The role of semantics in reading and spelling: evidence for the 'summationhypothesis'

This study documents a patient, SA, with an impairment of semantic memory a rising as a result of Semantic Dementia (Pick's disease). The patient is im paired at deriving semantic knowledge from both words and pictures. However , his ability to derive semantic knowledge of countries is relatively spare d compared to concrete nouns and famous people. The presence of a semantic deficit was used to investigate the role of semantics in reading and spelli ng. Several novel cueing/priming paradigms are reported which suggest that SA is able to use partial semantic knowledge to constrain his reading and s pelling. These results are broadly consistent with the 'summation hypothesi s' [27] and suggest that normal reading and spelling may take place by inte grating both semantic information and knowledge of direct orthography-phono logy correspondences. (C) 2000 Elsevier Science Ltd. All rights reserved.