you come to my house today to watch it?” Mio first perceives the movement from Kai’s perspective, for example, “From Kai’s viewpoint, Mio comes to my house.” Subsequently, Mio shifts her perspective to “From my viewpoint, I go to Kai’s house” and responds, “Yeah, I want to go today!” or “Sorry, I can’t go today because I have plans to hang out with Riko.”
→Can this example be presented as an excerpt of a conversational discourse (example below), and add explanations regarding deictic shifting after that? I think it will make it easier to read (easier to distinguish between the actual utterance and the explanation about the speaker’s viewpoints).

Kai: It’s happening! The Doraemon movie just started streaming! Will you come to my house today to watch it?
Mio: Yeah, I want to go today!/ Sorry, I can’t go today because I have plans to hang out with Riko.

Response 5:
lines 51-61. As you have suggested, we have presented this example as the conversational excerpt. Moreover, we have placed the explanation regarding deictic shifting immediately before the excerpt to maintain consistency with other examples in our study.

Comment 6:
line 35. “It’s happening! The Doraemon movie just started streaming!...”
→I am not sure what “It’s happening!” means in this context. I would suggest that the author(s) delete this part.  This may be minor but I wonder if “Doraemon” is clear to the readers who are not familiar with the Japanese culture. This can also be deleted.

Response 6:
We have deleted “It’s happening!” and “Doraemon.”

Comment 7:
line 40. “Hereinafter, “come/go” is used based on the Japanese forms.”
→What do you mean?  Please add more explanation.  What are “Japanese forms”?

Response 7:
line 56-7. We have clarified the meaning of “Japanese forms” with a brief explanation.

Comment :8
lines 42-3. “The researcher asked “come/go” questions to the participant…”
→Is it possible to add a few examples of the questions used in the study?

Response 8:
line 91-2. We have added an example of a “come/go” question used in Masataka (1998) to provide context.

Comment 9:
lines 48-9. “…Consequently, the following three acquisition sequences were suggested:…”
→I wonder what the author(s) mean by “acquisition sequence.” If Masataka (1998) is a cross-sectional study, how can an acquisition sequence be suggested based on the findings? I think the rationale of this interpretation/argument needs to be presented.

Response 9:
line 88-90. Masataka (1998) is a cohort study, not a cross-sectional study. Data were collected from the same children twice: in first grade and one year later. This longitudinal approach facilitated observation of changes over time, leading to the suggested acquisition sequences. We have revised the text to clarify this.

Comment 10:
lines 91-6. “..We predicted that TD children would move their bodies slightly backward when uttering “come” and forward when uttering “go.” Furthermore, we predicted that this tendency would be stronger in responses to the types of questions that require deictic shifting (e.g., “Will you come to my house to play after school?”) than in types of questions where it is not required (e.g., “Will you go to the library with me?”).”
→It may be better to mention the rationales for each prediction.

Response 10:
lines 150-61. We clarified the basis for our predictions, citing relevant literature (Masataka 1998; Mizuno et al. 2011; Shibamoto 1983) and explaining the cognitive processes involved in deictic shifting. We also addressed the unique aspect of frequent subject omission in Japanese and its potential impact on bodily cues.

2. Materials and Methods

Line-by-line comments

Comment 11:
lines 131-3. “..The first author, serving as the researcher, took on the role of either a child actor or the father of the participating child.”
→Could you clarify what you mean here? Why did the researcher have to take the role of a child actor or the father of the child?

Response 11:
lines 198-200. We have added an explanation to clarify that the researcher assumed various roles to simulate realistic conversational contexts that children might encounter in their daily lives.

Comment 12:
lines 162-4. “..In total, 20 trials were conducted, with each trial consisting of sitting in type-specific positional relations, the cues by clapperboard, the narrations, the researcher’s phrases, and the participant’s phrases, in that order.”
→Could you clarify what you mean here?

Response 12:
lines 234-37. To enable readers to understand the meaning of this description, we have added numbers to each component, corresponding to more detailed explanations provided elsewhere in the manuscript.

