Orthographic Mapping and Dyslexia

What is Orthographic Mapping?

Educators use the term “orthographic mapping” to describe the way that written words are etched into long-term memory. Once a person has “mapped” a word, they will be able to recognize the word instantly by sight, without needing to decode or rely on conscious thought processes. A “mapped” word can also usually be easily retrieved from memory, so that it can be written and spelled correctly. All skilled readers develop an extensive mental reservoir of known words; this mental word bank is essential for reading fluency. Capable adult readers are estimated to have mental libraries of 30,000 to 70,000 words stored this way.

But for dyslexics, this process is not so easy. Difficulty acquiring this mental word bank is at the heart of dysfluent and labored reading. When dyslexic readers cannot recognize words automatically and instantaneously, they must use other strategies to decipher words, such as phonetic decoding or predictive strategies, which are slower and more error-prone. When more time and effort is required to figure out each word, the ability to comprehend the text is diminished. The person often loses track of the words and must go back to re-read sentences or passages. The process of reading becomes exhausting.

However, dyslexic children and adults can and do develop strong sight vocabularies and improved reading skills — the key is that they need a different set of tools to get there than typically developing, capable readers. Unfortunately, traditional approaches to tutoring often leave these needs unmet. Many tutors mistakenly believe that dyslexic readers can follow the same sequence of transitioning from phonetic decoding to automatic word recognition as non-dyslexic learners, given enough time or repetition. But a struggling dyslexic child usually has difficulties that are outside and beyond problems with phonetic decoding or memory.

The Importance of Visual Processing

Different typefaces make letter identification harder.

In order to add a word to the automatic word bank, the brain must do much more than simply connect a sequence of letters to their sounds. The reader must be able to accurately and automatically recognize each letter, despite significant variations in fonts, as well as differences in the appearance of upper and lower case letters. For example, they must be able to easily see the difference between a lowercase l and upper case I. The reader must be able to quickly and easily distinguish between similar-appearing letters — such as b and d, or c and e.

This is not simply a matter of memory, but is tied to the way the brain sorts and categorizes information. For dyslexics, the brain simply offers up more possibilities for each symbol.

The reader must also be able to correctly register the sequence and order of letters, and retain that letter order in memory, along with the appropriate directionality of the letters and lines of text.

These visual processing skills seem natural to adult readers, but they are not skills that are required in contexts other than reading. Thus, these skills are developed only through the process of learning to read and practice. Most children who have these skills will progress quickly from the decoding stage of reading to building a basic sight vocabulary. When dyslexic children struggle, it is often because of a problem with the integration of these visual skills. This is not a problem with eyesight, but rather with the way the brain perceives, categorizes, and interprets the symbols on the page.

Understanding Word Meaning

Orthographic mapping also requires the brain to connect the letter sequences contained within words to the meaning of each word. This is true in all written languages, but especially important in English, because the English spelling system is dictated largely by word meaning. For example, the words reign, rain, and rein each sound the same (/rān/), but they have different derivations and meanings — and none follows the more conventional English spelling pattern seen in words such as cane, sane, and pane.

Word meaning is a particularly important mental hook for dyslexic readers. This is not simply a concern tied to novel or complex words. Dyslexic readers will also stumble over short, familiar function words like for, if, so, or by. These words have abstract and ambiguous meanings. They don’t have a clear meaning when standing on their own, and they tend to signify different things in different contexts. While a dyslexic reader will usually be able to recognize these words in print (they are not difficult to decode), they will often hesitate and stumble, or even substitute other words (such as from or it) because of confusion over meaning. They will also often have difficulty remembering the differences in spelling between these words and their homophones such as four or buy – again because although the words are easily decodable, the meaning hasn’t been mentally imprinted.

Of course, many of the small common words of English are also phonetically abstruse, such as are, would, know, and any. For those words, the meaning hook is even more important.

to, meaning “in the direction of”

When the meaning piece is missing or confusing, dyslexic readers are unable to map these words to memory. The word to is as simple as can be, but what is a “to”? what does it mean? The dictionary gives at least thirteen different definitions. Adding to the confusion, the word sounds just like two and too, but means something different. So rather than being mapped for automatic recognition, it stays in a sort of mental limbo, needing to be figured out anew each time it is encountered.

