American Family Vision Clinic Logo
Authors
Ethan J. Duwell; Erica N. Woertz; Jedidiah Mathis; Joseph Carroll; Edgar A. DeYoe

Aberrant visual population receptive fields in human albinism

publication date
May 2021
Category
see more

Abstract/Introduction

Retinotopic organization is a fundamental feature of visual cortex thought to play a vital role in encoding spatial information. One important aspect of normal retinotopy is the representation of the right and left hemifields in contralateral visual cortex. However, in human albinism, many temporal retinal afferents decussate aberrantly at the optic chiasm resulting in partially superimposed representations of opposite hemifields in each hemisphere of visual cortex. Previous functional magnetic resonance imaging (fMRI) studies in human albinism suggest that the right and left hemifield representations are superimposed in a mirror-symmetric manner. This should produce imaging voxels which respond to two separate locations mirrored across the vertical meridian. However, it is not yet clear how retino-cortical miswiring in albinism manifests at the level of single voxel population receptive fields (pRFs). Here, we used pRF modeling to fit both single and dual pRF models to the visual responses of voxels in visual areas V1 to V3 of five subjects with albinism. We found that subjects with albinism (but not controls) have sizable clusters of voxels with unequivocal dual pRFs consistently corresponding to, but not fully coextensive with, regions of hemifield overlap. These dual pRFs were typically positioned at locations roughly mirrored across the vertical meridian and were uniquely clustered within a portion of the visual field for each subject.


Conclusion/Results

This study shows that retinocortical miswiring in albinism results in single imaging voxels with bilateral dual pRFs. Voxels with dual pRFs are numerous in subjects with albinism but not control subjects and occur selectively in cortical regions where the right and left hemifield representations are superimposed. Our results agree with previous studies which predict that dual pRFs in albinism are positioned at approximately mirror image locations across the VM but suggest that this symmetry is not always precise. Thus, in order to accurately fit responses from all dual pRF voxels, models cannot be rigidly mirror symmetrical, but must instead incorporate some flexibility. Finally, dual pRFs in albinism were not evenly distributed across the visual field, but were instead uniquely clustered within a portion of the visual field for each subject. In the future, mapping subjects’ unique dual pRF distributions could guide spatially focused psychophysical tests aimed at revealing previously undetected perceptual consequences of retinocortical miswiring in albinism.


Testimonials


  • Such a nice optician. My grandson is only 4 and needs glasses. We were so sad, but he explained the issues, and we will follow up as he suggested.


    Anna P.

  • I had such a good experience with the clinic. Very friendly staff and doctor, did not have to wait for long to be called, and was treated respectfully. Thanks, American Family.


    June S.

  • Dr. Zurcher has gone above and beyond what any other eye doctor has ever done to figure out what is going on with my eyes. Very happy with American Family Vision.


    Christine R.

  • Family Vision Clinic changed our lives! My daughter was frequently car sick, and she was getting headaches every day, often painful enough that they brought her to tears. We saw a string of doctors and therapists, but we made no progress. Finally, we found Dr. Levi Zurcher and his eye therapist Rain. After ten weeks of eye therapy my daughter no longer gets headaches, and she no longer gets car sick. Daily tears are a thing of the past. I really can’t say enough about this clinic. It was fascinating to watch Dr. Zurcher work. For the first time, someone who knew what they were doing was intently studying my daughter, really trying to figure out all of her eye issues, and his therapist Rain is one of the most patient and lovely people that I’ve ever had the good fortune to meet. We’re finished with eye therapy—yay!—and I have switched to American Family Vision Clinic for all of my family’s other eye health needs.


    Lars Wulff

  • Very professional, yet kind and helpful. They do what they can to make the appointment comfortable. I was running a bit late, I made sure ti call. They were able to switch me with a patient who was already there, they treated me with respect, and helped my son have confidence by getting him the eye care he needed that day. Thank you so much! Would recommend to anyone. It's a blessing that they care enough to work with people who have all different types of insurance from work to state coverage.


    Justin E.

Blog

Atkinson Hyperlegible Font (1)

Atkinson Hyperlegible Font

Named after Braille Institute founder, J. Robert Atkinson, Atkinson Hyperlegible font is great for low vision readers.  In contrast to […]

Read More
displeased-grey-haired-man-suffers-headache-keeps-hands-head-reveal-pain-needs-painkillers-has-migraine-after-noisy-party-wears-formal-shirt-isolated-brown-wall

Binocular Vision Dysfunction (BVD)

Binocular vision refers to the ability of the eyes to work together. The term binocular vision dysfunction describes a misalignment […]

Read More
woman-putting-eye-drops-sore-eyes (1)

Contact Lens Discomfort Caused by Dry Eyes

Dry eye symptoms are the main reason that most people stop wearing contact lenses. There are many causes and reasons […]

Read More
see all blogs

Contact Us To Amplify Your EyeCare

Working Hours

Monday - Thursday
8:00 am - 5:15pm
friday-sunday
Closed
Location
400 Yauger Way SW. Bldg 1, Ste A Olympia, WA 98502
Website Accessibility Policy
Safety protocols page
phone-handsetarrow-uparrow-right linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram