Motor Learning in the Motor City – Part 2


vorIn Part 1 we re-visited Albert Darwin Ruedemann, Jr., M.D., who founded the Kresge Eye Institute at Wayne State University College of Medicine in Detroit, Michigan in the 1940s.  Dr. Ruedemann’s concepts make it very clear that binocular coordination is a learned concept, an underpinning of optometric vision therapy that is all but lost in contemporary ophthalmology.  Ironically a re-awakening of this awareness may occur at the Kresge, but more likely through its Department of Otolaryngology rather than its Department of Ophthalmology.  I suggest this because of the work of W. Michael King, Ph.D., Director of the Vestibular and Oculomotor Laboratory at the Kresge Hearing Research Institute in Detroit.

HelmholtzRecognize this man?  Bonus points if you do, but to most he’s a name much more than a face and your only clue is that he is credited for the invention of both ophthalmoscopy and ophthalmometry.  That’s right – he’s Hermann Ludwig Ferdinand von Helmholtz, M.D., and applying his insights to vision may hold the key to understanding why so many of the patients we see are under-served by Helmholtz’s 21st century contemporaries.  I suggest this because of a letter to Nature co-authored by Dr. King prior to his arrival at Kresge in which he wrote:

“Binocular coordination of eye movements is essential for stereopsis (depth perception) and to prevent double vision. More than a century ago, Hering and Helmholtz debated the neural basis of binocular coordination. Helmholtz  believed that each eye is controlled independently and that binocular coordination is learned. Hering believed that both eyes are innervated by common command signals that yoke the eye movements (Hering’s law of equal innervation). Here we provide evidence that Hering’s law is unlikely to be correct.”

 

Helmholtz Hypothesis

The figure above, illustrating the essential difference between Hering and Helmholtz’s theories, is from a gorgeous 2010 Ph.D. Thesis at the Aerospace Medical Research Unit of McGill University, so in a way it might be conceived as rocket science. It supports King’s point that a possible cause of strabismus is a failure of the eye movement system to develop appropriate binocular coordination mechanisms during infancy, while the cortex is maturing and motor learning between the two eyes and the rest of the body is maturing.

I’ll have more to say in Part 3 about re-discovering Helmholtzian understanding of binocular vision as a learned, coordination process, but in the interim don’t forget the motor city …

6 thoughts on “Motor Learning in the Motor City – Part 2

  1. What would prevent the eye movement system from developing appropriate binocular coordination mechanisms during infancy? Is it possible that as some farsighted or anisometropic kids (with stereoscopy or at least some) grow and visual demands increase, binocular coordination disintegrates? The idea of binocular vision as a learned coordination process is reassuring to me. My now four-year-old daughter Stella is now having unreliable binocular vision. It goes out a lot when she gets tired beginning in the afternoon or after a challenging activity like gymnastics. I’m glad to be aware of it–if I didn’t know this was going on, I may just perceive her as a difficult child and react differently, bringing enhancing the difficulty I perceived. Sad thought.

    • Amber, I’m so sorry to read Stella’s binocular vision is becoming less stable. I know Sue Barry had a similar experience, and has since resumed some VT exercises in a daily regimen … Perhaps immersing Stella in those binocular experiences that delight her would be a way to strengthen those hard-fought visual pathways? Also Dr. Press has blogged about VT enhancing games on the iPad which sound fun to me, anyway … Any other thoughts about binocular vision maintenance?

  2. Precisely, Amber. It’s quite a different school of thought that the state of binocularity can be an index of visual behavior and learned processes rather than a structural defect in muscle function. That was the essence of what Dr. Ruedemann was imploring his surgical colleagues: we can alter the muscle by cutting and re-locating it’s insertion into the eyeball, but it’s the motor learning that will influence how the brain is able to utilize both eyes in conjunction. Stella’s eye may drift out when her cognitive resources in combining the two eyes are depleted.

  3. Thank you, Dr. Press. Do you have thoughts on what causes the typical binocular coordination to fail to develop (or should i say, to be learned, as it is a learned skill) in infancy?

  4. I never cease to be amazed at the “new” published clinically relevant insights that come from neuroscience, like you mentioned above in the 2010 Ph. D. thesis at the Aerospace Medical Research Unit at McGill University, that supports many of the techniques that we are currently using in office-based optometric vision therapy. More important, I look forward to you expanding these insights presented in this Blog series into ways to develop even better therapeutic methods. To offer one example of a technique that follows the proprioceptive and visual feedback elements of what you describe, readers can check out this photo on our Facebook page: https://www.facebook.com/wowvisiontherapy?ref=sgm#!/photo.php?fbid=10151221752530963&set=a.411005180962.184516.185119320962&type=1&theater

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