METRICAL STRESS SENSITIVITY AND READING SKILLS IN ADULTS

Abstract

Speech rhythm emerges from the alternating pattern of stressed and unstressed syllables in spoken language. It contributes to language development by helping with segmentation of the continuous speech signal into discrete linguistic units. There is increasing evidence for a link between speech rhythm perception skills and early reading acquisition. In addition, poor readers and individuals with dyslexia show deficits on speech rhythm tasks. However, it is unclear whether these deficits reflect impaired representations of word stress resulting from auditory processing deficits (i.e., speech rhythm sensitivity), or alternatively, an impaired ability to compare and contrast speech rhythm cues (i.e., speech rhythm awareness). The main research question was to investigate to what extent individual differences in speech rhythm sensitivity and speech rhythm awareness correlate with reading skills. To this end, we developed a revised version of the DEEdee task used by Whalley and Hansen (2006). Participants read written words and listened to pairs of spoken “deedee” pseudowords. They were required to decide which “deedee” was pronounced with the same stress pattern as the written word. Accuracy rate on the task was used as a measure of speech rhythm awareness. Participants’ brain responses were recorded using electroencephalography (EEG) and event-related potentials (ERPs) elicited by the matching and mismatching “deedee” pseudowords. They were compared to measure speech rhythm sensitivity. Participants’ scores on the English and Reading sections of the ACT were used as literacy outcome measures. Results showed significant differences between the brain responses associated with the “deedee” pseudowords with matching and mismatching stress patterns. In addition, increased awareness to the least common stress pattern in English was found to be significantly correlated with reading skills. In contrast, stress rhythm sensitivity did not correlate with any of the reading measures. These findings favor the view that poor readers may not have impaired prosodic representations, but rather deficits in their ability to access and/or manipulate these representations.