3. Results

Comment 13:
Overall, the presentation of the results seems to lack details. I suggest that each analysis be reported more elaborately.

Response 13:
Based on comments from other reviewers, we have added more detailed analysis results (please refer to the Results section).

Line-by-line comments

Comment 14:
line 230. “The participant and overall results are shown in Tables 3 and 4, respectively.”
→Please provide more specific explanations of what is being described in each table.

Response 14:
lines 315-20. We have provided specific descriptions for each table.

4. Discussion

Line-by-line comments

Comment 15:
lines 264-6. “..One of the most significant findings of this study was the suggestion that appropriate verbal responses and body movements based on actual directions appear only in the acquisition stage of “come/go” and subsequently disappear.”
→I wonder which data supports this claim, and where this “suggestion” is mentioned. I think the readers will benefit from more detailed explanation on how the results would lead to this argument.

Response 15:
lines 360-71. We appreciate the opportunity to clarify the connection between our results and our interpretation. Upon careful reconsideration of our findings, we have determined that our initial interpretation was too strong given the cross-sectional nature of our study. We have revised our discussion to more accurately reflect our results.

Comment 16: 
line 273. “…Based on these results, we discussed factors related to the acquisition of deictic verbs regarding spatial perspective-taking”
→Do you mean we “discuss” in the following paragraphs?

Response 16:
line 378. We have clarified that the discussion takes place in the following paragraphs.

Comment 17:
line 333. “…should include not only 6-year-olds but also younger and older children…”
→6 to 7 year-olds?

Response 17:
line 447. We have revised the sentence to accurately reflect the age range of the participants in our study.

Reviewer 3 Report

Comments and Suggestions for Authors

This paper investigates TD children's use of deictic verbs and accompanying body movements. Since prior research was not clear about quantitative data, this research employed a motion-capture tool to measure the body movements and the experimental design was more carefully constructed. The study presents interesting data, such as children were particularly erroneous in the question-answer pair of "come - go", and that the alignment of the use of appropriate deictic verbs and corresponding body movements fades away as children get proficient.

I enjoyed reading the paper, and I found the results very interesting and worth reporting. However, I have several comments and questions as follows.

 

<Abstract>

- Throughout of the paper, the main focus is the perspective shifting of deictic verbs "come" and "go". There is no discussion of "I" and "you" (except for some in the discussion section). I find it confusing that "I" and "you" were mentioned in the abstract.

- The authors mentioned "There is a temporary stage where...": Since this is a pilot study, I think a weaker statement would be more suitable, e.g. "It is possible that there is a temporary stage..."

- The same sentence as above - the authors say "There is a temporary stage where verbal responses align with corresponding body movements", but does "corresponding body movements" mean the correct number of movements, or the amount of the movements? The argument that "this synchronization fades as proficiency increases" is, I thought, based on the negative correlation between the number of correct movements and the amount of the movements. However there is only one pair that was significant (i.e. "come - go"), and the other three pairs had seen overall high accuracy in the first place (and thus I was not sure how to draw conclusions regarding the increase of proficiency). A clearer explanation would be beneficial.

<Introduction>

- l. 37. I have a hard time understanding the quoted sentence: "From Kai's viewpoint, Mio comes to my house." Is it a valid sentence? Isn't it either "From Kai's viewpoint, Mio comes to his house." or, From Kai's viewpoint, "Mio comes to my house."? Please check with a native speaker.

- l. 49. It would be nice if "inappropriate use of "come/go" is explained in more detail. Did the participants use the opposite verb forms? Or switching to other strategy (e.g. using other relevant verbs, or just responding with "yes/no")?

- l. 82. Will you explain why you used the body movements of "backward" and "forward"? How are the movements authorized to represent "come" and "go", respectively? For example, speaking of the "deictic" nature of the movement, it is possible that the speaker's house is located in the direction of the interlocutor (when they are talking face-to-face) and the speaker moves "forward" when they say "Will you come to my house?" How should we understand that moving "backward" and "forward" is natural representations of "come" and "go"?

