Understanding Disorders of Reading

three main areas of the left hemisphere involved in reading-related tasks

• inferior frontal gyrus

• temporoparietal area including posterior temporal cortex, angular gyrus, and suprmarginal gyrus

• occipitotemporal area including fusiform gyrus and inferior temporal gyrus

the inferior frontal gyrus is involved in

semantic tasks- vocabulary and working memory

the temporoparietal area is involved in

integrating what is seen and heard- sound symbol association

the occipitotemporal area is involved in

orthographic processing tasks- word recognition

acquired reading disorders

• occur after a period of normal development

• can occur as a result of TBI, stroke, or other brain trauma to areas of the brain that control reading

specific learning disability

• part of IDEA, 2004

• a disorder in one or more of the basic psychological processes involved in understanding or using language, spoken or written, that may manifest itself in an imperfect ability to listen, think, speak, write, spell, or do mathematical calculations

• does not include children who have learning problems that are primarily the result of:

  • visual

  • hearing

  • motor abilities

  • intellectual disabilities

  • emotional disturbance

  • environmental, cultural, or economic disadvantage

specific learning disorder

• used as part of the DSM-V diagnosis

• a neurodevelopmental disorder of biological origin manifested in learning difficulty and problems in acquiring academic skills markedly below age level and manifested in the early school years, lasting for at least 6 months; not attributed to intellectual disabilities, devleopmental disorders, or neurological or motor disorders

• specify if:

  • with impairment in reading, in written expression, or in mathematics

(developmental) dyslexia

• affects a person beginning in childhood and makes learning to read and developing reading skills difficult

• language based neurobiological disorder that causes marked impairments in the development of basic reading and spelling skills

• manifests in difficulties with:

  • word-level reading skills

  • decoding

  • encoding

dyslexia has great variability in terms of

manifestation and severity

how is intelligence with individuals with dyslexia?

relatively normal

neurobiological basis of dyslexia: structure

• there is no definitive brain marker that are the conclusive causes

• likely due to structural deficits in two areas:

  • phonological representation

  • rapid naming

phonological represetation- dyslexia

• tasks that are considered alphabetic principles

• understanding that a spoken word can be segmented into phonemes and blending them together through writing

• phonemic awareness is the best example of this

• very strong predictor of later reading abilities

• located in the frontal lobe- inferior and superior frontal gyrus- damage associated with difficulties

rapid naming- dyslexia

• 2nd strongest predictor of later reading abilites

• how quickly you can name something represented in a picutre, identify colors, numbers, letters, words, etc.

• areas involved- left angular gyrus, supramarginal gyrus, posterior supertemporal gyrus

• a structural problem in these areas are associated with problems with rapid naming

neurological basis of dyslexia: function

• studies found differences in brain function during reading tasks

  • reduced brain activity in the left hemisphere

  • overactivation of the left inferior frontal gyrus

  • greater activation in the right frontal and temporal lobes

  • more activation of the middle and superior temporal gyri compared to typically developing peers

prevalence data for learning disability (LD)

• 13-14% of the school population qualifies for special education under some category

• of that percent, 6-7% of children have

• 85% of children with this disability likely have problems with reading and language processing

prevalence data of dyslexia

• 5-10% of school age children

• some data goes up to 20%

core deficits seen in individuals with dyslexia

• difficulty with word recognition

• difficulty with reading fluency

• difficulty with spelling tasks

• complex language skill difficulties

common problems seen in children with dyslexia

• problems with spoken language and listening comprehension

• negatively impacts self-image, academics, social-emotional functioning, and vocational skills

• problems learning to speak

• learning letters and their sounds

• organizaing written and spoken language

• memorizing number facts

• reading quickly enough to comprehend

• persisting with and comprehending longer reading assignments

• spellling difficulties

• learning a foreign language

• correclty doing math operations

screenings for dyslexia

• DIBELS

• AIMSWEB

screening data identifies students at risk for

failing to achieve content standards

student receives interventions through

RTI- response to intervention

if the child doesn’t respond to RTI they are

referred for a comprehensive evaluation

a comprehensive evaluation includes testing in areas of:

• intellectual

• academic achievement

• receptive and expressive language

• phonological awareness

three major predictors of dyslexia

• phonological processing (phonemic awareness)

• alphabet recognition

• rapid automatic naming

assessments of phonological processing

• comprehensive test of phonological processing- (CTOPP-2)

• The phonologicall awareness test-2- (PAT-NU:2)

assessments/ tools for alphabet recognition

• sound symbol associations and letter naming

• the phonological awareness test-2 (PAT-NU:2)

• informal measures

assessments/ tools for rapid automatic naming

• rapid automatized naming rapid alternating stimulus- (RAN-RAS)

• comprehensive test of phonological processing (CTOPP-2)

to determine signs and symptoms of dyslexia

review case history data related to the family history and early development

• look for reports of reading or spelling difficulties across generations in the family

• determine if there was normal prenatal and birth history

• identify delays or difficulties acquiring speech-language skills

signs and symptoms of dyslexia

• difficulty with rhyming, blending sounds, learning the alphabet, linking letters with sounds

• difficulty learning rules for spelling

• difficulty remembering “little” sight words that can’t be sounded out (the, of, said)

• compare listening comprehension with reading comprehension

• look for signs of a reluctant reader

• identify slow, word by word reading

• identify very poor spelling

• look for non flueny writing

• tendency to mispronounce words when speaking

• determine vocab weaknesses

a poor reader may initially appear to fit the profile of dyslexia but

if that learner responds quickly to appropriate intevention, the source of the reading problem is more likely related to poor instruction