Dear Ms Kupers,

Thank you very much for submitting your manuscript "Radial asymmetries around the visual field: From retina to cortex to behavior" for consideration at PLOS Computational Biology.

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Sincerely,

Saad Jbabdi

Associate Editor

PLOS Computational Biology

Wolfgang Einhäuser

Deputy Editor

PLOS Computational Biology

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Reviewer's Responses to Questions

Comments to the Authors:

Please note here if the review is uploaded as an attachment.

Reviewer #1: Review uploaded as an attachment.

Reviewer #2: In “Radial asymmetries around the visual field: From retina to cortex to behavior,” the authors report a suite of insights into neural and perceptual asymmetries along the horizontal and vertical meridians of the retina. This is a thoughtful, detailed, creative, and extremely well written treatment of this issues, which makes several notable advances on prior work on this topic. The author’s recent prior work (also published in PLOS CB) focused on meridional asymmetries in optics and cone photoreceptor density; in the current report there are two key new insights. First, the authors systematically leverage anatomical and functional data to show that these asymmetries are present and amplified at the levels of retinal ganglion cell density and cortical magnification factor in early visual cortex. Second, they show that the spatial filtering properties of midget retinal ganglion cells, combined with asymmetric density long the meridians, augment the predicted asymmetries of observer models, but still do not account for the quite large differences measured in perceptual experiments. My comments that follow are all minor and mostly suggestions for ways to improve the clarity and completeness of the report.

Intro/Terminology: The authors use the term “radial asymmetries” to refer to variations as a function of polar angle (pg 3). I found this confusing. To me, these variations would be more accurately referred to as “polar angle asymmetries” or “meridional asymmetries.” The term, “radial asymmetries” implies that the variations appear as a function of radius. In pg 23, the authors even use the phrase “radial asymmetries” and “polar angle asymmetries” to refer to the same phenomenon of interest in two consecutive sentences. It doesn’t seem appropriate that both of these terms be used to refer to the same thing, and I think the latter is more clear.

Results:

-Pg. 6 (Fig 1): I didn’t understand why the mRGC : V1 CMF ratio decreases again after 20 degrees. Is this expected? It would be helpful if the authors addressed this feature of the data.

-Pg 8 (Fig 2): The CMF data derived from the HCP appear to have quite different mRGC : V1 CMF ratios than the ratios derived when the Horton & Hoyt formula is used (Fig 2B). Some of this difference might be because the HCP data are plotted only for the meridians. Would it be possible to add average lines for the HCP CMF data to Fig 2 panels A and B, for a more direct comparison to the formula overall? I also think the inclusion of V2 in the CMF estimates for the vertical meridian, but not the horizontal, warrants further scrutiny. It seems fair to compare superior and inferior in this regard, but is it really fair to compare horizontal to vertical with these data? In addition to the stated assumption that “V2 is approximately the same size as V1” (pg 29), do other assumptions need to be made about the relative CMF and receptive field sizes in V2 and V1?

-Pg. 12 (Fig 3): I understand that a spiking model isn’t used for the RGCs, but it doesn’t seem appropriate to label RGC responses in units of photons/ms. I’d suggest just calling these arbitrary units.

Pg. 14 (Fig 4): I found panel A confusing, possibly because the locations of the cones were not indicated. Overall, it would be helpful to have a visualization that includes the cone mosaic to show how the mRGCs tile it. Maybe it’s also hard to interpret this figure because the 2:1 ratio is spatially 1:1? (If one linear mRGC represents a pair of ON/OFF cells, pg 31).

Methods:

-Pg. 32: it should be noted that conv2 uses zero padding. It was unclear to me whether the sub-sampling removed any edge samples that include contributions of this padding. Is that the case? If not, does the padding impact the results?

-Pg. 35: I may be missing something, but I didn’t understand why interpolation was used here. Why not train classifiers directly on the appropriate ratios for each meridian at 4.5 deg?

General Formatting:

-In Fig 2, the different lines were hard to distinguish when printed. Given that the number of lines is pretty small, I’d suggest applying different line styles and/or saturations

-In the revised manuscript, it would be helpful to include line numbers in addition to page numbers

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Reviewer #1: Yes

Reviewer #2: None

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Reviewer #1: No

Reviewer #2: No

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Dear Ms Kupers,

We are pleased to inform you that your manuscript 'Asymmetries around the visual field: From retina to cortex to behavior' has been provisionally accepted for publication in PLOS Computational Biology.

Before your manuscript can be formally accepted you will need to complete some formatting changes, which you will receive in a follow up email. A member of our team will be in touch with a set of requests.

Please note that your manuscript will not be scheduled for publication until you have made the required changes, so a swift response is appreciated.

IMPORTANT: The editorial review process is now complete. PLOS will only permit corrections to spelling, formatting or significant scientific errors from this point onwards. Requests for major changes, or any which affect the scientific understanding of your work, will cause delays to the publication date of your manuscript.

Should you, your institution's press office or the journal office choose to press release your paper, you will automatically be opted out of early publication. We ask that you notify us now if you or your institution is planning to press release the article. All press must be co-ordinated with PLOS.

Thank you again for supporting Open Access publishing; we are looking forward to publishing your work in PLOS Computational Biology. 

Best regards,

Saad Jbabdi

Associate Editor

PLOS Computational Biology

Wolfgang Einhäuser

Deputy Editor

PLOS Computational Biology

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Reviewer's Responses to Questions

Comments to the Authors:

Please note here if the review is uploaded as an attachment.

Reviewer #1: The authors have addressed all my points/concerns and I have nothing more to add. Thank you for such a great paper !

Reviewer #2: No further comments.

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Have the authors made all data and (if applicable) computational code underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data and code underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data and code should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data or code —e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: Yes: Nicolas Cottaris

Reviewer #2: No