- l. 82. The same point as above. Aren't there any confounds in changing the manipulation from arms moving (as in Masataka) to body swaying? (I understand that body swaying was better suited for the motion capture method, but I wanted to make sure that it was backed up with some more explanation.)

<Materials and methods>

- l. 119. Regarding PVT-R, the authors say "6 points or above indicates above-average verbal intelligence." However I think it is misleading. On the PVT-R response sheet, SS 1-5 is indicated as "behind", SS 6-8 as "below average", SS 9-11 as "average", SS 12-14 as "above average", SS 15-19 as "excelled".  I think 6 points or above would just mean "not behind". SS 6 would mean below average. I would suggest the authors change the description of "above-average" to something more appropriate.

- l. 159-160. What were the actual instructions?

- l. 165. When they sit side-by-side, did they make (keep) eye contacts? Or, basically they were instructed to look at the screen? To me it seems somewhat unnatural to have a conversation (esp. with a stranger) without making eye contacts when sitting side-by-side.

- l. 178-179. "looked at themselves" "look at themself" Is it a typo for "looked at them/the researcher"?

- Table 2. In Table 2 or possibly in Appendix, it would be helpful if the authors list the stimulus (question) sentences and example of responses in Japanese.

- Table 2. It seems that there are distinct profiles across the four conditions, as to the structural environment where the word come/go appears. Namely, in the "come - come" condition, the prompt was always in the form of "Do you think...?" This probably translates as "... kuru-to omou? (come-complementizer think)". In these sentences, the verb "come" is presented in the default (non-inflected) form. In the "come - go" condition, the prompt was always in the form of "Will you come ...?" This probably translates as "ki-te kureru? (come:continuative-te receive(beneficial light verb))". Or, maybe it was just "kuru? (come)". If the former, the morphology is relatively complex but if the latter, it is not.  I wonder if the former form was used, since in that case a dramatic change of the structural frame would be required in the response, and it is possible that this might have led to a lower accuracy in responses in this condition. One needs to shift the verb (from come to go), and also omit the beneficial light verb and come up with an appropriate response. In the "go - go" condition, the prompt was written as "Will you...?" This could be translated as "it-te kureru? (go:continuative-te receive (beneficial light verb)"/"ik-a-nai? (go:irrealis-a negation)". There are several possibilities and I wonder which form was used. In the "go - come" condition, "go" in the three out of four prompts were used as a light verb, rather than a main verb in the sentence. Also, all the prompts are requesting approval. These would be translated as "mi-ni it-te-mo ii? (see-to go:continuative-te-mo good)". Literally it will be translated as "Is it okay that I go to see it?". The typical response would be "ki-te-mo ii-yo. (come:continuative-te-mo good-particle)". The frame "... te-mo ii" (if it were used in the experiment) could be recycled in the response, so even though one has to shift the perspective (from go to come), the burden to come up with an appropriate response would be lower than that in the "come - go" condition. Just a thought.

<Results>

- Around Table 3. Will you explain what constitutes "wrong" responses? Did they use the opposite verb?

- l. 237-240. I am afraid that I am not following the logic. Why does the correlation infer the difference in magnitude of movement among participants? Will you explain in more detail?

<Discussion>

- First paragraph. If the authors discuss the effect of the "body movements based on actual directions", then I think the point I raised earlier regarding the appropriateness of the natural correspondence between "backward/forward" and "come/go" should be more clearly articulated (in the Introduction section or here). Here is a related naive question: would you predict that the similar argument can be applied to the body movement accompanied by the verbs with different actual movements, such as "walk" vs. "run"? Or does this argument only applicable to the deictic verbs?

- l. 272. The current study showed different results from what is reported in Masataka (1998). I think it should be mentioned (or reminded) that what was measured (arm movement vs. body swaying)  was different in the first place (and thus it might be natural that these two studies yielded different results).

- l. 282-292. I am afraid I am not following the discussion regarding "I" and "you". Will you explain in a bit more detail?

- l. 341-342. Just a comment. Listing some concrete ideas would be more beneficial, I thought. Such as, investigating the correlation between the deictic verb performance and the personal pronouns, or the appropriate use of "come/go" and "kureru/morau", or comparison between production and comprehension.

