Title: Association between Resting-state EEG oscillation and psychometric properties in
perimenopausal women
Version: 1 Date: 17 Jan 2022
Reviewer:  Diana Karamacoska
Reviewer's report:
General comments
It’s great to see innovative and novel neurophysiological work being conducted for a cohort that
is exposed to significant health risks during this transitional life stage.  This study is interesting,
but there are concerns regarding the justification of such research and its methodology that
require clarification and correction from the authors.
I would encourage the authors to use the names of the EEG bands (delta, theta, alpha, beta, and
gamma) instead of their symbols as the names function as keywords in databases.  For example,
when other researchers perform searches for EEG papers, they will typically input ‘beta’ in the
search bar, rather than inserting the symbol.
Whilst no other resting state EEG studies may exist for this population/group of women, there is
no indication as to whether studies of the DI, SAI BIS, and IS exist for perimenopausal women.
Could the authors conduct a literature review to identify whether such studies exist, and comment
on what the norms and/or clinical relevance of these inventories are?  This material should be
worked into the introduction, and discussed in the context of the current study’s distribution of
DI, SAI, BIS, and IS scores.
There were some grammatical and spelling errors noted throughout, however, I will leave this
to the journal editors to amend.
Abstract
Background
A stronger justification for the purpose of this study is needed.  Why is it important to assess
resting state EEG in perimenopausal women?
Methods
State what the EEG recording involved and what unit of measurement is being used for EEG
band power (i.e., absolute or relative).
Results
The first result discussed relates to # (beta) power, but this band isn’t listed in the Methods
section - only delta, theta, alpha and gamma are.
Conclusion
The implication suggested for this research doesn’t hold any clinical value.  Why would
clinicians be interested in the EEG of perimenopausal women?  How does beta and/or
impulsivity in this context warrant clinical investigation?  Work is needed to explain the
justification in the background and conclusion sections of the abstract.
Introduction
Please reference the statement “These emotions have a major influence on social cognitive
processes, which, in turn, influence life outcomes.”
The introductory material provides an overview of the perimenopause period, highlighting the
mental health issues that can arise during this time.  However, it jumps to an idea that biomarkers
for early stage cognitive decline are needed; without providing any context to this issue.  Why is
it important for such biomarkers to be established?  Are women at an increased risk of developing
cognitive decline or dementia? If so, then such justifications should be made explicit here.
Please reference the sentence “rsEEG signals are composed of multiple waves cycling at
different frequencies: # (0.5#4 Hz), # (4#8 Hz), # (8#13 Hz), # (13#30 Hz),and # (31#40 Hz).”
“Such work is necessary, as this potential neural entrainment is not completely covered in
literature . Thus, the examination of resting state EEG data may enhance our understanding
of basic brain function”  << this is not a strong enough justification for conducting research.
Pleas enhance your argument by linking this exploration back to the clinical importance of
perimenopause i.e., it is a life stage for women associated with the onset of mental and cognitive
health issues
Rather than listing the psychological inventories selected for use in this study, can the authors
explain the relevance of these to perimenopause?  That is, what are the norms and clinical
relevance of these inventories for perimenopause?
Method
Participants – how were they recruited for the study? Did they have any vision or hearing
impairments that would affect their participation?
EEG recording –
In reference to the following statement: “standard 10 20 system covering symmetrical brain
areas: the anterofrontal, frontal, anterotemporal, temporal, posterior temporal, central, parietal,
and occipital regions Figure 1)”. Figure 1 shows the electrode placements, but doesn’t explain
where these brain areas are.
Was bandpass filtering applied before or after the recording?  I’m also very concerned about the
bandpass filter settings used as data outside of 70 and 250 Hz was filtered, meaning you have
captured the activity between 70 and 250 Hz, and are not reliably measuring the low to high
EEG activity of interest in this study, which ranges from 0.5 to 40 Hz.
What do the authors mean with this statement “Accepted epochs were used as baselines”.
Typically, a baseline-correction is applied to all accepted epochs.
Results
Descriptive statistics – there is no indication as to whether the means and standard deviations
were normally distributed.
The methods used to examine the relationship between EEG activity and psychometric
properties are not statistically sound.  The authors need to correct for having conducted multiple
tests with the same data i.e., correlating the electrode data with a psychometric score and then
averaging the same electrode data and correlating it again with psychometric scores.  Consider
applying a Bonferonni correction to the second test or any other appropriate p-correcting method.
Discussion
Please reference the statement “The IS questionnaire was used to assess sense of urgency,
premeditation, perseverance, and sensation seeking, all factors in impulsive behavior.”
“We highlighted an intrinsic # power signature as an important correlate of degree of impulsivity
thereby making it a potential biomarker for perimenopausal women.” – this statement needs
clarification regarding this ‘biomarker’ use.  What kind of biomarker application does this
finding have? Has impulsivity been linked to anything specific or clinically serious for
perimenopausal women where such a biomarker would have value?
The third paragraph in the discussion, beginning with sentence “The spectral power distribution
of each band is presented in Table 2 Spontaneous neural”, is not appropriate for discussion
given you didn’t statistically test the locality of EEG activity or include functional connectivity
measures.  As there are no results pertaining to this, I’d encourage the authors to consider
removing this paragraph.
Please revise this sentence as it currently does not make sense: “For the perimenopause
emotional vulnerability that toward tracking band power modulation by various interventions
such as neurofeedback or meditation for psychological well-being across the lifespan should be
considered a women’s health issue.”
The limitations provided at the end of this section are vague.  What kind of control group is
needed to improve the study’s robustness?
The following sentence also needs to be revised for clarity: “The current study did not address
activity in specific brain regions when analyzing affective function. Such as the DI, AI, and
BIS would assembly surrounded links frontal alpha asymmetry had established in previously
studies.”