Processing Speed, Phonological Awareness, and Reading in Developmental Dyslexia

1
Processing Speed, Phonological Awareness, and
Reading in Developmental Dyslexia Heeyoung
Park, Sunjung Kim, Jungjun Park, Linda J.
Lombardino Communication Sciences and Disorders,
University of Florida

• Stepwise Regression Controlling for Age and
  Thinking Ability

• Purpose
• To examine the predictive contributions of
  processing speed (PS) and phonological
• awareness (PA) to single word reading and
  connected text reading in younger and older
• groups of children with developmental dyslexia
• Hypotheses
• PS will be a better predictor of word-level
  reading and text-level reading than PA for
• readers with dyslexia. Specifically
• 1. In the younger group, both PS and PA will make
  significant contributions to reading.
• 2. In the older group, PS will contribute more
  variance to the prediction of reading than PA.
• Findings
• Older dyslexic children (10-15 years) performed
  more poorly on standardized cognitive
• and reading tests than younger children (6-8
  years). The visual matching test of
• processing speed showed the most significant
  difference between the two groups. In
• stepwise regression analyses controlling the
  effects of age and thinking ability, younger
• children showed that both elision and visual
  matching were significant predictors of
• word and text reading. Older children showed
  rapid naming was a significant predictor
• of word and text reading. When rapid naming was
  excluded from predictor variables, the
• visual matching made unique contribution to word
  reading.
• Interpretation

Elision r².14 Visual Matching r².09
Elision r².13
Visual Matching r².19
Timed Word Reading
Untimed Word Reading
Timed Text Reading

• Younger Group deficit (1SD below the mean) in
  timed text reading task
• Older Group deficits in PS, and timed word
  text reading tasks
• Older dyslexic children performed more poorly on
  all tests than younger children (VM the largest
  decrease, t2.90, p.005).

• Participants
• Younger Group 6 to 8 years old dyslexic children
  (N20, mean age of 7.9)
• Older Group 10 to 15 years old dyslexic children
  (N35, mean age of 12.5)
• Measures
• (1) thinking ability (WJ-III-COG), (2) processing
  speed (WJ-III-COG visual matching,
• CTOPP rapid naming), (3) phonological awareness
  (CTOPP elision, blending words),
• (4) single word reading (TOWRE sight word
  efficiency, WJ-II-ACH letter-word
• identification), (5) connected text reading
  (GORT Fluency)
• Comparative Data

• Partial Correlation Controlling for Age and
  Thinking Ability

• VM was correlated significantly with RAN across
  age groups.
• (younger group, r.48, plt.05 older group,
  r.50, plt.01)
• Word reading was correlated significantly with
  text reading.
• (younger group timed word, r.55, plt.02
  untimed word, r.65, plt.005)
• (older group timed word, r.47, plt.01
  untimed word, r.40, plt.03)
• Timed and untimed word reading were not
  significantly correlated in the younger group,
  but were strongly correlated in the older group
  (r.80,plt.0001).

Rapid Naming r².47
Rapid Naming r².29
Rapid Naming r².09
Timed Word Reading
Untimed Word Reading
Timed Text Reading

• The contribution of cognitive factors associated
  with PS and PA was related to age. PS was
  significantly more depressed in the older
  dyslexic children.
• Rapid naming was more strongly related to word
  and text reading than phonological knowledge in
  school age children (Kail, Hall, Caskey, 1999
  Katzir et al., 2006 Wolf et al., 2002),
  especially in older children.
• Evaluations of young children, who are showing
  signs of emergent literacy difficulties, should
  examine both processing speed and phonological
  knowledge. Visual matching may be a good task for
  assessing PS in preschool children who have not
  yet developed automatized naming skills.
• Findings support the importance of exploring
  clinical approaches to determine the efficacy of
  increasing PS at the earliest stages of reading
  instruction.

• Processing speed (PS) and phonological awareness
  (PA) are key cognitive factors that characterize
  dyslexia. In the younger readers, both PS and PA
  contributed unique variance to reading. In the
  older readers, only PS contributed unique
  variance to reading.
• PS, as measured by visual matching, was a
  better predictor of reading for younger dyslexic
  children.
• PS, as measured by rapid naming, was a better
  measure of reading for older dyslexic children.
• PS was a good predictor of both timed and untimed
  word reading.
• When rapid naming was not used as a predictor
  variable, visual matching, a nonlinguistic task
  of PS, was a better predictor of word reading
  than PA in older children, in spite of their weak
  elision skills.

Plt.05