Eye Movements During Silent Reading of Poetry Reflect Hierarchical Metric Structure

The current study investigates the influence of hierarchical metric structure on silent reading behavior during naturalistic reading, thus extending the scope of implicit prosody research beyond violation paradigms. By applying Fabb and Halle's prosodic framework to Dr. Seuss's The Cat in the Hat, we examined how a five-level metric hierarchy affects eye-tracking measures, independent of known factors such as word frequency, length, text emphasis, and syntactic structure. Thirty-two native English-speaking adults silently read the text presented without images, while their eye movements were recorded. Metric hierarchy explained overall variance above and beyond other linguistic factors in both early and late reading measures, consistent with patterns observed during oral reading of the same text. Moreover, the metric effect interacted with linguistic factors at lower levels of the hierarchy: closed-class words aligned with lower levels were read faster than open-class words. Exploratory analyses disentangling layout and end-of-page effects showed that while the addition of metric structure explains overall variance in all reading measures above and beyond other linguistic factors, only early reading measures are affected by lower levels of the metric hierarchy when analyzing the first stanza of two-stanza trials. These results demonstrate that the influence of metric structure during silent reading of naturalistic poetic text is qualitatively similar to its influence on spoken durations, providing further support for the role of implicit prosody in on-line sentence processing. These findings pave the way for further research into the role of prosody in reading comprehension, particularly in less metrically-regular texts and across developmental stages.