Syllabic units in children's word recognition.

When elementary-aged children read unknown polysyllabic words, they must parse the orthographic input in order to decode it. Prior studies have not shown clearly whether syllables-as opposed to letters or morphemes-are perceptual units, particularly in children. Children in second, third, and fourth grade (N = 123) with and without reading difficulty (RD) were asked to read polysyllabic pseudowords (N = 98), and their accuracy, response time (onset latency), and response length (fluency) were recorded. In explanatory item-response analyses, the number of syllables in a word was negatively associated with pronunciation accuracy, latency, and fluency, even when accounting for the number of letters and morphemes. A syllable-by-grade interaction for onset latency showed that the syllable effect was smaller in higher grades, suggesting ongoing development of automaticity with syllabic features. A syllable-by-RD interaction for onset latency and fluency showed a smaller syllable effect for students with RD, suggesting that polysyllabic word processing is challenging for these students at all syllable lengths. The presence of negative syllable effects when accounting for the number of letters and presence of morphemes suggests that syllables are unique sublexical units that require reader attention when pronouncing unfamiliar written words. The mechanisms posited to explain these large negative effects include the need to parse printed words into orthographic syllables, inconsistency in the pronunciation of vowels in polysyllabic words, and the need to assign lexical stress. Overall, the results provide strong evidence that words' syllabic features require processing that makes words with more syllables harder for elementary-age readers, regardless of the number of letters in the words, and that the degree to which syllabic features impact student performance depends on their age and reading ability.