"Difficulties in reading can be caused by many conditions outside reading ability, such as poor motivation or not being exposed to a literate environment at home and in the community," writes noted educationist J P Das in "Reading Difficulties And Dyslexia: An Interpretation for Teachers."

The book is sort of a ready reckoner on dyslexia for not only teachers and parents but also for professionals concerned with learning disabilities.

For the school psychologist, the book is an interpretation that gives pre-eminence to the PASS (Planning-Attention-Simultaneous-Successive) theory of cognitive processes – the four major processes that replace traditional views of IQ and redefine intelligence.

The book, published by Sage, provides a selective review of the existing knowledge in the field and tries to demystify the continuing enigma of dyslexia, a slight disorder of the brain that causes difficulty in reading and spelling but does not affect intelligence.

Dyslexia was the subject of the Aamir Khan film "Taare Zameen Par" where the actor instils confidence in young Ishaan (Darsheel Safary), who is literally snubbed by his teachers and parents for his low marks and cheeky behaviour.

According to Das, an Emeritus Professor of Educational Psychology at the University of Alberta in Canada, the reading problems of some children can be caused by difficulties in comprehension.

"A slow rate of reading is a sign of reading difficulty, especially when children can code phonologically but have a slow reading speech. In phonetically regular languages such as German, Spanish and Portuguese, or the classical languages like Latin and Sanskrit, any new word can be read but the speech of reading is unusually slow among dyslexics. A child's word – decoding and comprehension skills are distinct abilities and should be tested separately," he writes.

Das feels there is a need for phonological coding among children so that they can learn to read.

"The learning of rhymes and alliterations that occur spontaneously during childhood prepares the child for reading and spelling. However, what seems to be a good predictor of reading is phonemic awareness, that is, the child’s ability to break words down into phonemes, to manipulate beginning and end sounds, and to be able to say the sounds when some phonemes are eliminated," the book says.

According to the author, IQ does not predict dyslexia. "Many children at all levels of IQ fail to learn to read adequately in spite of getting the same instruction in the classroom as their classmates. That some children with a normal IQ of 100 or better do not learn to read is evidence enough for saying that IQ is not very relevant when explaining or predicting reading disability," he says.

The author feels the cognitive processes that may be lacking for learning to read must be recognised first.

"Tasks and situations that promote the use of the cognitive strategies must be designed carefully so that they provide a structure for the discovery of strategies to occur.