Phonological Core Deficits and Reading Difficulties

A phonological core deficit makes it difficult to learn the sounds making up the words in a language.

The deficit can make it difficult to learn to speak and can make it harder to correctly pronounce words in the language a child is learning. A phonological core deficit makes it difficult for children to discriminate between closely related sounds such as those formed by the letters “b” and “p.” Not being to hear close distinctions may delay speech learning and may create a situation where the child cannot hear the mispronunciation he or she is making.

Example conversation for a child with articulation disorders:

Parent: What is this?
Child: A phish.
Parent: No, fish!
Child: That is what I said, phish!!

Difficulties with sound capture also have major impacts on learning to read.  When children begin to learn letter sounds they often make a very important discovery—the sounds that letters make map onto the sounds contained in spoken words.  Researcher call this discovery “the alphabetic principle,” meaning that the child realizes that the individual sounds that letters make can be combined to form the words used when speaking.

A skill that develops after letter sounds are learned is the ability to manipulate the sounds that letters make. For example, a child develops the ability to sound out letters and to then rapidly blend those sounds so that he or she can recognize the word. Children also develop the ability to identify words by adding or deleting letters. This is called “phonological awareness.” A child who has phonological awareness can tell if two words rhyme, or what the word “cat” would sound like if the letter “s” was added at the beginning of the word.

The ability to learn letter names, the sounds of letters and the ability to manipulate those sounds using phonological awareness skills are important precursors to learning to read.  Difficulties in learning these skills are important predictors of reading difficulties. Children who develop dyslexia often display an insensitivity to rhyme as contained in nursery rhymes, they are slow at learning letter names and letter sounds, and they have difficulty acquiring the skills that underlie phonological awareness. These difficulties can all be traced back to the phonological core deficit that was probably present at birth.

Genetics and Gender with Phonological Core Deficits

Phonological core deficits, and hence dyslexia, probably has a biological basis that is genetic in origin. Reading difficulties tend to run in families, most often on the father’s side of the family.  Moreover, there appears to be sex differences in dyslexia with 3 out of 4 of formally diagnosed dyslexics being male.