Effects of the semantic context on the processing of careful and casual speech.

Listeners need contextual information to recognize the highly reduced word pronunciation variants that frequently occur in casual speech. Especially, semantically related words preceding them may be informative. It is unclear, however, whether listeners also benefit from preceding semantically related words when these are reduced as well, which is typically the case in casual speech. The present study reports two experiments examining how semantic priming modulates the semantic and phonological processing of target words in both carefully and casually articulated sentences. In a word repetition experiment, listeners were presented with carefully and casually articulated sentences with sentence-medial prime words and repeated the sentence-final words. This experiment did not show any effects of semantic priming. In a lexical decision experiment, participants made lexical decisions about the sentence-final words when presented with the same sentences. This experiment showed similar and significant semantic priming for the carefully and casually articulated sentences. These results strongly suggest that, also in everyday speech, preceding semantically related words facilitate the lexical-semantic processing of casually pronounced words. The higher cognitive load necessary for the processing of casually pronounced words may be substantially reduced by listeners' expectations of the words to come, based on the casually or carefully pronounced semantic context.