The temporal unfolding of local acoustic information and sentence context.

The purpose of this study was to investigate the temporal unfolding of local acoustic information and sentence context using both cross-modal interference (CMI) and word-monitoring tasks. The timing of sentence context effects have important theoretical implications for models of language processing (e.g., initial context independence vs. initial interaction). Yet, different tasks tend to yield different results. For both experiments, stimuli from an acoustically manipulated "goat-to-coat" continuum were embedded in sentences whose interpretation was biased toward either "goat" or "coat." In experiment 1 (CMI), the primary task was listening to sentences for comprehension; the interference task was a word/nonword decision to an unrelated visual probe that appeared at one of three positions within the sentence. Results showed immediate effects of the acoustic manipulation, but only delayed effects of sentence context. These results were interpreted to indicate that phonological processing is initially context-independent but is followed by rapid context integration. Experiment 2 used a word-monitoring task: Response times were significantly longer when sentence context was incongruent with the monitoring target, showing an immediate effect of context. The apparently contradictory results of the two experiments together support an account of language processing in which phoneme categorization is initially independent of sentence context unless an explicit judgment about the identity of the target is required.