A developmental perspective on visual word recognition: New evidence and a self-organising model

Abstract

This study investigated the developmental trajectory of two marker effects of visual word recognition, word frequency, and orthographic neighbourhood effects, in French primary school children from Grades 1 to 5. Frequency and neighbourhood size were estimated using a realistic developmental database, which also allowed us to control for the effects of age-of-acquisition. A lexical decision task was used because the focus of this study was orthographic development. The results showed that frequency had clear effects that diminished with development, whereas orthographic neighbourhood had no significant influence at either grade. A self-organising neural network was trained on the realistic developmental corpus. The model successfully simulated the overall pattern found with children, including the absence of neighbourhood size effects. The self-organising neural network outperformed the classic interactive activation model in which frequency effects are simulated in a static way. These results highlight the potentially important role of unsupervised learning for the development of orthographic word forms.

Keywords:

• Orthographic neighbourhood
• Reading acquisition
• Self-organising map
• Word frequency
• Implicit learning

Acknowledgements

The authors thank Marc Brysbaert and two anonymous reviewers for their feedback on an earlier version of this work. The work was supported by Grant No. ANR-06-BLAN-0337 (Agence Nationale de la Recherche, France).

Notes

¹The weighting of bigram activation by empirical letter visibilities was motivated for extended tests of the SOM that are not reported in the present study, and is not critical for the results of the simulations presented here.

²The training regime used in the present simulation study is arguably much closer to the real-life exposure to print of children learning to read, compared with the training regimes that are typically used with backpropagation networks.

³Here we assume that beginning readers perform the lexical decision task as a word identification task—respond “yes” when a word is recognised, and “no” otherwise.