title: Amplitude envelope onsets and developmental dyslexia: A new hypothesis.
abstract: A core difficulty in developmental dyslexia is the accurate specification and neural representation of speech. We argue that a likely perceptual cause of this difficulty is a deficit in the perceptual experience of rhythmic timing. Speech rhythm is one of the earliest cues used by infants to discriminate syllables and is determined principally by the acoustic structure of amplitude modulation at relatively low rates in the signal. We show significant differences between dyslexic and normally reading children, and between young early readers and normal developers, in amplitude envelope onset detection. We further show that individual differences in sensitivity to the shape of amplitude modulation account for 25% of the variance in reading and spelling acquisition even after controlling for individual differences in age, nonverbal IQ, and vocabulary. A possible causal explanation dependent on perceptual-center detection and the onset-rime representation of syllables is discussed.
authors.affiliation: Institute of Child Health, University College London, London WC1N 1EH, United Kingdom. u.goswami@ich.ucl.ac.uk
authors.forename: Usha
authors.initials: U
authors.lastname: Goswami
authors.forename: Jennifer
authors.initials: J
authors.lastname: Thomson
authors.forename: Ulla
authors.initials: U
authors.lastname: Richardson
authors.forename: Rhona
authors.initials: R
authors.lastname: Stainthorp
authors.forename: Diana
authors.initials: D
authors.lastname: Hughes
authors.forename: Stuart
authors.initials: S
authors.lastname: Rosen
authors.forename: Sophie K
authors.initials: SK
authors.lastname: Scott
mesh_terms: D001184:Articulation Disorders / Q000150:complications*; D001308:Auditory Perceptual Disorders / Q000150:complications*; D002648:Child; D004410:Dyslexia / Q000209:etiology*; D006801:Humans; D008137:Longitudinal Studies