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Lexical or whole-word reading

Competent reading essentially involves the whole-word or lexical process of reading which ensures fluent reading and a “direct” access to meaning. It recognizes the shape of the word and immediately find its sound correspondence in memory (or phonological), the meaning of the word being evoked, which is the ultimate goal of reading.

The whole-word process (or eidetic = photographic), both more automatic and faster, can even bypass the phonological pathway, which is more controlled and slower. Most of the time, the expert reader would not need to use his phonological knowledge to recognize written words. The observation of a double dissociation between visual and phonological dyslexia in patients with brain damage is an argument in favor of the neuropsychological existence of the two independent procedures for the recognition of written words (Coltheart, Masterson, Byng, Prior & Riddoch, 1983; Funnell, 1983; Shelton & Weinrich, 1997). Numerous studies supporting these models have also emphasized the optional phonological code while reading (Peereman, 1991, for a review).

Coltheart M, Masterson J, Byng S, Prior M, Riddoch J. Surface dyslexia. Q J Exp Psychol A. 1983 Aug;35(Pt 3):469-95.

Funnell E. Phonological processes in reading: new evidence from acquired dyslexia. Br J Psychol. 1983 May;74 (Pt 2):159-80.                     

Weinrich M, Shelton JR, McCall D, Cox DM. Generalization from single sentence to multisentence production in severely aphasic patients. Brain Lang. 1997 Jun 15;58(2):327-52.

Peereman R. Phonological assembly in reading: lexical contribution leads to violation of graphophonological rules. Mem Cognit. 1991 Nov;19(6):568-78.

When the child becomes able to recognize a word as a unit, he gradually builds his orthographic lexicon. The operation of this lexicon is not yet fully known, but it seems to be like a dictionary which exists in our brain, allowing rapid identification (the faster the more familiar word) and immediate access to meaning.

This procedure then develops to become more and efficient as reading becomes more competent. Ultimately, the adult reader would only use the “photographic” procedure, which is obviously much faster than going through words syllable by syllable (which remains necessary when we must read for example, new or meaningless words or of a foreign language).

http://www.coridys.asso.fr/pages/base_doc/txt_habib/entree.html

Imagine a child who reads the following sentence:

The locomotive arrives at the station

versus

The-lo-co-mo-ti-ve-ar-ri-ves-at-the-sta-tion“.

(or syllable by syllable)

 

Surface_01_en

In the first case, the child immediately recognizes the words and understands what he reads. In the second case, the child does not read words but syllables one by one. Difficult to quickly understand what is read.

Surface_02_en

Surface dyslexia

Surface dyslexia, in its pure form, is characterized by a selective impairment of reading irregular words while reading regular words and pseudo-words is relatively preserved. This selective difficulty reading irregular words translates a dysfunctionnal lexical reading procedure.

These children do not present associated disorders of oral language and have good capabilities in short term verbal and workong memory and have good phonological awareness. They also have difficulties in visual processing that make comparing sequences of letters or identify targets among others.

It is said that pure forms of surface dyslexia are relatively rare in clinical practice. But I can assure you that in my optometric practice, these children are much more numerous than the statistics show.

Visuo-attentional dyslexia

There is also, according to some authors, another form of dyslexia, called “visual-attentional” where the child has a good memory of the spelling of words and is able to transcribe sounds into words. For cons, the type of errors encountered in this disorder is reversals in groups of letters, omissions, additions, approximate reformulations, skippng lines while they read.  line breaks. The child may confuse letters and words with others closely resembling it. It would be a disorder affecting necessary attention for an effcient reading activity.

(In : http://www.ac-grenoble.fr/ia73/spip/IMG/pdf/dys_apedys.pdf)

These children also have oculomotor (eye movement) and visual discrimination problems, difficulties in visual attention, difficulties in copying material from a book or the blackboard.