- Overall: It seems that the arguments sound too strong, considering that this is a pilot study. More hedging words could be used in appropriate parts in Discussion.

Overall, I found the study very intriguing. Some more addition and clarification would make the paper more reader friendly.

Author Response

We sincerely appreciate your thorough and insightful review of our manuscript. Your detailed comments, spanning from the abstract to the discussion, have significantly improved the clarity and precision of our study. We have carefully addressed each of your points by refining our explanations, methodology, and interpretations. Your expertise in linguistic nuances and experimental design have been invaluable in enhancing the overall quality of our study.

Abstract

Comment 1:
Throughout of the paper, the main focus is the perspective shifting of deictic verbs “come” and “go.” There is no discussion of “I” and “you” (except for some in the discussion section). I find it confusing that “I” and “you” were mentioned in the abstract.

Response 1:
line 15. As you correctly pointed out, the focus is on perspective shifting. However, we consider that the term “perspective” itself inherently includes the meanings of “from my perspective” and “from your perspective.” We think that the consistency between the abstract and the main text has been achieved by adding explanations about perspective shifting in the body of the paper (please refer to the main text for details). Nevertheless, to ensure a more accurate description, we have modified the following sentence in the abstract by changing “I/you” to “self/other.”

Comment 2:
The authors mentioned “There is a temporary stage where...”: Since this is a pilot study, I think a weaker statement would be more suitable, e.g. “It is possible that there is...”

Response 2:
line 21. I have revised the text as per your suggestion.

Comment 3:
The same sentence as above - the authors say “There is a temporary stage where verbal responses align with corresponding body movements,” but does “corresponding body movements” mean the correct number of movements, or the amount of the movements? The argument that “this synchronization fades as proficiency increases” is, I thought, based on the negative correlation between the number of correct movements and the amount of the movements. However, there is only one pair that was significant (i.e. “come – go”), and the other three pairs had seen overall high accuracy in the first place (and thus I was not sure how to draw conclusions regarding the increase of proficiency). A clearer explanation would be beneficial.

Response 3:
Lines 21-2. Based on the comments from other reviewers, we have revised the interpretation of results in the Discussion section to reflect what is substantiated by the data (please refer to lines 366-76 and lines 456-66). We have also modified the abstract to align with the revised discussion.

Introduction

Comment 4:
line 37. I have a hard time understanding the quoted sentence: “From Kai's viewpoint, Mio comes to my house.” Is it a valid sentence? Isn’t it either “From Kai's viewpoint, Mio comes to his house.” or, From Kai’s viewpoint, “Mio comes to my house.”? Please check with a native speaker.

Response 4:
lines 54-6. We have revised the sentence to clarify the representation of Kai’s perspective and have consulted with a native English speaker who confirmed that this revised formulation accurately conveys the intended meaning and follows standard English syntax and punctuation rules.

Comment 5:
line 49. It would be nice if “inappropriate use of come/go” is explained in more detail. Did the participants use the opposite verb forms? Or switching to other strategy (e.g. using other relevant verbs, or just responding with “yes/no”)?

Response 5:
lines 98-9. We have clarified that the “inappropriate use of come/go” involved using the opposite verbs.

Comment 6:
line 82. Will you explain why you used the body movements of “backward” and “forward”? How are the movements authorized to represent “come” and “go,” respectively? For example, speaking of the “deictic” nature of the movement, it is possible that the speaker's house is located in the direction of the interlocutor (when they are talking face-to-face) and the speaker moves “forward” when they say “Will you come to my house?” How should we understand that moving “backward” and “forward” is natural representations of “come” and “go”?

Response 6:
lines 136-9. We have added an explanation that the reason for using “backward” and “forward” body movements was primarily to capture more subtle, potentially unconscious reactions. As you have pointed out, we understand that the directionality of movements is relative and can be determined by the position of the speaker's house. However, based on findings from previous research, we explicitly stated in the text that this was specifically in an “experimental” setting, and we consider “backward” to correspond to “come” and “forward” to correspond to “go.”