To make matters worse, when dyslexic readers are confused about word meaning, their ability to correctly perceive the print on the page often goes awry as well. This is a result of disorientation, which is the brain’s way of trying to make sense of confusing information by rearranging it. This can cause misperceptions such as letters shifted out of order or reversed, or seeming to be moving about on the page.

Where Educators Go Wrong

As long as the right elements are in place — accurate perception of the letter sequence, understanding of meaning, and an ability to relate the pronunciation of the word to the letters — the word can be mapped and stored in permanent, automatic memory. This is not tied to a specific type or order of instruction. Children who have successfully learned to read through whole-word teaching approaches will end up with the same instant recognition as children who have successfully learned to read through systematic phonics instruction.1

But more is needed for the children who are not succeeding. Unfortunately, educators often assume that the problem lies with the child’s memory, rather than considering other barriers or missing elements that are preventing the child from being able to mentally assemble and lock down the word. A teacher might assume that the child needs more exposure to sight words in isolation, and encourage sustained and repetitive practice with flashcards. Another teacher might focus on phonetic rules and encourage practice with decoding nonsense words or reading books with easily decodable text. Many teachers mistakenly believe that dyslexic children simply need to see or decode the word more often in order for it to be imprinted in their minds.

But these efforts can often simply create more confusion for the child, making it even more difficult to achieve the goal of automatic word recognition. A person cannot form a permanent memory of a word if their visual perception of the letters and letter sequence is not consistent, or if they are unable to understand the meaning of the word. In this setting, repetition will only add to the confusion, and make retention of information more difficult. For example, a child may not understand that then and than are two separate words with different meanings, or may have difficulty distinguishing from and form, The confusion may arise from the similar appearance of the words, from a tendency to transpose letters, from difficulty in hearing in the difference in the pronunciation of the words, or from not understanding the distinct meanings of the words — or it could be a combination of these factors. Whatever it is, the misperception or misunderstanding needs to be addressed and resolved before the brain can retain an accurate representation of the word.

A Simple Solution

Image adapted from www.freepik.com

Fortunately, many of these barriers can be easily addressed once recognized. It simply requires awareness of these elements and a willingness to implement appropriate strategies to address them. Ideally, early reading instruction should integrate simple strategies which include focusing on the orthographic (visual) and semantic (meaning) elements of words along with the phonological. For example, the simple strategy of encouraging children to orally spell out the letters of new words encountered in print will help build solid left-to-right visual scanning skills.2 Researchers have demonstrated improved reading among dyslexic children with as little as ten minutes of visual-attention training.3 Experimental research has also shown that struggling readers have better recall of newly-taught words when they were given word meanings than when they were given pronunciation alone.4 Schools that have implemented the Davis Learning Strategies at the primary level have seen dramatic improvements in reading outcomes among their students, because this program supplements regular reading instruction with specifically-developed tools to address these visual and meaning-based these skills.5

The mental processes involved in reading come together like a complex piece of machinery, with many moving parts. When everything is in place, reading can be smooth and efficient. But a problem with any single part, no matter how small, can cause a breakdown in the whole system. The key to success lies in being able to understand all the parts, and having the insight and tools needed to directly address specific problems that different children may encounter along the way.

A version of this article was previously published in September 2020. This article has been edited and supplemented with additional references.


  1. Studies show that children who have had explicit instruction in phonics end up reading more slowly than children taught with more balanced approaches. Thompson, G.B., McKay, M.F., Fletcher-Flinn, C.M. et al. Do children who acquire word reading without explicit phonics employ compensatory learning? Issues of phonological recoding, lexical orthography, and fluency. Read Writ 21, 505 (2008)
  2. Marshall, A. Brain Function, Spell-Reading, and Sweep-Sweep-Spell (2005)
  3. Caldani, S.; Gerard, C.-L.; Peyre, H.; Bucci, M.P. Visual Attentional Training Improves Reading Capabilities in Children with Dyslexia: An Eye Tracker Study During a Reading Task. Brain Sci. 2020, 10, 558
  4. Taha, H. How semantic knowledge enhances word recognition? New evidence from struggling readers performances. Applied Neuropsychology: Child (2022)
  5. Severinsen, Jane. Davis Learning Strategies in New Zealand Schools Action Research Inquiry (2018)