It is difficult to conceive a child who has a serious visuo-attentional problem would not show a form of surface dyslexia. There is certainly a very close relationship between the two since both can prevent the establishment of a proper orthographic lexicon. They may also be different manifestations of the same problem called “visual dyslexia”. This close relationship between visual and attentional problems is reinforced by the significant progress in reading and spelling seen in a child with surface dyslexia following a trainign program focused on visual processing capabilities (Launay and Valdois , 1999)

Valdois S, Launay L. Évaluation et rééducation cognitives des dyslexies développementales: illustration à partir d’une étude de cas.  In : La rééducation neuropsychologie : Études de cas. AZOUVI P, PERRIER D, VAN DER LINDEN M (eds). Marseille, Solcoll, 1999 : 95-116).

 Visual-perceptual skills essential to insure adequate whole-word reading

It is probably unnecessary to say that the best readers are those who read in a whole-word fashion, this  method of reading is fast and understanding is also much better. But what is the action to take if a child uses no or has a poor orthographic lexicon? We must ensure that the related visual and perceptual skills are adequate. Otherwise, visual training will be needed to improve these skills.

What are the skills that have a close relationship with the development of orthographic lexicon? First, eye movements: reading requires a constant movement of the eyes along a line of text, which is done by a series of short jumps (saccades) interspersed with longer breaks during which takes place all intake of visual information. These jumps between fixations are very short, about one-thirtieth of a second. Saccades take approximately 250 to 300ms. Saccades are also an index of visual attention. We have tests that evaluate the speed, accuracy and fluency of reading. Eye movement problems hamper efficient learning and reading quality (failure to follow the text, loss of place, jump words or lines, etc.). For reading to be effective, eye movements must be flexible, fast and accurate.

Then visual attention and concentration allow the child to remain focused and attentive to every detail of what we see and as long as necessary. Attention and concentration are a preqequisite to good visual discrimination. In addition, visual attention is the link between perception (making information available) and cognition (use this information). It ensures maximum reception all the information from our visual environment. Visual concentration promotes maximum use of working memory to collect, store, retrieve and process the relevant information. It facilitates the work and especially the intellectual performance.

Short-term and sequential visual memories allow the child to recognize an item after a brief exposure, or to recall items in the same order and in the same sequence. For example, remembering the order of letters in a word or words in a sentence with a quicker understanding of what is read. Children who show difficulties in visual sequential memory may have difficulties copying information from the board or a book, to learn to read mulriple words or sentences and remember what they read. They may also have difficulties in creating their orthographic lexicon, which affects fluency and reading comprehension.

Visualization or mental imagery is the ability to create images of a word, a sentence or a paragraph in our head (our mental picture). This ensures good understanding of what is read and allows a better organization of information, making it easier to retain and build an efficient orthographic lexicon. This perceptual skill is also essential for mental arithmetic and spelling of words. If a child reads a story without being able to mentally see the scene described in the text, then this will influence contextual

In summary, the eyes must move effectively to ensure high quality of visual information, and the child must be able to remain attentive and focused on what he reads. Visual memory will also allow to recognize the same words in a text. Many children can not build a orthographic lexicon because they can not even recognize a word they just read and read again a few lines later. Visualization allows the child to “juggle with words” in his head. And finally, it is practicing reading every day that ensures efficiency in reading. More often we see the same words, the faster they will be included in the orthographic lexicon.

Conclusion

According to scientific research, three basic skills (among others) will thus directly influence reading performance in children: visual memory, visual attention and visualization. The best readers are capable of recognizing whole words easily (eidetic, global or whole-word reading). This accelerates visual decoding, requires less energy and promotes better understanding. Reading phonologically (syllable by syllable) slows down the reading process and does not guarantee an adequate understanding of a text. The best readers need not phonological awareness to read and can recognize most words without having to dissect them. That is why we have developed a particular portion of our vision therapy to enhance these perceptual abilities. We try to develop better whole-word reading to improve reading efficiency and comprehension.

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