Nature in the Heart and Mind of the Beholder: Psycho-Emotional and EEG Differences in Perception of Virtual Nature Due to Gender

Round 1

Reviewer 1 Report

Good research and presentation showing the gender difference.

Section 1 and 2 (introduction and Methods and Related work sections can be merged nad be made more concise. Some relevant part may go to discussion. 

Author Response

We sincerely thank the esteemed reviewers for considering our manuscript and making the suggestions for improvement. Our replies to the comments follow.

> Section 1 and 2 (introduction and Methods and Related work sections can be merged nad be made more concise. Some relevant part may go to discussion.

Thank you for the comment, but we decided against shortening the introductory sections and merging them, to adequately present the research problem and the better overview the state-of-the-art; and also because there is a minimum length limit for an Article publication.

Reviewer 2 Report

The article is devoted to the study of the effect of gender on psychophysiological indicators while staying in virtual reality. The Introduction contains information about existing knowledge on the chosen topic. At the end of the Introduction, the authors outline the goal of the research. I suggest putting the past tense in the sentence with the goal of the study (line 50).

I have a few comments about minor article revisions.

The authors should add information about age and gender disparity to the abstract.

Use of a virtual reality helmet may have resulted in distortions and artifacts in the EEG signal. The authors should indicate whether such difficulties occurred and how they handled them.

In the Discussion, authors may also refer to articles using other psychophysiological methods and evaluating user reactions to the scenario in virtual reality. For example, how the situation of winning and losing (which clearly evoke emotions of different valences) affects the heart rhythm.

Given the small volume of the article, I would recommend changing the type of the article to Communication.

Author Response

We sincerely thank the esteemed reviewers for considering our manuscript and making the suggestions for improvement. Our replies to the comments follow.

> At the end of the Introduction, the authors outline the goal of the research. I suggest putting the past tense in the sentence with the goal of the study (line 50).

Thank you for the comment, we have corrected the sentence – it now uses past tense.

> The authors should add information about age and gender disparity to the abstract.

We have modified the Abstract, detailing the findings about the effects of gender. We are not sure about the age disparity though, since we used quite an age-uniform sample in our study (18-23 years old) and did not analyze this factor.

> Use of a virtual reality helmet may have resulted in distortions and artifacts in the EEG signal. The authors should indicate whether such difficulties occurred and how they handled them.

It turned out that there was no considerable increase in artifacts compared to the regular EEG registration (i.e., without a virtual reality helmet). The removal of the artifacts was done using the Independent Component Analysis (ICA). This is now indicated in the manuscript (3.3).

> In the Discussion, authors may also refer to articles using other psychophysiological methods and evaluating user reactions to the scenario in virtual reality. For example, how the situation of winning and losing (which clearly evoke emotions of different valences) affects the heart rhythm.

We have extended the Discussion section, considering some existing methods and the ways the situations might affect the rhythms.

> Given the small volume of the article, I would recommend changing the type of the article to Communication.

We have extended the volume of our manuscript, and would like to keep it being an Article.

Reviewer 3 Report

The authors investigated the effects of 2D and 3D(VR) viewing of nature-related videos on objective (EEG) and subjective measures of mental states. The findings are interesting, but I have the following questions I hope the authors could clarify.

Methods:

1. Could the authors describe the order of the experimental conditions? Did all participants complete the control, 2D, 3D conditions in the same order, or was the order randomized? If the order was the same for all participants, it may confound the findings and should be included as a limitation.

2. For the Environmental Identity Index, could the authors please report the range of scores and what higher scores represent?

Results:

3. The first two paragraphs of the results section actually describe methods, so they should be moved to methods. Also, in the methods section, the authors should list the statistical tests used for analyses.

4. For Table 1, please describe whether the values mean "mean +/- SD" or "mean +/- SE".

5. There are two "Figure 3"s. Please double-check the order and numbering of the figures.

6. For the second Figure 3, because the valence scale ranges from 1 to 9, the y-axis should also range from 1-9. In other words, values between 0 and 1 are impossible, so they should not be included in the y-axis.

Discussion:

7. New results (i.e., the correlations between EEG and EDI) were introduced in the second paragraph of discussion. They should be moved to the results section.

