Review Reports

Round 1

Reviewer 1 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

1.This study focuses on two types of machinery: the harvester and the forwarder. The authors should provide a clear explanation in the background introduction as to why both are considered joint research objects.
2.The authors are advised to label the precise locations of each sensor and device in Figures 2, 3, 4, and 6.
3.It is recommended to include figures beginning in Section 4 to illustrate the data processing flow. This suggestion, however, is not mandatory for manuscripts of the protocol type.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

Congratulations on your work. I have carefully reviewed the manuscript, and you will find my detailed observations and recommendations in the attached Word file. I hope these comments will be useful in strengthening your paper and enhancing its clarity, rigor, and impact.

Yours sincerely,

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

Comments to the Author

The manuscript, titled “The Psychophysiological Interrelationship Between Working Conditions and Stress of Harvester and Forwarder Drivers – a Study Protocol,” proposed a study protocol to study the topic. Several major amendments are recommended to further improve the manuscript.

Abstract:

• When explaining the rationale for the study, the authors highlighted that the potential for hazards may increase stress (lines 15-16). However, it would be better for the justification of the importance of the study by putting it the other way around, highlighting that experiencing stress may increase work hazards.

Introduction:

• The literature review covers the important aspects of the topic, demonstrating depth and breadth of knowledge. I like it that the interpretation of various physiological parameters is included in Section 1.4, e.g., higher eye fixation duration can be interpreted as higher mental effort and task difficulty.
• However, the definition of stress needs to be refined further. In section 1.2, line 62, the statement where mental stress “can be synonymously understood as ‘mental workload’” does not align with the concept of stress. While the definition of mental stress in line 58 does sound like mental workload, having a high mental workload does not necessarily lead to perceived stress. Therefore, mental stress does not represent psychological stress.
• Section 1.3 heading does not seem to represent the content well. The heading suggests that psychological parameters are discussed in the section. However, non-psychological variables are also included here (line 80). Perhaps the heading can be amended to “Factors influencing psychological and behavioral parameters.” Similar issue is found in Section 1.4 (line 109), where machine parameters (performed task) are not “psychophysiological parameter.” Perhaps the heading can be amended to “Assessment of Psychophysiological and Behavioral Parameters.”
• Although eye activity is mentioned, the findings related to Szewczyk et al.’s study (p.1, line 88) do not include findings related to eye activity and the implications (higher eye activity represents what?).
• The hypotheses do not include all psychophysiological parameters.

Experimental Design:

• The study was described as a longitudinal experimental study, but it is best described as a repeated measures correlational study. There is no experimental manipulation in the study, and hence it is not an experimental study.
• It is stated that the data collection will last for 3 years starting from the spring of 2022. By right, the data collection would have been concluded in the spring of 2025, in other words, it is already concluded by the time the paper is published. Would it not be more relevant to publish the protocol before the conclusion of data collection?
• Stress was measured in terms of sleep quality, arousal, joy, strain, quality of life, mental stress, and stress recovery. It should be noted that these are not representative of stress. My suggestions are: 1) instead of stress, the study should not use the term “stress” but other terms instead; or 2) when testing the hypotheses, use only variables that are directly relevant to stress (i.e., stress recovery). Either way, the title, literature review, and aims and hypotheses would need some amendment to reflect the change.
• More details related to the validated questionnaires are needed. It is also not clear why some psychology scales are administered at T1, some at T2, and some at T3. A justification would be helpful.
• Details related to the interviews are needed as well, e.g., the duration of each interview, whether it is done one-on-one, who the interviewers are, and when and where the interviews take place etc.
• The procedure needs more details as well. E.g., informed consent process, briefing, set up and hook up, administration of psychological tests, baseline physiological readings, interview, the duration for each process, compensation etc.
• Explanation is needed to justify why physiological readings are used without any reference to baseline readings.
• Based on the statistical analysis strategy, we can foresee a high volume of analyses without any adjustment to control for the probability of family-wise errors. I would recommend more comprehensive analyses (such as cluster analyses followed by MANOVAs etc) to reduce the number of analyses and hence family-wise errors.
• It is not clear how T1, T2, and T3 data and qualitative data are going to be utilized.

APA format and writing style:

• Page number needed for quotations (e.g., p.1, line 76).
• Need to proofread to increase the readability of the content.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

As all my suggestions were addressed and additional improvements were introduced, the article is currently ready to be published.

Congratulations to the Authors!

Author Response

Dear Reviewer,

Thank you very much for your thoughtful evaluation and generous feedback. We truly appreciate the time you invested and your concluding remark that the article is ready to be published.

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

I thank the authors for taking the time and effort to improve the manuscript. The clarity is definitely improved. However, there are fundamental issues that need to be addressed, e.g., the way the authors understood the concepts of mental stress, mental strain, and mental workload (lines 100-118), the way mental stress and mental strain are measured, and the lack of baseline physiological readings. 

Author Response

Dear Reviewer,

Thank you very much for your thoughtful evaluation. We truly appreciate the time you invested in reviewing our manuscript. Please find the detailed responses below and the corresponding revisions highlighted in red within the re-submitted file. We added a more precise description of the different concepts of mental stress, mental strain, and mental workload. We also provided a more comprehensive explanation regarding the physiological readings.

 

The manuscript has undergone the English Editing Service by MDPI (ID 102114). Please find the certificate in the attachment.

 

The presentation of the results cannot be improved, since no results are provided within this study protocol.

 

Comments 1: However, there are fundamental issues that need to be addressed, e.g., the way the authors understood the concepts of mental stress, mental strain, and mental workload (lines 100-118), the way mental stress and mental strain are measured…

Response 1: Thank you for this comment. Adaptations were made to the description of the concepts to clarify how we understand them (page 2, section 2.2, lines 108-121).

