Authors
RIDDER, WILLIAM H. III,, OD, PhD, FAAO; BORSTING, ERIC, OD, MS, FAAO; BANTON, TOM, OD, PhD

All Developmental Dyslexic Subtypes Display an Elevated Motion Coherence Threshold

publication date
May 21, 2019
Category
see more

Abstract/Introduction

Purpose

Psychophysical studies indicate that many dyslexics have a motion-processing deficit. The purpose of this study was to determine whether elevated motion coherence thresholds correlate with the specific dyslexic subtypes as defined by the Boder classification scheme.

 

Methods

Twenty-one dyslexics (seven dyseidetics, six dysphonetics, and eight dysphoneidetics) and 19 age- and gender-matched controls participated in the study. The dyslexics were identified by an exclusionary approach and then subtyped with the Adult Dyslexia Test or the Dyslexia Determination Test. Motion coherence thresholds were determined with random dot kinematograms composed of signal dots and noise dots. Signal dots moved either left or right on each trial, whereas noise dots moved in random directions. The percentage of dots that comprised the signal was varied randomly on each trial (0 to 21% in 3% increments). Subjects guessed the direction of signal dot motion on each trial (two-alternative forced-choice task). A 75% correct threshold was determined with a Weibull equation fit to the psychometric function.


Conclusion/Results

Results

All three dyslexic subtypes had elevated motion coherence thresholds (t-test; dyseidetics p = 0.01, dysphonetics p = 0.039, dysphoneidetics p = 0.048).

 

Conclusion

Motion-coherence deficits are not correlated with a specific dyslexic subtype, but, rather, are common to all subtypes. However, some individuals in each of the dyslexic subtypes were found to have normal motion coherence thresholds, suggesting that other factors must be considered to predict the motion sensitivity deficits found in dyslexia.


Testimonials


  • I haven't actually used the optometrist side, so my review is limited to the vision therapy offered.  This office was recommended by my occupational therapist for the treatment of my double vision following a stroke.


    Claire A.

  • Love this location. I had a brain injury accident from day one one. All the team make you feel you still important and hope in the horizon after when the medical system fell you miserably. Dr. Ikeda very professional and very understanding about your issue. Two tombs up.


    Jim K.

  • My husband and I were immediately impressed with Dr Ikeda. I was hit by a car while cycling which caused broken bones and three brain injuries. The brain injuries caused double vision. Dr. Ikeda examined my eyes and got me started on vision therapy with his occupational therapist who specializes in vision therapy.  She (Chris) is absolutely great.  I am impressed with the array of tools used to help recover my binocular vision.  I am doing things I never thought were possible (balance boards etc).  Chris pushes me and keeps me motivated. I really enjoy my sessions with her.  The office staff is always friendly and they have a wonderful appointment reminder tool that makes it easy to keep my calendar up to date. I am happy the rehab center at Little Co. of Mary recommended them!!


    Teresa S.

  • The Vision Therapy is handled in a separate office through a different door from the shared waiting room. Chris, the vision therapist, has a wide and varied assortment of tools, equipment and resources to best evaluate and treat most vision issues. After just a few visits, my double vision became easier to control, using exercises developed during the therapy process. It was time well-spent.


    Joe M.

  • I have been coming here since I can remember. I love it here. The staff is so amazing and nice. They explain everything they gonna do and never make you feel rushed. Dr. Ikeda has always been my doctor and I would never want another one. He is the doctor for my whole family and is always asking how everyone is doing. I am also so crazy about picking out my frames and have to try so many and each person who helps me take the time and lets me try them all on. I would never want to go anywhere else! I definitely would recommend this office to anyone looking for a great eye doctor.


    Kayla W.

Blog

Lighting-Assessment---Intensity-1

Lighting as Part of A Low Vision Evaluation

A low vision evaluation is in some ways similar to a regular eye exam, and in other ways entirely different. […]

Read More
josh-applegate-p_KJvKVsH14-unsplash

Can ADD/ADHD be a Vision Problem?

According to a study, approximately 20% of 4.5 million children currently identified as having ADHD may have been misdiagnosed. Furthermore […]

Read More
pexels-monstera-6186146

Are all magnifiers the same? The difference in optics between handheld magnifiers

Hand magnifiers are hand-held devices that can be placed over an object or text to enlarge or magnify what you […]

Read More
see all blogs

Contact Us To Amplify Your EyeCare

Working Hours

Monday - Thursday
8:00 am - 5:15pm
friday-sunday
Closed
Location
16816 Clark Ave, Bellflower, CA 90706, United States
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