8. Line 316-317: "The relaxation effect found in Alpha2 band in the 3D 316 condition, which was more pronounced in males than in females,..." I'm not sure which part of the results this sentence refers to. It does not seem to correspond to Table 2. Please clarify.

Author Response

We sincerely thank the esteemed reviewers for considering our manuscript and making the suggestions for improvement. Our replies to the comments follow.

> 1. Could the authors describe the order of the experimental conditions? Did all participants complete the control, 2D, 3D conditions in the same order, or was the order randomized? If the order was the same for all participants, it may confound the findings and should be included as a limitation.

Considering the relatively small number of subjects and the expected different individual reactivity to the stimuli presentation in 2D and 3D conditions, we did not alter the order of the experimental conditions. Indeed, it might lead to habituation, but on the other hand negates the individual reactivity. We have now reflected this as a limitation of the study, as suggested by the esteemed reviewer.

> 2. For the Environmental Identity Index, could the authors please report the range of scores and what higher scores represent?

Thank you for the comment. We have expanded the description of the EID in Methods (3.3) and added the perspective on the scores obtained by our subjects in Results (4.1).

> 3. The first two paragraphs of the results section actually describe methods, so they should be moved to methods. Also, in the methods section, the authors should list the statistical tests used for analyses.

We agree with the comment and have moved the two paragraphs to the Methods. We also listed the statistical tests that we use.

> 4. For Table 1, please describe whether the values mean "mean +/- SD" or "mean +/- SE".

The values mean "mean +/- SD": we have now explicitly specified this in the tables’ captions.

> 5. There are two "Figure 3"s. Please double-check the order and numbering of the figures.

Thank you for noting this! We have corrected the figures’ numbers.

> 6. For the second Figure 3, because the valence scale ranges from 1 to 9, the y-axis should also range from 1-9. In other words, values between 0 and 1 are impossible, so they should not be included in the y-axis.

Indeed, the minimum possible value is 1, but we would prefer to keep the axis starting from 0, mostly for the sake of aesthetics. Otherwise, the boxes in the figure would stick to the axis.

> 7. New results (i.e., the correlations between EEG and EDI) were introduced in the second paragraph of discussion. They should be moved to the results section.

We agree with the comment and have moved the text describing the results to the Results section.

> 8. Line 316-317: "The relaxation effect found in Alpha2 band in the 3D 316 condition, which was more pronounced in males than in females,..." I'm not sure which part of the results this sentence refers to. It does not seem to correspond to Table 2. Please clarify.

This sentence indeed refers to Table 2, where we demonstrate that the ln-transformed Alpha2 was higher in men (0.08±0.57) compared to women (-0.29±0.23). We assume that higher Alpha power means lower degree of the brain activation. We have now presented the concrete values in the respective sentence in the Discussion.

Reviewer 4 Report

The authors has presented an emerging technologies implementation for virtual experiences of nature. The presentation of article is well organised, however few changes need to be incorporated for better readability.

1.  In the abstract, the authors are requested to present the numerical findings of study. Along with this, the novelty and future work must be highlighted in the abstract.

2. In the introduction, the authors can correlate the current study with sustainable development goals such as innovation infrastructure and good health and wellbeing 

3. The contribution of the study is missing in the introduction section.

4. A comparative analysis of previous studies must be incorporated in the related works for discussing the limitations of study in detailed.

Author Response

We sincerely thank the esteemed reviewers for considering our manuscript and making the suggestions for improvement. Our replies to the comments follow.

> 1.  In the abstract, the authors are requested to present the numerical findings of study. Along with this, the novelty and future work must be highlighted in the abstract.

According to the suggestion by the esteemed reviewer, we have mentioned the novelty in the Abstract and added some numbers. The plans for future work are presented in the Conclusions.

> 2. In the introduction, the authors can correlate the current study with sustainable development goals such as innovation infrastructure and good health and wellbeing

Thank you for the suggestion, we have added this to the Introduction.

> 3. The contribution of the study is missing in the introduction section.

We have specified the contribution of our study in the Introduction.

> 4. A comparative analysis of previous studies must be incorporated in the related works for discussing the limitations of study in detailed.

As the esteemed reviewer suggested, we have extended the Discussion section with the analysis of previous related studies and the limitations.