Semantic-context effects on word recognition: Influence of varying the proportion of items presented in an appropriate context.

Several recent experiments have shown that an appropriate semantic context facilitates word recognition. Lexical (word/nonword) decisions about a word such as "nurse" are faster when it follows a related word such as "doctor". The present experiment examines the consequence of varying the proportion of semantically related adjacent words. The effect of semantic context is found to depend on the overall proportion of related word pairs. More facilitation occurs when there is a greater proportion of related word pairs. This finding contradicts theories of word recognition which account for context effects solely by postulating transient increases in the aecessibility of only those words semantically related to the particular preceding stimuli encountered by the observer. An adequate theory must include an account of strategic or adaptive processes in which the past usefulness of contextual information modulates its influence in the word recognition process.