For additional clarification (out of the ISO 10075 standard): In this document, mental workload is considered as an umbrella term encompassing mental stress and mental strain. Mental stress is considered as a neutral term rather than the negative outcome from workload and other factors adopted in other approaches. In this way, it reflects a parallel with the engineering use of the terms stress and strain. Thus, mental stress refers to the causes of mental strain, and mental strain refers to the effects of that stress in the individual. This is consistent with the use of the terms in other ergonomics standards, e.g. on thermal stress (see ISO 7933).

Finally, we want to point out how we aim to measure mental stress and mental strain:

• The BMS Ⅱ measures mental strain aspects, mental fatigue and stress response, monotony and mental satiation according to ISO 10075 (see page 8, section 4.3.1. for a detailed description).
• The OrgFit serves as a measurement for work-related mental stress/external workload (see page 8, section 4.3.2. for a detailed description). 
• The RESTQ-Work measures the balance between strain and recovery (see page 8, section 4.3.2. for a detailed description).
• For additional clarification, please see: The evaluation of psychosocial risks at the workplace and implications for interventions: Results of studies for the development of the instrument OrgFit. Präsentation auf der 15th European Conference of Psychology (ECP), Amsterdam.) [Link to fulltext], page 2 and page 9)

 

 

Comments 2: … and the lack of baseline physiological readings. 

Response 2: Thank you for pointing this out we revised the already provided description into a more comprehensive one (page 13, section 5.2., line 530-535). In addition, we want to clarify, that this protocol focuses on within-person changes in the psychophysiological, event-related responses, rather than comparing the measurements between different persons. Therefore, in our opinion, there is no need to perform baseline readings.

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article describes a study comparing the psychological arousal of harvester and forwarder drivers at two levels of terrain ascent.

The machines and the driver were equipped with a variety of sensors and monitoring devices that measured the driver's psychophysiological parameters. This study also included a very comprehensive assessment of psychological measures, such as driver fatigue, perceived stress levels, well-being parameters, etc.

General comments:

It is not very clear what does “Interrelationship” in the title mean? Do the authors mean “correlation”? “A study protocol” – are the authors proposing a protocol, how the working conditions and stress of drivers should be evaluated/assessed. If so, then also the necessary criteria should be defined and explained in the paper.

Add a space between the number and the % sign, e.g. Line 46 – “60 %” and not “60%” (Line 46, line 256 etc) and between the value and the unit (Line 373 “90 m” instead “90m”, “20 m” instead “20m”).

Line 69 – the term GSR is outdated – in the nowadays publications the term EDA (or skin conductance) is preferred. The authors should consider changing the term to a more appropriate one, EDA. GSR is not a term used in contemporary scientific papers.

Line 193 – A very important part of any EDA analysis is decomposition of the raw signal to SCL and SCR components. What is meant by “GSR peaks” is not entirely clear (e.g. SCR is an EDA peak, usually above the 0.02 uS threshold). The authors should clarify “GSR peaks”.

Line 194 – One of the basic publications on EDA is a very comprehensive book https://link.springer.com/book/10.1007/978-1-4614-1126-0. This reference should be added.

Fatigue (line 84) – please define fatigue here – does this stand for physical, mental, cognitive fatigue?

Section 3.6 and 3.6.1 – the description of the data analysis should be in the Methods section.

 

Specific comments:

Line 158 – What kind of flight do the authors talk about in “simulated flight”?

Line 195 – “GSR values” – do the authors by GSR vales mean the SCL value of the skin conductance signal?

Line 423- if fNIRS was not used, why it is mentioned in the paper? Does this add to the clarity of the text, add new information? If not, it could be removed.

Section 3.6.2 and Table 3 – Here a description of the results of an observed person is shown in detail. Why did the authors select this person? Was it in any way a representative person? What about other participants? Did the study not include 12 participants?

Lines 483 to 485 – where is the resulting correlation presented?

Line 490 – where can the reader see the level of correlation between stress level and the mentioned parameters?

Line 499 – moving artefacts are common limitation factors when using EDA electrodes. Did the authors evaluate the level of change of  EDA signal due to the unwanted changes in positioning and similar sources of moving artefacts when the electrodes were attached to the driver’s foot?

Line 453 – if the authors used eye-tracking, why did they not consider including pupil dilatation as a psychophysiological measure in the study?

The study is very comprehensive, with many objective and perception-based measures. But the results section is rather poor and lacks interpretation. E.g. Figure 3 – why is this figure included in the study? It is interesting, but there is no interpretation of the correlation between HRV and average fixation duration. Figure 2 – the correlations could be calculated. This graph with its (poor) descriptive statistics is not statistically very meaningful.

The Conclusions does not contain any firm, concrete and straightforward conclusions drawn from the study. They merely consist of some general remarks. If a new protocol is proposed, the main parameters to be observed and their target values/thresholds/limit values should be specified. It is not clear what the aim of the paper was.

 

 

 

 

 

 

 

Reviewer 2 Report

Comments and Suggestions for Authors

This should have been a well done research that could capture the interest of readers, but there are significant issues with the organization of the manuscript:

1. It is recommended that authors provide detailed information on the devices used and provide on-site photos of their installation and use.

2. It is recommended that authors use more figures to present their data and conduct detailed analysis of the data, rather than simply describing their work through text.

3. The authors' description of the conclusion is very unprofessional. They are more like introducing what they have done, rather than summarizing the conclusions drawn from the data.

In summary, there are too many textual descriptions in this manuscript, lacking quantitative results and detailed data analysis, as well as valuable conclusions. It is recommended that the authors reorganize and resubmit their manuscript.