dyslexia and cognitive psychology

Sean Weigold Ferguson

Cognitive Psychology

Rollins College

Dyslexia

“Accurate and fluent word reading and/or spelling develops very incompletely or with great difficulty”

Affects between 5% and 17% of the population

Overview

(McCandliss and Noble, 2003)

Types

Developmental: Begins in childhood and usually

continues throughout adulthood

Acquired: Often from traumatic brain damage

Impaired Processes

Phonological reading:Words in isolation

Phonological coding:Recalling confusing strings of phonemes

Lexical access: Retrieving phonemes from long-term memory

Working memory: Remembering strings of phonemes that are sometimes confusing.

Symptoms

Reading and spelling: Omissions Substitutions Inversions Additions

Often accompanied by dysfunction in: Fine motor coordination Visual discrimination Auditory segmenting difficulty

(Cicchetti and Cohen, 2006)

Diagnosis

Reading and spelling skills significantly below performance expectations for age, intelligence, and education level (1.5 to 2 standard deviations).

However, IQ may be inaccurately measured in dyslexics.

(Cicchetti & Cohen, 2006; McCandliss & Noble, 2003)

Implications

Affects between 15 and 50 million Americans.

Culture places high value on reading.

Scholastic success often dependent on reading skills.

Many skilled jobs require employees to be literate.

(McCandliss and Noble, 2003)

Theories

Environmental: Interventions can be effective

Biological: Abnormalities in chromosomes 3, 6,

and 15

(Paracchini, Scerri, and Monaco 2007)

Neuropsychology

Dysfunction in:Left perisylvian area involving the superior

temporal gyrus; involved in phonological processing.

Leads to underdevelopment of: Left occipito-temporal extrastriate visual system

near the middle portion of the fusiform gyrus; involved in automatic processing of visual word form perception in skilled adult readers.

(McCandliss and Noble, 2003)

Surrounding Structures

I created this figure using an image by the University of Western Ontario Psychology Department

Specific Structures

Original image from McCandliss and Noble, (2003)

What is it Like?

Video by Coventry University TV

Questions?

Sean Weigold FergusonSWeigold@Rollins.edu

407-584-7326

This presentation is available online at www.SlideShare.net/SeanWF

It is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License

References

Cicchetti, D., & Cohen, D. J. (2006). Developmental psychopathology. John Wiley and Sons.

McCandliss, B. D., & Noble, K. G. (2003). The development of reading impairment: A cognitive neuroscience model. Mental Retardation and Developmental Disabilities Research Reviews, 9(3), 196-205.

Paracchini, S., Scerri, T., & Monaco, A. P. (2007). The genetic lexicon of dyslexia. Annual Review of Genomes and Human Genetics, 8, 57-79.

University of Western Ontario Psychology Department (2005). Temporal lobe sulci [Photograph], Retrieved April 24, 2010, from: http://psychology.uwo.ca/fmri4newbies/Images/temporal_lobe_sulci.jpg