Visual Memory Scan Slopes: Their Changes over the First Two Seconds of Processing

Round 1

Reviewer 1 Report

The authors described in this manuscript the stages of information processing in visual memory. The study is the continuation of a previous investigation in which only 1 item was presented. At present, 1, 3 and 5 items were displayed to calculate the visual memory capacity, the visual memory capacity slopes and the visual memory scanning slopes. They found, as in the previous investigation, three stages of visual memory processing. Results in visual memory scan slopes are very interesting, as well as the results related to the characteristics of the items.

Here are some points that could improve the manuscript.  Specifically, I have a great concern about the methodology and the statistical analysis. The sample used is very small, so authors need to justify the sample size with some data that is not reflected in the manuscript.

Introduction

I have a personal feeling that the information of this section needs to be organized.

In the Introduction section you start speaking about the theory in an unexpected way. I propose that you explain here why your study is important and why you want to complete the previous Jacob’s study. For and why is it interesting or necessary to carry out this research?

In the second section (1.1) you explain briefly why you need to complete the Jacob’s study, but it is important to highlight the repercussion that it could have.

On the other hand, you should first describe the theory that supports your hypothesis and then write them in a list. You present the hypothesis in a list throughout the text with numbers in the middle and in different paragraphs. This makes reading it difficult. Moreover, two lists of hypotheses could be repetitive.

For a better understanding of the reader, I think you should describe the “scan” and “scan slope” concepts and differentiate them.

2.1. Participants

How did you present the instructions to the participants?

Were they volunteers or did you select them? Did you ask if they had any neurological or psychological disorders that could affect their cognitive performance? Did you ask them if they used drugs or if they were on drug treatment?  I suggest you add all this information (if you have it).

The sample is very small. I think you should add more participants or justify the sample size with statistical data.

Line 124 - You should add an additional section (2.4) to describe the analysis procedure (the use of ANOVA, indicate the post hoc test you used, the statistical programs you used to analyze the data, the limit of the p-value…).

3. Results and Discussion

Did you use any normality test as the Shapiro-Wilk? With a sample of 9 subjects it is very important to know if the sample shows a normal distribution.

Did you use any homocedasticity test? You must also add this information.

Did you calculate the statistical power? Due to the so small sample, I think it is important add the statistical power.

References

The bibliography is very old.

 

Minors

Line 21 – there is a comma after the last keyword.

Figure 1 should not be in the middle of a paragraph because it cuts the lecture of the paragraph. Better place it at the end of the paragraph.

Figure 2 should be after line 107, where it is referenced.

I would delete the two subsections 1.1 and 1.2 and join all the information.

The K abbreviation in line 47 cannot be understood until line 66.

Line 66 – there is no reference after “in the Jacob et al. study”.

I would place Figure 5 after line 190 and Figure 6 after line 216.

Figures without colors (3 A and B, 4 and 5 A): it is difficult to distinguish between “color” and “overall”.

Figure 5A: I would write the legend in the same order as the legends of the previous figures (first “shape”, second “color” and third “overall”).

Author Response

Note to both Reviewers: In the Abstract and the main text, we no longer refer to visual memory (VM) but to visual short-term memory (VSTM), composed successively of three phases or stages: sensory visible memory (SVP), sensory informational memory (SIP), and visual working memory (VWM). These terms and their acronyms are introduced in the highlighted section of the Abstract and the highlighted section near the beginning of the Introduction.

Response to Reviewer 1:

1. Regarding Reviewer 1’s general comment about methodology and statistical analysis: we have noted here that the successfully recruited participants were limited to 9, because the study reported in the current paper was one of two studies, in which 16 recruits originally agreed to participate. Since the voluntary consent allowed the original recruits to drop out of participation for any reason, those that actually finished both studies was reduced to 9. Also, we have included the power of our statistical tests in all of our ANOVA results.
2. Regarding Reviewer 1’s comments about the Introduction, these are addressed in the new (highlighted) Sections 1.1 and 1.2.
3. Reviewer 1’s comments about Section 2.1 Participants, are addressed in the highlighted section of Section 2.1. We assumed that the participants were healthy. We therefore did not screen participants on the basis of neurological or psychological disorders, nor on the basis of drug use or drug treatment. We also included how participants were instructed/familiarized bout their task. Our use of a small sample is given in Response 1.
4. We also added, as requested, a brief (highlighted) Section 2.4 on statistical methods.
5. Regarding Reviewer 1’s comments on the 3. Results and Discussion section, we cover the outcomes of normality and homoscedasticity tests of our data in the new (highlighted) Section 3.1. The outcomes are listed in Appendix 1, 1 showing a table of results of the tests inserted after line 392. We have also included power statistics for all ANOVA F tests.
6. They are listed in Appendix 1 (line 387). We also have included the power of our significant AVOVA outcomes.
7. Regarding Reviewer 1’s minor comments, the placing of the figures is constrained by the MS Word styling format that is used for publication in Vision. If we significantly change the location of the figure inserts, the result are often large empty spaces in the text. We have chosen our figure so as not to have blank spaces on any page, although this does add inconvenience to the reading of the text. Regarding the placing of Figures 5 and 6, we have now combined the former Figures 6 and 7 into a new Figure 6.

