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“b, d, p, q” Letter Reversals – An Indicator of Visual Information Processing Deficits?

Does your child often mistake the letters “b” for “d” or “p” for “q”? These mistakes,

known as letter reversal errors, oftentimes cause parents to be concerned, for these errors can potentially impact their child’s ability to effectively read, write, and learn. When parents first find their child frequently making letter reversals, they oftentimes wonder if these reversals are normal, if they indicate dyslexia, or if something else is at play. This blog post further delves into the visual impact of letter reversals and its indication of deficits in visual information processing.

My child is constantly reversing letters…Are they dyslexic?

Letter reversals do not automatically signify that your child is dyslexic. Studies have

investigated if there is a predilection for letter reversals in children with dyslexia and have found mixed results. Some studies have found that letter reversals occur at higher frequencies in children with dyslexia [1-3] , while other studies have found little to no significance difference in the frequency of letter reversals between non-dyslexic and dyslexic children [4] . Letter reversals are common in early childhood when children are first learning to read and write and should cause concern if they persist later in life.

Will my child ever stop reversing letters?

Prior to entering school, children inherently learn in life that an object is still the same

object even if its spatial orientation is changed. In other words, a chair is still a chair regardless of the chair being turned left, right, or upside down. It is when children are first introduced to reading and writing that they learn of the significant impact spatial orientation has on letters in reading and writing. For example, the “b” that makes a “buh” sound is different from the “d” that makes the “duh” sound even though the “d” looks like a flipped over “b”. As a child continues to develop, they begin to internalize this understanding of the impact of spatial orientation on linguistic symbols. Typically, letter reversals become less frequent as a child develops and begins to internalize this understanding of the impact of spatial orientation on linguistic symbols like letters. However, if these letter reversals persist past the age of 8 years (i.e. the end of second grade), it may be an early indicator of a more complex issue—a visual information processing deficit or deficits.

What is visual information processing?

Visual information processing refers to the brain’s ability to interpret and make sense of

what is seen through our eyes and then integrate this information with other senses and higher cognitive functions. There are three main categories of visual information processing skills that can be further subdivided into smaller component skills. The three main categories of visual information processing skills are visual spatial skills, visual integration skills, and visual analysis skills. Visual spatial skills refer to the ability to organize the external visual space (i.e. the items we see around us) by understanding directional concepts and spatial relationships. For instance, a child will be able to identify left and right on their own body as well as being able to identify left and right on other people or objects. Visual integration skills refer to the ability to integrate visual information with other motor and perceptual processes. Examples of visual integration skills include being able to accurately copy a written passage as well as being able to correctly identify a visual pattern after hearing the pattern being tapped out loud. Visual analysis skills refer to the ability to interpret, recognize, recall, and manipulate visual information. Some examples of visual analysis skills include being able to identify an object based on its distinctive features (e.g. shape, orientation, size, color) as well as being able to discriminate between it and

other objects, being able to recall visual information that was previously presented, being able to mentally recall a visual image (e.g. imaging what a “p” looks like),and being able to imagine what something could be despite only given some of the visual information (e.g. knowing dashed lines in the form of a square forms a square).

What type of visual information processes do letter reversal indicate?

Letter reversals may indicate deficiencies in a child’s visual spatial and visual analysis

skills. More specifically, it may indicate deficiencies in sub-component skills of laterality and

visual discrimination. Laterality refers to the ability to accurately identify the left and right of

objects. In the case of letter reversals, a child with poor laterality skills may make letter reversals because he or she has trouble determining if “b’s” or “d’s” are curved on the left or right side. Visual discrimination refers to one’s ability to identify an object based on its distinctive features (e.g. shape, orientation, size, color) as well as able to discriminate between it and other objects. For example, a child with poor visual discrimination may have difficulty identifying a “b” as having a long line at the top left whereas a “p” has a long line at the bottom left.

How are visual information processing deficits identified and treated?

A vision therapist or optometrist can perform an assessment of your child’s visual

information processing skills if a visual information processing deficit is suspected. While there are several methods to assess visual information processing skills, the assessments are typically standardized tests that correlate findings with age-matched norms. A couple examples of these assessments include the Test of Visual Perceptual Skills (TVPS) and the Jordan Right-Left Reversal Test, which can be seen in Figures 1 and 2 respectively. The TVPS assesses a group of visual analysis skills, whereas the Jordan Right-Left Reversal Test assess visual spatial skills (i.e. more so the ability to identify the left and right of objects or other people, referred to as laterality). Once a child’s deficits in visual information processing skills are identified, a vision therapist can tailor specific vision therapy activities that are customized to build upon and enhance the child’s visual information processing skills.

Figure 1: Example of the discrimination subtest on the TVPS in which the patient must identify which numbered target is the exact same as the target shown above. Image obtained from:

Figure 2: Example of the Jordan Right-Left Reversal Test. Image obtained from:

Written by:

Brittany Mohning

Chicago College of Optometry | Class of 2024


1. Wolff PH, Melngailis I. Reversing letters and reading transformed text in dyslexia: A

reassessment. Reading and Writing. 1996;8(4):341-355. doi:10.1007/bf00395113 

2. Terepocki M, Kruk RS, Willows DM. The incidence and nature of letter orientation

errors in reading disability. J Learn Disabil. 2002;35(3):214-233.


3. Brooks AD, Berninger VW, Abbott RD. Letter naming and letter writing reversals in

children with dyslexia: momentary inefficiency in the phonological and orthographic

loops of working memory. Dev Neuropsychol. 2011;36(7):847-868.


4. Grosser GS, Trzeciak GM. Durations of recognition for single letters, with and without

visual masking, by dyslexics and normal readers. Percept Mot Skills. 1981;53(3):991-

995. doi:10.2466/pms.1981.53.3.991

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