A contingent speech technique in eye movement research on reading

A novel eye-movement-contingent method is presented. It builds on and extends established eye-movement-contingent visual display change methods in that it uses movements of the eyes to control the presentation of acoustic information during sentence reading. In one implementation, an irrelevant spoken word is presented when the eyes cross a predetermined spatial boundary before they move on to a selected visual target word. The relationship between the spoken word and the visual target is manipulated, and the pattern of interference, caused by the presentation of the spoken word, is used to determine the nature and time course of activated representations. Results from three recently completed experiments in which the technique was used show that a word’s phonological code remains active after it has been read and that the activated code has speech-like properties.     

Missing information in spoken word recognition: nonreleased stop consonants.

Cross-modal semantic priming and phoneme monitoring experiments investigated processing of word-final nonreleased stop consonants (e.g., kit may be pronounced /kit/ or /ki/), which are common phonological variants in American English. Both voiced /d/ and voiceless /t/ segments were presented in release and no-release versions. A cross-modal semantic priming task (Experiment 1) showed comparable priming for /d/ and /t/ versions. A second set of stimuli ending in /s/ were presented as intact, missing /s/, or with a mismatching final segment and showed significant but reduced priming for the latter two conditions. Experiment 2 showed that phoneme monitoring reaction time for release and no-release words and onset mismatching stimuli (derived pseudowords) increased as acoustic-phonetic similarity to the intended word decreased. The results suggest that spoken word recognition does not require special mechanisms for processing no-release variants. Rather, the results can be accounted for by means of existing assumptions concerning probabilistic activation that is based on partial activation.     

Processing pronunciation variants: the role of probabilistic knowledge about lexical form and segmental co-occurrence

Two experiments investigated the contribution of lexical knowledge to processing nasal flap variants (e.g. “mental” produced as “mennle”). High and low variant production frequency nasal flap words and nonword counterparts were presented in a “t” detection task. More “t” detections were found in high than low variant frequency nasal flap words; no difference was found in control nasal flap nonwords but control nonwords with a nasal had more “t” detections than nonwords without a nasal. The findings suggest that access to lexical knowledge of an alternative NT pronunciation is modulated by variant frequency of the reduced form and pre-lexical phonotactic knowledge.