Visual information processing and visual skills

What is visual information processing?

An excellent explanation comes from a 1996 study from the field of rehabilitation medicine published in the journal NeuroRehabilitation by Raymond et al.  The authors provide a good summary explanation of visual processing and its component parts (visual cognition, visual memory, pattern recognition, scanning, visual attention).  The study authors state:

"There are a large number of identifiable visual processing skills operating within the visual   system, and there have been several attempts to describe them in some kid of rational framework.  These include the Deficit Skill Approach which categorizes visual processing into specific deficits, and the Information Processing Models, which describe the reception organization and assimilation of visual information on a continuum from simple to complex.  An example of the latter is found in the work of Warren who appears to have provided the best approach towards understanding visual processing.  In her model, each skill level is dependent upon the skill level below it, and relies on the following functions: including visual cognition, visual memory, pattern recognition, scanning and visual attention.  These functions can be described as follows:

Visual cognition: The ability to mentally manipulate visual information and integrate it with other sensory information to solve problems, formulate plans and make decisions.  It includes the ability to analyze similarities and differences, to understand the relationship of stimulus elements to one another, and to reason and deduce about the nature of visual stimuli.  It also includes the ability to use contextual cues to help in the development of meaning from the image.

Visual memory:  The ability to visually process stimuli, store them in memory and retrieve them upon command.  The individual must also be able to match what they see with what is stored in memory.

Pattern recognition: The ability to identify the salient features of an object including configural and holistic aspects such a shape, contour, and general features, such as color, details, shading, and texture.  It is important for the individual to be able to recognize objects even when viewed from different or obscure angles (perceptual constancy).

Scanning:  The ability to record all details of a scene systematically in an organized and thorough manner.  The route taken is known as the scan path.  The eyes obtain and process information by executing a series of broad sweeping cycles with reexamination of the most important details several times to ensure identification.  These eye movements are called saccades.  Saccadic eye movements are normally executed in an organized, systematic, and efficient pattern.

Visual attention:  The ability to attend to stimuli and shift attention between stimuli.  Vision therapy for visual attention deficits have been shown to improve reading comprehension in children by 220% and increase overall attention in the classroom.  Visual attention is also implicated in the development of dyslexia.

 

How are visual information processing deficits treated?


Perhaps the best illustration of vision therapy in the treatment of visual processing disorders comes in patients with brain injuries, as the presence of an injured brain makes treatment more challenging.

Vision therapy or training has been shown to successfully treat visual processing deficits even in the presence of brain injuries. Raymond et al. provide a summary, at page 237, of studies taken from neurological, optometric and occupational therapeutic literature showing the effect of visual processing therapy and training on visual processing deficits.


Who is qualified to assess visual information processing disorders?


A study in the journal NeuroRehabilitation recommends that the assessment of visual processing should be done by an optometrist – not an ophthalmologist. The ophthalmologist, according to the authors, does not have the expertise to make the assessment. The study authors note that patients:

should be referred to a behavioral or neuro-optometrist. It was also noted that referrals made to an ophthalmologist may be insufficient, as they are primarily concerned with the health of the eye only, and ophthalmologists are mostly experienced with acute medical problems rather than rehabilitation issues. This assertion is supported by considering the typical components of an ophthalmologic exam, which may yield a lack of specificity, and/or provide information which is inadequately defined in terms of rehabilitation consequence. Trobe, Acosta, Kirscher and Trick identify a lack of measurement in areas of distance and near acuities, contrast sensitivity and confrontation, while Gianutsos and Matheson describe a need for greater quantification in terms of field gradations and boundaries, and binocularity conditions. A more thorough investigation is important for the rehabilitative efforts of all patients who demonstrate visual processing deficits.

The study's authors go on to note that "[o]phthalmologists are excellent surgeons and expert at treating acute disease but their expertise does not to extend to the diagnosis or treatment of visual processing deficits."


Do visual information processing deficits impact academic performance?

According to several studies, the answer is, "yes".

One example is a 2005 study by Goldstand et al. published in The American Journal of Occupational Therapy entitled "Vision, Visual-Information Processing, and Academic Performance Among Seventh-Grade Schoolchildren: A More Significant Relationship Than We Thought?"

The researchers (consisting of professors of optometry and occupational therapy), set out to compare visual and visual-information processing skills between children with and without mild reading and academic problems and examine the incidence of visual deficits among them. They found that visual function significantly distinguishes between children with and without mild academic problems, as well as on visual-perception scores.

Another study published in Optometry & Vision Science in 2002 by Kulup et al. found that poor visual memory (one component of visual information processing) as significantly related to below-average reading decoding, math, and overall academic achievement (as measured by the Stanford Achievement Test) in second- through fourth-grade children, while controlling for age and verbal ability.


Reading comprehension: vision therapy for visual attention deficits improves reading comprehension by 220%

A study of sixth grade students with below average reading scores found that providing visual attention therapy can significantly improve their attention and reading comprehension.  Visual attention is one component of a group of skills related to visual information processing - the way the brain takes in and makes sense of the images received by the eye.

The developmental optometrists at our Vancouver eye clinic have witnessed this improvement first hand.  Kids who hate reading, can't do it very well and read a below grade level have improved following therapy to become kids who love reading and often can read at above grade level!

The study was published in the November/December 2003 Journal of Learning Disabilities.  The study's authors found that as few as 12 one-hour sessions of vision therapy can enhance reading ability and improve a child's overall attention in the classroom.

Dr. Harold A. Solan, O.D., M.A., FCOVD, Distinguished Service Professor of Optometry at the State College of Optometry, State University of New York and lead researcher for the study said this about the results:

Results of this study support previous research that found visual attention and eye movement abilities contribute significantly to a child's ability to read.  This newest research confirms that visual attention can be improved through vision therapy resulting in enhanced reading comprehension.  Far too often, children with reading and learning difficulties may struggle in school because of undetected vision problems.  Difficulties with maintaining visual attention and processing visual information in the classroom doom many children to reading failure. Results of this and other studies now confirm the significance of good visual abilities to reading and learning. Vision abilities needed to succeed in school can be developed through programs of vision therapy which can lead to improvements in reading and learning as found in our study.

The children who were the subject of the study were tested before and after vision therapy using standardized measures of attention processing.  One group of kids received vision therapy and a second group did not.  The vision therapy group showed significant gains in attention scores and reading comprehension. In terms of learning rate, these students reading skills progressed 1.1 years or 220%.

Visual attention therapy procedures, a part of optometric vision therapy services, have for a long time been used in treating patients with learning-related vision problems. According to Dr. Sloan, 

This study further confirms the benefits of vision therapy that developmental optometrists have clinically reported in their patients for many years. Vision therapy, a prescribed program of visually guided procedures or 'exercises', is used to help the eyes work together and with the brain to properly interpret visual information.


 

 

 

Vision therapy and adults with convegence insufficiency

Patients "should be referred to a behavioral or neuro-optometrist. It was also noted that referrals made to an ophthalmologist may be insufficient, as they are primarily concerned with the health of the eye only, and ophthalmologists are mostly experienced with acute medical problems rather than rehabilitation issues. "

Raymond et al. Rehabilitation of visual processing deficits following brain injury.NeuroRehabilitation 6 (19960 229-240.

 

Vision therapy for visual attention deficits improces reading comprehension

"Results of this study support previous research that found visual attention and eye movement abilities contribute significantly to a child's ability to read.  This newest research confirms that visual attention can be improved through vision therapy resulting in enhanced reading comprehension. "

 

Neuroscientist (and adult vision therapy success story) Dr. Susan Barry gives a TED Talk about depth perception and vision therapy: