PREreview of Behavioral Effects of Acetaminophen During a Scary Experience

Manuscript Summarized

Though Acetaminophen or Paracetamol could lessen the emotional response to pain, these findings were either objective neural or self-report measures. As behavioral effects were of interest, participants (n = 260) were assigned Acetaminophen or placebo before entering a simulated virtual reality experiment. The Acetaminophen group recorded faster reaction times and lower heart rates than the placebo group.

Major Comments

1. The introduction is satisfactory. Certain claims by the researchers (e.g., last sentence of paragraph 2 on page 3) were asserted but not supported enough by sources. Unless particular sentences from the introduction section were considered by the researchers as common knowledge, it could be argued the premise this study is building on (see pages 3 to 4) is quite shaky. Such observation may not be easily seen by the casual reader, but rather it is something that fellow researchers could see as they evaluate the clarity and coherence of the arguments presented (I can elaborate further with the order of sentences for selected paragraphs lifted from the introduction section).

   • The introduction’s first paragraph shared why people feel emotions. It is followed by how vital emotions are for adaptive responding. Examples supplemented such. This paragraph ends with more details on the nature of emotions.

   • The next paragraph explains how dynamic emotions can be (though the term used here is behavior) with an example. Acetaminophen is briefly introduced. This paragraph ends with how its mechanism is as dynamic as the “behaviors” explained in this sentence.

   • In the first two paragraphs, I commend the researchers for using a concise style in their write-up to establish their research territory. However, I argue the coherence of this write-up needs to be improved. I highlight more observations that can help the researchers should they pursue revisions:

     • I do not see the relevance of the first sentence of the first paragraph to this study. I could see the opportunity to rather use this first sentence either in the discussion or conclusion sections of this study. My critique is the first paragraph could work more effectively having only sentences 2 and 3.

     • By close reading, the transition between the first two paragraphs of the introduction seems lost. Following this section, the transition goes from “what emotions are” to “an inference of how dynamic emotions can be.” If my critique is considered (sticking to only sentences 2 and 3 for the first paragraph), the transition between the first two paragraphs can be better appreciated by a reader, especially one with no background about the topic.

     • The first sentence of the second paragraph is a well-written inference. However, the sentence highlighting the example does not jive well as the drug was introduced in the same paragraph (I could also argue that introducing the drug could stand as another paragraph). I find it better suited to include another appropriate example to complement the second paragraph’s first sentence. If this critique is considered, it would make more sense to place the last sentence of the second paragraph as intended by the researchers.

   • I hope this evaluation of the first two paragraphs helps the researchers understand where this critique on establishing a research territory (Swales & Feak, 2013) is coming from. These initial comments will be helpful in further improving this manuscript’s introduction section.

2. The following study is an unreplicated experiment. The researchers performed convenience sampling haphazardly through their participant pool (i.e., by using SONA and posting flyers on their campus). Though double-blind blocked randomization was performed for capsule assignment, I appraise the steps outlined in the methods:

   • Though it is advantageous to include an overview of the methods, including the original long hyperlinks for the supplementary materials (see page 6) seems like clutter to the manuscript.

   • The researchers’ measures to handle missing data or outliers (see page 7) are commendable.

   • The study employed Level 3 subheadings (if APA 7 were to be followed) for data to be collected during the experiment (see pages 7 to 9). I appreciate the narrative needed to describe these steps.

   • The researchers measured fear and baseline height of fear by self-report. However, no data on relevant reliability or validity estimates (e.g., coefficient alpha or omega) were included in the study (see page 9).

   • Only the corresponding generic name of the drug of interest (i.e., Acetaminophen) was present in the methods section (see page 10). For other scholars from different disciplines, reliance on the generic drug name could seem insufficient.

   • This study compared two groups: one for Acetaminophen (n = 129) and another for placebo (n = 131). In reality, these are all subsamples. Ergo, this study has 129 subsamples for the Acetaminophen group and 131 for the placebo group.

   • Given the sampling performed, there is only one replicate per group for the researchers to analyze. Hence, there is no need to perform any statistical analysis with two replicates supposed to be compared by the researchers.

3. The following study committed pseudoreplication (Hurlbert, 1984) as the researchers treated the subsamples as replicates. Hence, they pursued their original data analysis plan with such an idea in mind (as reported in the results section). Similarly, the researchers failed to report what statistical software (and what model or version) was used for their data.

4. Since the reported work committed pseudoreplication, I do not advise the researchers to arrive at inferences with how they treated their data set. The final sentence of the discussion’s first paragraph (see page 17) is yet to be true. There is also not enough evidence to make the first sentence claim of the third discussion paragraph (see page 18). Ergo, the reported data in this manuscript is not yet “the first to demonstrate that acetaminophen reduces heart rate.” These are just two findings from the manuscript that I implore the researchers to get back to once again.

5. There are cited publications in your work that are affiliated with predatory journals (e.g., Frontiers).

Minor Comments

1. I noticed that the researchers used first-person reportage for their manuscript. I see no issue with such. However, please consider most journals would require the third-person style for certain experiments like your work.

2. The running head had the conjunction “and” used.

3. I have notable observations with your references.

   • Please determine what edition of the APA style you are using. Certain conventions (e.g., for book chapters or articles with article numbers in lieu of page numbers) are determined by which edition the researchers adhere to.

   • Consistency of title case on journals cited (see Foster et al., 2014 in the references) was not followed for some sources. A hyphen was used instead of an en-dash for page ranges.

   • Most cited works are from the late 2010s with likely available digital object identifiers (DOIs). However, no DOIs were included in this manuscript.

   • I see no problem with the researchers citing earlier works (especially if they are considered seminal).

Recommendations for All Comments

1. I hope the following suggestions on major comments can help improve this manuscript:

   • The introduction section could be rewritten. I recommend adding suitable transitions and appropriate premises (not only reviewing the first two paragraphs but the entire introduction section) that can better strengthen the coherence of arguments being imposed by the researchers. I also suggest not to interchange terms (e.g., how the manuscript could use behavior or emotion for the second paragraph), unless the researchers would find a proper way to make such an arrangement, so the reader does not get confused.

   • I share these suggestions for the methods:

     • The experiment could be repeated. I recommend performing and calling it instead a mensurative experiment (rather than pursuing an unreplicated one) with steps in mind to ensure the right amount of replicates (or necessary subsamples) needed to meet this study’s goals. Only then can the researchers perform the originally planned data analysis correctly.

     • Please include your reportage the IUPAC name of any chemical or drug compound you will use for this study (such a step is helpful for standardization and applicability when future scholars will read on your work). PubChem is a good place to start to learn more from this.

     • To improve on the steps needed to collect your data, I highly recommend tabulating what you intend to collect (e.g., time to step on the plank, distance, walking speed). Having these portions of the methods tabulated also helps guide the reader on how the experiment was conducted.

     • Please report relevant reliability or validity estimates for the objective personality measures used in the study.

     • Please report what statistical software and what versions were used when accomplishing the data analysis plan.

   • I highly suggest replacing the cited sources from predatory journals with nonpredatory works.

2. I hope the following suggestions on minor comments can help improve this manuscript:

   • If applicable, please convert the manuscript to the third person.

   • You can instead replace “and” with “&” for the running head.

   • Please follow the APA format based on the edition you intend to use. Print and online materials are available to guide you with this suggestion.

Competing interests

The author declares that they have no competing interests.