How does stress influence psychological and biological responses to uncontrollable threat?

Firstly, I want to apologise for the delay in responding to the review request due to many commitments and unforeseen illness. 

I have now read through the revised manuscript and the authors' responses to all reviewer comments. I very much appreciate the thorough responses which clarified all my questions. I believe the manuscript to be much improved and I am looking forward to the results of this interesting study!

Thank you for the opportunity to review this RR in Stage 1. I believe the authors have revised the RR very well. I am satisfied with their responses and the changes they made based on all the reviewers' comments. I am excited to see the results!

Thank you to the authors for their detailed and thoughtful responses to the reviews. I am particularly glad to see the attempt at better powering the study. I think in an ideal world you would follow Brysbaert’s recommendation for between-subject effects (N = 200) but the increase made here can only help you find better evidence for your hypotheses. 

Just a small note that line 135 still says 96 participants (hasn’t been updated to 128).

I think you can make it even more explicit which hypotheses are your main ones and which are additional — in the responses, you wrote H6-8 are secondary but the paper seems to say that everything after H5 are secondary (line 154).

Re hypothesis 8, I am glad the authors added a specific hypothesis for this but I still think the results won’t really tell you much even if you find an association. I would just advise that you make it more explicit that any results found here should be approached with caution at Stage 2.

Re the connection to real-world evidence, I didn’t see where this was added in tracked in the intro but happy for the authors to expand more on it in the discussion at Stage 2.

Re the unpublished study on line 138, can the authors add a link to the OSF repository you mentioned in the reply? I think that will help it be less vague.

Once these minor updates are made, the paper is good to be conducted from my side and I don't need to review it again. I wish the authors good luck with the study and would be happy to review the paper again at Stage 2. 

Best wishes,

Mariela 

The authors plan to investigate the effects of exposure to acute stress on perceived, biological, and physiological stress reactions in response to loss of control. The study is relevant, very well thought out, and the methods are described in great detail. I only have a few questions and points that could be addressed to further improve the planned investigation:

Participants:

• Is there a max. age for recruitment?

MAST task:

• In case participants do not make (m)any mistake(s), I assume they are interrupted with the instruction to “count faster”. This could be made a bit clearer.
• Previous studies have shown that experimenter characteristics (sex, race) can influence experimental pain tolerance, so it would probably be good to either keep the sex of the experimenters the same for all participants or at least document it and potentially include it as a covariate in analyses.

US calibration procedure and stimulation:

• Please elaborate a bit more on the calibration
  • Why did you decide on the max. duration of 2.8 s? Will the durations vary during the task? How?
  • What are the intervals for the gradual increase? Are they always the same?
  • If participants know the intensity is gradually increasing, might they not be tempted to report a higher intensity than they actually perceived to ensure less uncomfortable stimulation during the task? I appreciate that you plan to ask them whether they would like to try one level higher, but it might be helpful to jump up and down a bit during the calibration so you catch participants who deliberately misreport their perception. It may also be helpful to just emphasise at the start that perception of the stimulus varies a lot between individuals and that it is not a competition about who picks the highest intensity.
• Will the electrode be attached to participants’ non-dominant forearm?  I would recommend that so there’s less risk of electrodes detaching during task-related movement of the dominant hand.

Self-reports/Procedure:

• Please explain how you chose the time points for collection of control expectancy reports. If asked just before the US calibration, do participants refer to control over that or over the MAST? Why not also ask at t40?

Yoking:

• I would suggest selecting participants from the previous study who did not consistently show very high accuracy rates and short RTs because then the stimulation would still terminate almost immediately in most trials and participants in the current study might not actually perceive any loss of control.

Data processing:

• Please specify the temperature of the low-temperature freezer
• Will participants with missing blood pressure etc. still be included in the other analyses to avoid loosing too much data?

Analysis:

• H1d - it might also be interesting to look at changes in PSS
• To conclude evidence of absence from null results, it would be better to employ a method such as Bayesian hypothesis testing or frequentist equivalence testing

Other:

• Maybe explain in half a sentence why you decided to include a filler task
• “BS” is a bit of an unfortunate abbreviation, I think :)
• Typo in line 465: I think it should be “their BELIEF of the deception”
• If you have time, it might be interesting to also collect baseline data on participants perceived self-efficacy/locus of control which should be related to control expectancy and could provide interesting results in terms of inter-individual differences

Dudziak and colleagues proposed a well-thought-out study plan to investigate stress and its role in low-control contexts involving an aversive stimulus. They provided an extensive yet clear motivation to address questions related to instrumental conditioning, loss of control, and stress, thereby bridging classical associative learning with clinical perspectives. The hypotheses are solid and supported by a relatively broad range of literature. The authors' analysis strategies are excellent. I also appreciate that the authors openly included the exclusion criteria and addressed the possibility of the data being abnormally distributed by providing non-parametric tests as alternatives to the proposed ones.

I have a few comments and suggestions:

1. Loss-of-Control Task: The newly developed task has really interesting components and has been described extensively. It is mentioned in lines 371–372 that presenting crossed-out buttons would ameliorate the perceived loss of control. I’m not entirely sure if that would achieve the intended effect. I would think that seeing crossed-out buttons might actually reinforce the idea that the shocks are unstoppable, thereby decreasing motivation to try (they might still try anyway, given the yoked duration). Consider this: wouldn’t the perceived loss of control be more pronounced if participants saw a normal button (not crossed out), tried to press it, but failed to stop the shock? Wouldn’t that reset their expectations, making them re-learn their perception of control? Looking back at original learned helplessness studies (e.g., Hiroto & Seligman, 1975; Burger and Arkin, 1980), the tools were not labeled “unsolvable” or “unstoppable,” most likely for these reasons.
2. Duration and Yoking Procedure: It is great to see the yoking procedure being implemented in this task, even though it may be computationally complicated. The authors might want to consider reporting the mean duration participants took to stop the shock during controllable trials (blocks 1–3) and comparing the latencies between the stress and non-stress groups. If there were differences, it could be an interesting effect to report.
3. Blocking: Four trials per block were intended in the experiment. I wonder whether asking participants to rate how stressed and fearful they feel after every block might distract them from the learning process.
4. Physiological Responses: The authors outlined plans to analyze blood pressure and heart rate at specific time points. I am also wondering about the possibility of including continuous physiological recordings during the experiment, as they could complement the ratings of stress and loss of control. Parameters like SCR or any ECG-related measures (e.g., HRV or heart period) could also be interesting in this context.

Lastly, I appreciate the authors' interest in investigating the relationship between the aforementioned variables and childhood adversity. This could have significant clinical implications. Good luck with the data collection!

Signed,
Genisius Hartanto