How do roots and suffixes influence reading of pseudowords: A study of young Italian readers with and without dyslexia

Abstract

The study explored the different influences of roots and suffixes in reading aloud morphemic pseudowords (e.g., vetr-ezza, “glass-ness”). Previous work on adults showed a facilitating effect of both roots and suffixes on naming times. In the present study, pseudoword stimuli including roots and suffixes in different combinations were administered to sixth-grade children with dyslexia (N=22) and skilled readers (N=44), matched for chronological age. Indeed, the sequential reading strategy of less proficient readers (particularly for pseudowords) should favour the emergence of differences between left and right constituents (root and suffix, respectively) in reading performance. Results showed that for both children with dyslexia and skilled young readers the onset of pronunciation depended exclusively on roots, while there was no significant effect of suffixes. However, both roots and suffixes led to higher levels of accuracy than matched orthographic strings of letters. Posthoc regression analyses confirmed the morphological nature of the root and suffix effects, over and above the effects of the frequency of their orthographic patterns. Results indicate that the position of the reading units within the letter string, as well as their differential effects on latencies and accuracy, should be taken into account by models of morphological processing in word recognition and reading and by applied intervention research.

Keywords:

• Morphological structure
• Reading processing
• Children with dyslexia
• Pseudowords

Acknowledgements

The research reported in this paper was supported by MIUR-PRIN Grant 2005111248 to Pierluigi Zoccolotti. The authors thank Dr Roberto Iozzino for making possible to examine children at the Centre for Cognitive and Linguistic Disorders (ASL 1) in Rome.