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 [email protected]
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
Top Related