The role of lexical co-occurrence in aphasic sentence production

Abstract

ABSTRACTThis study explores the notion that learned associations based on lexical co-occurrence probability influence sentence planning and, consequently, may contribute to the ability of aphasic speakers to produce well-formed sentences. To encourage aphasic speakers to rely on such associations, the subjects were administered a sentence generation task in which an uninflected transitive verb was the sole basis for sentence planning. Performance by normal control speakers was used to identify verb-noun pairs reflecting some degree of lexical association. The aphasic subjects tended to use proportionately fewer associated word pairs in their sentences. The level of associate use was not correlated with either their picture naming scores or their performance on a test of semantic judgment. Finally, despite the aphasic subjects' below normal production of associated word pairs on sentence generation, when nouns associated with the target verbs were included in the sentences, performance was less anomalous for each subject. These findings are used to explore how a network of lexical associates might facilitate sentence processing.