The terms visual perception and visual processing are often used interchangeably, and refer to the brain’s ability to understand what is seen.
Sensation is the pickup of information by our sensory receptors, for example the eyes, ears, skin, nostrils, and tongue. In hearing, sensation occurs as waves of pulsating air are collected by the outer ear and transmitted through the bones of the middle ear to the cochlear nerve. In vision, sensation occurs as rays of light are collected by the two eyes and focused on the retina.
Perception is concerned with the interpretation of what is sensed. The physical events transmitted to the retina may be interpreted as a particular color, pattern, matching shape, letter, number and face — these are all examples of how visual perception is used in everyday life.
What is a visual perception deficit?
A visual perception deficit or visual processing disorder refers to a reduced ability to make sense of information taken in through the eyes, and should be distinguished from the types of visual deficits that are most commonly associated with the blind and partially sighted, that is, deficits in visual acuity. The latter defects are caused by improper functioning of the sensory organ itself — the eye — due to malformation, injury, or disease. The visual processing problems addressed within the field of learning disabilities are concerned with problems that occur despite the fact that the child has structurally sound eyes and adequate muscular control over them.
Children with visual perception problems have trouble recognizing, remembering, and organizing visual images as needed to understand written and pictorial symbols. This can interfere with many aspects of daily living, most notably learning to read, write, and learn math. Recent studies have indicated that visual perception deficits may play an important role in either dyslexia or dyscalculia. Some studies have reported visual perception deficits as important components of dyslexia (Goswami et al., 2010; Stefanics et al., 2011; Vidyasagar & Pammer, 2010; Zhao et al., 2014). In contrast, other researchers have identified visual perception deficits associate with dyscalculia (Sigmundsson et al., 2010; Zhou & Cheng, 2015).
Below are examples of visual perception skills and how deficits can interfere with learning:
Visual perceptual skills
- Foreground-background differentiation: The particular letter, or word, or sentence, that the reader is focused on is elevated to the level of foreground, whereas everything else within the field of vision of the reader (the rest of the page and the book, the desk on which the book is resting, the section of the floor and/or wall that is visible, etc.) is relegated to the background. In math, figure-ground problems may cause difficulties in keeping individual problems separate from each other. The student may lose his place on a worksheet, confuse problem numbers with digits in the problem itself, or not finish the problem, etc.
- Form discrimination: Whether it be the differentiation of the shape of a circle from a square, or the letter B from P, the ability to perceive the shapes of objects and pictures is an important skill for the developing child to acquire. There is hardly an academic activity that does not require the child to engage in form discrimination.
The most obvious classroom activity requiring the child to discriminate forms is that of reading. The learning of the letters of the alphabet, syllables, and words will undoubtedly be impeded if there is difficulty in perceiving the form of the letters, syllables, and words. That the discrimination of letters is a crucial skill in the early stages of reading is evidenced by an extensive literature review conducted by Chall. She concluded that the letter knowledge of young children is a better predictor of early reading ability than the various tests of intelligence and language ability.
- Size discrimination: Capital letters, being used at the start of a sentence, sometimes look exactly the same as their lowercase counterparts, and must therefore be discriminated mainly with regard to size. A person who is unable to interpret size may, for example, find it difficult to distinguish between a capital letter C and a lowercase c.
- Spatial relations: This refers to the position of objects in space. It also refers to the ability to accurately perceive objects in space with reference to other objects. A person with a spatial problem may find it difficult to distinguish letters like b, d, p, and q.
- Synthesis and analysis: Synthesis refers to the ability to perceive individual parts as a whole, while analysis refers to perceiving the whole in its individual parts. Synthesis plays an important role in reading, while analysis is of special importance in spelling.
- Visual closure: Difficulties in visual closure can be seen in such school activities as when the young child is asked to identify, or complete a drawing of, a human face. This difficulty can be so extreme that even a single missing facial feature (a nose, eye, mouth) could render the face unrecognizable by the child.
- Visual memory: Visual memory is often considered to be a subset of visual perception rather than a separate skill. Visual memory involves the ability to store and retrieve previously experienced visual sensations and perceptions when the stimuli that originally evoked them, are no longer present. Various researchers have stated that as much as eighty percent of all learning takes place through the eye – with visual memory existing as a crucial aspect of learning.
Overcoming deficits in visual perception
Interpretation of sensory phenomena can only be done on the basis of past experiences of the same, similar or related phenomena. Perceptual ability, therefore, heavily depends upon the amount of perceptual practice and experience that the subject has already enjoyed. Of course, lack of experience may cause a person to misinterpret what he has seen. In other words, perception represents our apprehension of a present situation in terms of our past experiences, or, as stated by the philosopher Immanuel Kant (1724-1804): “We see things not as they are but as we are.”
Edublox programs are effective in overcoming reading and other learning difficulties by addressing the underlying shortcomings that interfere with academic performance. Underlying shortcomings include visual perception.
Goswami, U., Wang, H. L. S., Cruz, A., Fosker, T., Mead, N., & Huss, M. (2010). Language-universal sensory deficits in
developmental dyslexia: English, Spanish, and Chinese. Journal of Cognitive Neuroscience, 23, 325–337.
Sigmundsson, H., Anholt, S. K., & Talcott, J. B. (2010). Are poor mathematics skills associated with visual deficits in
temporal processing? Neuroscience Letters, 469, 248–250.
Stefanics, G., Fosker, T., Huss, M., Mead, N., Szucs, D., & Goswami, U. (2011). Auditory sensory deficits in
developmental dyslexia: A longitudinal ERP study. Neuroimage, 57, 723–732.
Vidyasagar, T. R., & Pammer, K. (2010). Dyslexia: A deficit in visuo-spatial attention, not in phonological processing.
Trends in Cognitive Sciences, 14, 57–63.
Zhao, J., Qian, Y., Bi, H. Y., & Coltheart, M. (2014). The visual magnocellular-dorsal dysfunction in Chinese children
with developmental dyslexia impedes Chinese character recognition. Scientific Reports, 4, 7068.
Zhou, X., & Cheng, D. (2015). When and why numerosity processing is associated with developmental dyscalculia. In
Chinn, S. The routledge international handbook of dyscalculia and mathematical (pp. 78–89). Swales & Willis Ltd,
Exeter, Devon, UK: Routledge.