Comment 7:
line 82. The same point as above. Aren’t there any confounds in changing the manipulation from arms moving (as in Masataka) to body swaying? (I understand that body swaying was better suited for the motion capture method, but I wanted to make sure that it was backed up with some more explanation.)

Response 7:
lines 124-32. As mentioned in our response to the previous comment, we have added a note acknowledging that while there are benefits to adopting body sway measurements, we are aware of the possibility of introducing confounding factors. We have included this as an important consideration in our study.

Materials and methods

Comment 8:
line 119. Regarding PVT-R, the authors say “6 points or above indicates above-average verbal intelligence.” However, I think it is misleading. On the PVT-R response sheet, SS 1-5 is indicated as “behind,” SS 6-8 as “below average,” SS 9-11 as “average,” SS 12-14 as “above average,” SS 15-19 as “excelled.” I think 6 points or above would just mean “not behind.” SS 6 would mean below average. I would suggest the authors change the description of “above-average” to something more appropriate.

Response 8:
line 184. We agree that our original statement was imprecise and could be misleading. Therefore, we have revised the sentence to state that “6 points or above indicates that verbal intelligence is not delayed.”

Comment 9:
lines 159-60. What were the actual instructions?

Response 9:
lines 232. We have added the actual instructions, which were: “When I ask a question, freely say a line using come or go.”

Comment 10:
line 165. When they sit side-by-side, did they make (keep) eye contacts? Or, basically they were instructed to look at the screen? To me it seems somewhat unnatural to have a conversation (esp. with a stranger) without making eye contacts when sitting side-by-side.

Response 10:
lines 240-2. As you have pointed out, participants maintained eye contact while conversing in this seating arrangement. We have revised this portion to clarify that participants were asked to maintain natural eye contact during conversations.

Comment 11:
lines 178-9. “looked at themselves” “look at themselves” Is it a typo for “looked at them/the researcher”?

Response 11:
lines 254-6. We agree and have revised the text accordingly.

Comment 12:
Table 2. In Table 2 or possibly in Appendix A, it would be helpful if the authors list the stimulus (question) sentences and example of responses in Japanese.

Response 12:
We have presented the question sentences and examples of responses in Japanese in Appendix (pages 17-18).

Comment 13:
Table 2. It seems that there are distinct profiles across the four conditions, as to the structural environment where the word come/go appears. Namely, in the “come - come” condition, the prompt was always in the form of “Do you think...?” This probably translates as “... kuru-to omou? (come-complementizer think).” In these sentences, the verb “come” is presented in the default (non-inflected) form. In the “come – go” condition, the prompt was always in the form of “Will you come ...?” This probably translates as “ki-te kureru? (come:continuative-te receive(beneficial light verb).” Or, maybe it was just “kuru? (come).” If the former, the morphology is relatively complex but if the latter, it is not. I wonder if the former form was used, since in that case a dramatic change of the structural frame would be required in the response, and it is possible that this might have led to a lower accuracy in responses in this condition. One needs to shift the verb (from come to go), and also omit the beneficial light verb and come up with an appropriate response. In the “go – go” condition, the prompt was written as “Will you...?” This could be translated as “it-te kureru? (go:continuative-te receive (beneficial light verb)”/“ik-a-nai? (go:irrealis-a negation).” There are several possibilities and I wonder which form was used. In the “go – come” condition, “go” in the three out of four prompts were used as a light verb, rather than a main verb in the sentence. Also, all the prompts are requesting approval. These would be translated as “mi-ni it-te-mo ii? (see-to go:continuative-te-mo good).” Literally it will be translated as “Is it okay that I go to see it?” The typical response would be “ki-te-mo ii-yo (come:continuative-te-mo good-particle).” The frame “... te-mo ii” (if it were used in the experiment) could be recycled in the response, so even though one has to shift the perspective (from go to come), the burden to come up with an appropriate response would be lower than that in the “come – go” condition. Just a thought.