Reviewer 2 Report

The paper is interesting and it treats an important topic. However, the following changes and clarifications must be implemented prior to publication.

1. Fig 1. Is this from an actual experiment with participants. More details should be added when the figure is referenced and in the text.
2. Fig 3 seems to be scanned from another source or is it original? The figure should be separated into 3a, 3b, 3c ....
3. Applications of this work to real scenarios should be mentioned and referenced.
4. The presented results and figures seem to have a strong connection with the experimental results in 'memory pattern identification for feedback tracking control in human–machine systems' and 'extended crossover model for human-control of fractional order plants'. In particular. These results should be compared for corraboration/contradiction assessment. 
5. The paper should make more clear what is the novelty of the research as compared to the existing literature.
6. More details about the experiments are necessary, such as age, gender of participants, etc.
7. Why only 9 participants? With respect to this, what was the power of the statistical analysis performed?

Author Response

Note to both Reviewers: In the Abstract and the main text, we no longer refer to visual memory (VM) but to visual short-term memory (VSTM), composed successively of three phases or stages: sensory visible memory (SVP), sensory informational memory (SIP), and visual working memory (VWM). These terms and their acronyms are introduced in the highlighted section of the Abstract and the highlighted section near the beginning of the Introduction.

Response to Reviewer 2:

1. Comment 1: we have detailed discussion of Jacob et al.’s results shown in Figure 1, in the new (highlighted) Section 1.1.
2. Comment 2: Figure 3 was not scanned in; it was created by us.
3. Comment 3 and
4. Comment 4: We changed/added a new (highlighted) Section 4.3 in the Discussion section to deal with the relation of our findings to ecological/real-life implications and to the prior findings by Martinez-Garcia et al. that Reviewer referred to.
5. Comment 5: The importance and novelty of our research is discussed in Section 1.2, lines 80-90.
6. Comment 6: We have added the requested information in Section 2.1, lines 106-108.
7. Comment 7: The successfully recruited participants were limited to 9, because the study reported in the current paper was one of two studies, in which 16 recruits originally agreed to participate. Since the voluntary consent allowed the original recruits to drop out of participation for any reason, those that actually finished both studies was reduced to 9. Also, we have included the power of our statistical tests in all of our ANOVA results.

Round 2

Reviewer 1 Report

I appreciate the efforts of the authors, who rewrote various parts of the manuscript following my recommendations. But I am afraid that I still see some important aspects to improve.

- Line 140 – It is necessary to specificity the post hoc test used.

- Line 164, as an example - The p-value has been expressed with the symbol “<”. I think you wanted to write the symbol “=” because it does not match the information provided on Line 140 (“Lower p values were shown as p < .001.”). This error is repeated throughout the Results section and in Figure 3-B.

Minors

Line 21 – there is a comma after the last keyword.

Author Response

So sorry for our not catching the mistakes you noted in our first revision.

1. Regarding your request to specify the post-hoc test we used, it is now listed in the highlighted text of line 140 as “t-test”.
2. Regarding the errors made in not listing exact p values when they were greater than .001, we have made those corrections in the highlighted texts of our statistical results and in Figure 3(B). We should note that when we combined two statistical effects in the text, we used p ≤ .xxx to indicate that one of the statistical effects was significant at exactly p = .xxx, while the other was significant at p < .xxx.

Thanks for your patience.

Reviewer 2 Report

The paper is ready for publication. I do not have further comments.

Author Response

Thank you for you review.