Prosody affects visual perception in polysyllabic words: Evidence from a letter search task.

Previous research has shown that phonology influences the visual perception of a word's letters. However, the influence of prosody, including word stress, on grapheme perception in polysyllabic words is poorly investigated. The present study addresses this issue with a letter search task. Participants searched for vowel letters (Experiment 1) and consonant letters (Experiment 2) in stressed and unstressed syllables of bisyllabic words. Results reveal facilitated vowel letter detection in stressed syllables compared with unstressed syllables, indicating that prosodic information affects visual letter perception. Moreover, an analysis of the response time distribution revealed that the effect was present even for the fastest decisions but increased for slower response times. However, no systematic stress effect emerged for consonants. We discuss possible sources and dynamics of the observed pattern and the importance to accommodate feedback processes of prosody on letter perception in models of polysyllabic word reading.