Visual Pathways and Classroom Instruction
Early Choice Pediatric Therapy has found that once a child enters school, about 75% of the classroom activities are directed through visual pathways. The majority of students who have problems with their vision system, upwards of 90%, are never diagnosed.
According to the National Vision Research Institute of Australia, about 40% of the human brain is involved in one form or another with visual perception. Upon visual input, visual signals leave the eye and follow a path into the superior colliculus in the brainstem, where the electrical impulses react and control all eye movements such as blinking, dilating pupils, and tracking objects that are moving or tracking a line of words. The optic nerve then forms synapses and sends neurons to the occipital lobe of the cerebral cortex. This pathway is responsible for experiencing and controlling visual perception. The input comes from both eyes, the right cortex receiving impulses from the left orbit and the left cortex receiving input from the right orbit.
Once the input reaches the cortex, it must be processed with the neural networks. Non-verbal visual information and verbal information both need to be processed. This includes orthographic information. Patterns need to be distinguished.
Multiple processes of the vision system work together for visual perception and discrimination of orthography and output (George McClosky, Ph.D, 2007). The sound-symbol connection is extremely important for successful reading. According to Berninger and Richards, sound codes in speech play an important, even fundamental role in the recoding of visual stimuli into language using the orthographic word form representations.
Executive Function, Memory Systems, and Visual Perception
Additionally, executive function does play a part in this process, as well as visual, auditory, and muscle memory. Background knowledge of both general and specific nature in both content and language goes hand-in-hand with reading and gaining meaning from what one reads (comprehension). The ability to decode and encode words that are familiar, unfamiliar, or nonsense words and filter and sort them into usable meaning brings comprehension.
It is also important to note that Rayner, in 1997, summarized 25 years of research on eye movements. Reading obviously involves eye movements, which are called saccades, when the eyes are moving rapidly. The rapid eye movements and tracking are separated by fixations when the eyes are relatively still. Saccade movements typically travel about 6 to 9 letter spaces; they are not impacted by the size of print. The complete perceptual span is larger, extending to 14 or 15 letter spaces to the right and 3 to 4 spaces to the left. It is the saccade movement to the left combined with the perceptual span length that assures that every letter of every word enters the visual field.
Understanding this visual span perception span combination leads us to realize that efficient readers do this easily. About 10-15% of the time, readers also shift back (known as regression) to look back at material that has already been read. And as text becomes more difficult, saccade length tends to decrease and regression frequency increases.
It is important to note that the space between words does facilitate fluent reading. When spacing between words varies or is not available, reading is slowed by as much as 50%. The research further notes that efficient eye movement is more critical than generating predictions of upcoming words. Readers systematically move their eyes from left to right across the text and then fixate on most of the content words. The processing associated with each word is very rapid, and the link between the eyes and the mind is very tight. Rayner, K. (1997) Scientific Studies of Reading, 1(4) pages 317-339.
How Vision Develops
Vision and visual perception develop in an ordered manner and they improve over time. Each principle or skill has a continuum. Additionally, each has a range of responses from very basic to complex. A child can respond at any point on each skill continuum and can be at different points at any given time on each continuum.
Brain Based Learning, (1997) author Eric Jensen, states that up to 87% of students do NOT learn from hearing alone. He goes on to state that we under-utilize our visual perception system when learning. Use of colored handouts, charts, graphs, photographs, posters, and graphic organizers such as those incorporated into Bonnie Terry Learning products will increase student’s learning through boosting and strengthening use of the visual system. Using visual and kinesthetic methods increase student performance and decrease discipline problems.
Reading and Vision Therapy Intervention Studies
McKane F, et al. A comparison of auditory / language therapy with school visual support procedures in a public school setting. Journal of Optometric Vision Development 32 (2): 83-92, 2001.
Some hold that poor reading eye movements are caused by poor language skills and if the auditory/ language skills were improved that reading and eye movements during reading would also improve. Twenty-nine third grade children who had previously been identified as being below average in some academic area were the subjects of this study. The experimental group contained 18 subjects, equally distributed between genders. After screening evaluations, all children were enrolled in an auditory/language enrichment program and the experimental group also received school-based vision techniques which were individually programmed and administered by school personnel, in the school setting daily for 30 minutes a day for 3.5 months. Both groups improved significantly over pre-test scores on the reading aspect of the WRAT and reading rate with comprehension as measured by the –Visagraph. The experimental group also demonstrated a significant improvement in reading eye movements as measured by the Visagraph, but the control group did not. The authors concluded that both visual and auditory/language intervention has a positive effect on the reading WRAT scores as well as the reading rate with comprehension. Reading eye movements, however, were significantly improved only with visual intervention and not with auditory/language therapy.
Summary of Research on the Efficacy of Vision Therapy for Specific Visual Dysfunctions
by Jeffrey Cooper, M.S., O.D.
Professor of Clinical Optometry State University of New York, State College of Optometry
Reading Problems
Atzmon, et al.,37 addressed the effectiveness of orthoptics/vision therapy in the area of reading disabilities in an article, which appeared in Binocular Vision and Eye Muscle Surgery Quarterly, an ophthalmological journal. This double-blind prospective study compared the effectiveness of orthoptics to other treatment modalities in the remediation of reading disorders. These investigators matched three groups of children with reading disabilities. One group received orthoptic treatment to improve fusional amplitudes to at least 60D (prism diopters). Group two received conventional reading tutoring. Group three received no treatment and served as the control. Each child had 40 20-minute sessions of therapy. Prior to therapy 100% had poor fusional convergence by the authors’ criteria, 60% had a receded near point of convergence, and many had asthenopic symptoms. After treatment asthenopic symptoms were eliminated in the orthoptic group. Reading had improved significantly in both the orthoptic/vision therapy group and
reading group, but not in the control group. Atzmon, et al.,37 concluded that orthoptics/vision therapy was as effective as reading tutoring but had an additional benefit of eliminating asthenopia. This study also meets the criteria of multi-subject, controlled study.
http://www.add-adhd.org/pdfs/03_sum_vt_research_Cooper.pdf
When you combine visual processing activities with intervention results magnify.
Sample of Activities/Resources That Address Visual Processing
- Visually tracking objects without moving the head.
- Catching objects in space, e.g. bean bags or balls.
- Coloring “in the lines,” copying activities.
- Visual tracking of letters or words with a built-in scoring (accountability) system.
- Visual memory activities
- Visual discrimination activities
- Eye-aiming activities
- Visual figure-ground activities like hidden pictures
- Visual language activities that build vocabulary
- Play marbles, jacks, and other eye-hand skill games
- Awaken the Scholar Within: Visual, Auditory, and Kinesthetic (VAK) Therapy Program, which addresses all 9 areas of visual processing
- ASW Reading, Writing, Study Skills Program, which addresses 7 areas of visual processing
- Five Minutes to Better Reading Skills reading fluency program, which addresses 5 areas of visual processing
