Longitudinal study of reading and writing rehabilitation using a bigraph-biphone correspondence approach

Background: Treatments for sound-blending ability in phonological dyslexia that train single grapheme-phoneme correspondences have had mixed success. A more recent approach to re-establishing sound-blending abilities is to train correspondences of bigraph-biphone units (CV + VC = CVC) (Berndt, Haendiges, Mitchum & Wayland, 1996; Friedman & Lott, 2002). This approach has proved beneficial thus far, although the reasons for its success are not yet fully understood. Aims: The purpose of this longitudinal investigation was to use the bigraph-biphone segment-blending approach to improve both reading and writing abilities in an individual with phonological dyslexia/dysgraphia. Re-establishing this ability laid the foundation for continued treatment with longer words and phrases. Methods & Procedures: A case study design combining reading and writing treatment was used in three treatment protocols. Initially, treatment focused on improving the participant's awareness of bigraph-biphone correspondences and sound-blending abilities for one-syllable nonwords. The successful completion of this protocol was followed by two treatments to extend these abilities to reading and writing two-syllable words and eventually phrase-length material. Outcomes & Results: Gains were made in all treatment protocols. The participant progressed from an inability to read one-syllable nonwords to reading and writing phrase-length material. Conclusions: This study provides further evidence that using bigraph-biphone correspondences to train sound-blending abilities can improve both reading and writing abilities in cases of phonological dyslexia. Furthermore, the success of this treatment programme illustrates the benefit of a targeted treatment programme even 5 years post onset of aphasia, for reading and writing rehabilitation.