The Development of Spelling-Sound Relationships in a Model of Phonological Reading

Developmental aspects of the spelling to sound mapping for English monosyllabic words are investigated with a simple two-layer network model using a simple, general learning rule. The model is trained on both regularly and irregularly spelled words, but extracts the regular spelling to sound relationships which it can apply to new words, and which cause it to regularise irregular words. These relationships are shown to include single letter to phoneme mappings as well as mappings involving larger units such as multiletter graphemes and onset-rime structures. The development of these mappings as a function of training is analysed and compared with relevant developmental data. We also show that the two-layer model can generalise after very little training, in comparison to a three-layer network. This ability relies on the fact that orthography and phonology can make direct contact with each other, and its importance for self-teaching is emphasised.