Comparison of phonological and whole-word treatments for two contrasting cases of developmental dyslexia

Abstract

This study compared the effectiveness of two reading treatment programmes for two contrasting developmental dyslexics. W.B. demonstrated “pure” phonological dyslexia (deficient nonword reading but normal irregular-word reading) and N.S. “pure” surface dyslexia (the converse pattern). Both participants completed: (a) a phonological programme, which targeted the sublexical reading procedure through repeated exposure to word “families” with the same grapheme–phoneme correspondence (GPC; e.g., frail, raid, bait); and (b) a whole-word programme, which targeted the lexical reading procedure through tasks that emphasize whole-word visual analysis (e.g., speeded identification of visually degraded words). Both participants improved after training on the targeted words and/or GPCs. However, W.B. demonstrated reliable generalization only following the phonological programme and only in his reading of nonwords. In contrast, N.S. showed generalization across all types of word materials following both programmes. Although the whole-word programme (in particular the degraded-images technique) resulted in numerically greater improvement for N.S., this difference was not significant. Practical and theoretical implications of these results are discussed.

Keywords:

• Developmental dyslexia
• Dual route model
• Surface dyslexia
• Phonological dyslexia
• Treatment.

Acknowledgments

The research reported here was conducted while the first author was a doctoral student at the School of Psychology, Victoria University of Wellington. Dr. Rowse's research received financial assistance from a Victoria University PhD Scholarship and a Port Nicholson Rotary Club Goalsetter Award. Dr. Rowse also wishes to thank Victoria University Disability Support Services for assistance and support during the research. We are grateful to the participants N.S. and W.B. and their families and to the Principal and staff of Naenae Intermediate School, for their involvement and support. Finally, we thank Dr Richard Siegert for his helpful feedback and advice at various stages of the project. A portion of the data reported in this paper was presented at the 32nd Australasian Experimental Psychology Conference, Melbourne, 1–3 April 2005.

Notes

¹ Rather more controversially, Whitney and Cornelissen (2005) propose that this inability to perform single-saccade position coding is caused by insufficient development of internal grapho-phonological representations.

² These individuals were poor at reading across the board (both real words and nonwords), which was interpreted as indicating a significant prelexical reading problem.

³ Laxon, Masterson, Gallagher, and Pay (2002) examined reading latencies for monosyllabic words in a group of 16 nine–ten-year-olds with average reading ages and obtained mean latencies of 1,108 ms for high-frequency and 1,264 ms for low-frequency words.

⁴ Ratio scores for normal adults (reported in the test manual) range from 1.0 to 1.1 across all three item types, and for normal 6-year-olds ratio scores for line drawings range from 1.12 to 1.25 (from Joy & Brunsdon, 2002).

⁵ Here and elsewhere, the values reported are parameter values associated with that predictor based on a simultaneous logistic regression analysis. In all analyses involving comparison of pre- and posttraining performance, word identity was incorporated as a repeated measure, and the analysis was run using generalized estimating equations (parameter values reported are Type III score statistics based on empirical standard error estimates).