Motor vs. Perception – Part One
Here is an excerpt from an email I recently received from a friend who does a lot of advocacy work with children:
I have explained to parents for nearly 3 years that visual deficits fall into two categories: visual motor encompasses strab, amblyopia, vergence, oculomotor, accommodation and teaming, while visual perception is what our brains do with the visual input, including figure ground, visual memory, etc. In a recent conversation with a well-respected VT person, I learned that this isn’t necessarily so. They said the majority of their patients have vergence, strabismus or heterophoria, with some also having oculomotor and accommodation issues, and that the perception issues are a result of the motor deficits. They don’t necessarily treat the perception issues, finding that they usually improve to normal ranges with treatment of the motor issues. I had thought that all diagnosed areas were mutually exclusive, and not necessarily based one on the other. It makes perfect sense that the perception is affected by the input, I just hadn’t thought about it this way. As I try to better understand, I would appreciate your input?
Let’s start by answering the question with one simple word: Yes.
Everything affects everything.
To help make things easier to understand, there are times when it’s necessary to split out visual components. Accommodation is accommodation, vergence is vergence, spatial awareness is spatial awareness, and visual discrimination is…well, you get the idea. From our side of the desk, it’s easy to get caught up in defining each activity and understanding which specific skill we’re after, which is good – and bad. We need to remember, though, that these challenges don’t exist in a bubble. Poor motor skills can lead to poor perception skills, in the same way poor perception skills can dampen motor skills. Conversely, improving motor skills can improve perception because of symbiotic relationship between the two systems.
Clear as mud, right?
Let me explain.
When we work accommodation, we don’t do so in a vacuum. There are always other factors in play – vergence, for example – even if your patient is patched. Just because one eye is patched doesn’t mean it isn’t doing something. Want proof? Try clearing a -6.00 lens monocularly in a “lens on/lens off” activity for two full minutes and see which eye “feels it” more. Most times it’ll be the patched eye for a variety of reasons. Take the same activity and consider the demands on spatial awareness. How far away is that plane of regard which we’re trying to focus on? How close is the near plane? Poor spatial awareness can be both the root of the problem and/or a symptom. Either way, improving accommodation should, to some degree, improve spatial awareness. One of the most powerful lines I’ve ever come up with in working accommodative activities is suggesting patients “be aware of the changes in space” when working accommodation. This applies to lenses, N/F Rock activities, monocular pushups, and just about every level of Wachs Mental Minus. We’re using accommodation to improve spatial awareness, and we’re using spatial awareness to improve accommodation. The same principle applies to vergence and a patient’s awareness of SILO and/or SOLI, which is a true integration of both vergence and spatial awareness.
Starting to make sense?
Now try working things the other way. Are there times that perception changes motor? Definitely. Consider a straight Hart Chart saccadic activity. Is spatial awareness important in knowing where that next letter is? Are visual discrimination and visual memory important in knowing what the next letter is? Isn’t part of perception’s job telling your eyes where to go and what to look for?
I hope you answered yes.
Let that marinate. More to come!