Response 13:
lines 384-91. We greatly appreciate your thorough and insightful analysis of the structural environments across the four conditions. Your detailed explanation has been helpful. Based on your comments, we have carefully discussed the structural environments of the “come? → go” and “go? → come” types and have added a description noting their similarities. Additionally, we have provided detailed structures of each sentence in Appendix A (Table A1).

Results

Comment 14:
Around Table 3. Will you explain what constitutes “wrong” responses? Did they use the opposite verb?

Response 14:
lines 326-8. We agree and have added an explanation stating that all erroneous responses involved saying the line with the opposite verb.

lines 261-4. Additionally, we have added to the procedure that participants were required to respond using either the verb “come” or “go.”

Comment 15:
lines 237-40. I am afraid that I am not following the logic. Why does the correlation infer the difference in magnitude of movement among participants? Will you explain in more detail?

Response 15:
lines 330-6. We have revised our explanation to clarify the logic behind our interpretation of the correlations.

Discussion

Comment 16:
First paragraph. If the authors discuss the effect of the “body movements based on actual directions,” then I think the point I raised earlier regarding the appropriateness of the natural correspondence between “backward/forward” and “come/go” should be more clearly articulated (in the Introduction section or here). Here is a related naive question: would you predict that the similar argument can be applied to the body movement accompanied by the verbs with different actual movements, such as “walk” vs. “run”? Or does this argument only applicable to the deictic verbs?

Response 16:
lines 136-9. I have clarified the basis for the natural correspondence between “backward/forward” and “come/go” in the Introduction section. Specifically, I referenced Masataka’s (1998) findings that forward movement is associated with “go” whereas backward movement is associated with “come” in an experimental setting.

lines 461-4. Furthermore, we have added that for verbs like “walk/run,” similar to “come/go,” a correspondence between words and body movements might be observed, and that this area should be further investigated in future research.

Comment 17:
line 272. The current study showed different results from what is reported in Masataka (1998). I think it should be mentioned (or reminded) that what was measured (arm movement vs. body swaying) was different in the first place (and thus it might be natural that these two studies yielded different results).

Response 17:
line 376-7. We have addressed this point by adding a sentence that explicitly mentions the difference in measurement methods between our study and Masataka (1998).

Comment 18:
lines 282-92. I am afraid I am not following the discussion regarding “I” and “you.” Will you explain in a bit more detail?

Response 18:
lines 393-7. We have added supplementary explanations regarding the transformation from “you” to “I.” It should be noted that we have already elaborated on this transformation process in the introduction while addressing other comments; therefore, we have endeavored to keep the description here concise.

Comment 19:
lines 341-2. Just a comment. Listing some concrete ideas would be more beneficial, I thought. Such as, investigating the correlation between the deictic verb performance and the personal pronouns, or the appropriate use of “come/go” and “kureru/morau,” or comparison between production and comprehension.

Response 19:
lines 453-64. We have incorporated your ideas and expanded the list of concrete research approaches as recommended. Moreover, we have also broadened the scope to include relationships with related areas, providing a more comprehensive view of potential future research directions.

Comment 20:
Overall, It seems that the arguments sound too strong, considering that this is a pilot study. More hedging words could be used in appropriate parts in Discussion.

Response 20:
We have revised the Discussion section, incorporating more hedging language to reflect the preliminary nature of our results.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Overall comment

There has been a significant improvement in the second version of the manuscript. Most of the issues in the review comments have been addressed, and the article is now more elaborate and adequate. readability.  A couple of additional points are addressed below.

 

Line-by-line comments

Lines 51- 

I wonder if it is necessary to explain the difference between Japanese kuru/iku and English come/go.  When asked Uchi ni kuru? “are you coming to my house?” the correct response is Un, iku “yes, I am going”, whereas in English we say “yes, I am coming.”  The explanation on lines 58-9 “Hereafter the usage of “come/go” in English sentences reflects Japanese linguistic conventions” may be referring to this difference but is not clearly explained and those who are not familiar with Japanese may not understand this clearly.

 

Lines 61-62

Can the original Japanese text for each example be added here, so that it will be evident that these are in fact examples in Japanese (not in English)?

 

Line 84

Will you come to my house today?  à Will (you) come to my house today?

 

Line 121-2

“…more than 20 years had passed since Masataka’s (1996) experiments at the time this study was conducted.”

à“…more than 20 years had passed since Masataka’s (1996) experiments at the time this study was conducted.” ?

 

Line 133-5

“Notably, adopting…”

It is not very clear what this statement suggests.  Does it mean that adopting subtle movements may reflect factors unrelated to the current study?

 

Line 533

“Supplement link” indicated here is not available.

 

Lines 467-476

It is not quite clear why “come? → go” did not gain processing stability in the same way as “go? → come”.   It may help the readers understand your point by discussing the difference between the two.

Author Response

Response to Reviewer 2:
We sincerely appreciate your insightful comments and suggestions, which have significantly contributed to improving the clarity and quality of our manuscript.

Comment 1:
Lines 51-. I wonder if it is necessary to explain the difference between Japanese kuru/iku and English come/go. When asked Uchi ni kuru? “are you coming to my house?” the correct response is Un, iku “yes, I am going”, whereas in English we say “yes, I am coming.” The explanation on lines 58-9 “Hereafter the usage of “come/go” in English sentences reflects Japanese linguistic conventions” may be referring to this difference but is not clearly explained and those who are not familiar with Japanese may not understand this clearly.

Response 1:
We agree and have made the following three corrections: (1) To clarify that this study addresses the usage of “come/go” in Japanese, we have moved the sentence “Hereinafter, the usage of ‘come/go’ in English sentences reflects Japanese linguistic conventions” to the beginning (Lines 51-52). (2) We have included the original Japanese sentence for “(I) went to the bookstore last weekend” and removed the corresponding English sentence “I went to the bookstore last weekend” (Lines 70-8). (3) We have eliminated the description contrasting the difference between Japanese kuru/iku and English come/go, which stated: “Conversely, in English, the subject ‘I’ is explicitly included when responding. This highlights the difference in subject explicitness between the two languages, particularly in the pragmatics of deictic verbs.”

Comment 2:
Lines 61-62. Can the original Japanese text for each example be added here, so that it will be evident that these are in fact examples in Japanese (not in English)?

Response 2:
Lines 59-68. Thank you for your suggestion. We have added the original Japanese text for each example. This addition clarifies that these are Japanese examples and also addresses the concern raised in Comment 1.

Comment 3:
Line 84. Will you come to my house today? → Will (you) come to my house today?

Response 3:
Line 89. Taking on your point, we have made the correction.

Comment 4:
Lines 121-2. “…more than 20 years had passed since Masataka’s (1996) experiments at the time this study was conducted.” → “…more than 20 years had passed since Masataka’s (1996) experiments at the time this study was conducted.” ?

Response 4:
Lines 126-27. To be more precise, we intended to refer to the time that had passed since the publication of Masataka’s (1996) paper, not the experiment itself. Therefore, we have revised the sentence.

Comment 5:
Lines 133-5. “Notably, adopting…” It is not very clear what this statement suggests. Does it mean that adopting subtle movements may reflect factors unrelated to the current study?

Response 5:
Lines 383-6. We have removed this description from the Introduction as its inclusion would have been abrupt and lacked clarity in that context. Instead, we have incorporated part of the deleted description into the relevant section of the Discussion.

Comment 6:
Line 533. “Supplement link” indicated here is not available.

Response 6:
Line 506. “Supplement link” is currently represented by placeholder text using “x” as the URL has not yet been assigned by MDPI. We have uploaded the supplementary video to the submission system, but it is not publicly accessible at this stage of the review process.

Comment 7:
Lines 467-76. It is not quite clear why “come? → go” did not gain processing stability in the same way as “go? → come.” It may help the readers understand your point by discussing the difference between the two.

Response 7:
Lines 433-47. Focusing on the difference in the direction of perspective transformations (“you → I” vs. “I → you”), we have added a discussion on the processing stability of “come? → go” and “go? → come.”