![]() This is surprising, as children's phonological sensitivity to supra-segmental features of speech develops early in all languages, well before the onset of formal literacy instruction. While an impairment in segmental processing in dyslexia has long been noted (e.g., Tallal and Piercy, 1974 Snowling, 1981), supra-segmental sensitivity has only recently been a focus of study, and then mainly in English (e.g., Wood and Terrell, 1998 Goswami et al., 2002, 2010). As simple decoding (word reading) requires the acquisition of phonology-orthography correspondences at different grain sizes (segmental for alphabetic languages, syllabic for some character-based scripts), this cognitive “phonological deficit” affects reading acquisition in dyslexia across languages. Phonological processing encompasses the encoding and representation of speech at a range of grain sizes, both segmental (i.e., phoneme) and supra-segmental (e.g., rime, syllable and stress). Introduction Speech Rhythm and Phonological Awareness in Dyslexiaĭyslexia is characterized across languages by difficulties in phonological processing (e.g., Snowling, 2000 Ziegler and Goswami, 2005). ![]() Dyslexics' perceptual difficulties in capturing the full spectro-temporal complexity of speech over multiple timescales could contribute to the development of impaired phonological representations for words, the cognitive hallmark of dyslexia across languages. This perceptual deficit in utilizing AM patterns in speech could be underpinned by less efficient neuronal phase alignment and cross-frequency neuronal oscillatory synchronization in dyslexia. These data suggest that dyslexia is associated with a reduced ability to utilize AMs <20 Hz for rhythm recognition. The data showed that dyslexics were significantly poorer at detecting rhythm compared to controls when they had to utilize multi-rate temporal information from pairs of AMs (Stress + Syllable or Syllable + Sub-beat). They were asked to use the acoustic rhythm of the stimulus to identity the original nursery rhyme sentence. 21 dyslexics and 21 controls listened to nursery rhyme sentences that had been tone-vocoded using either single AM rates from the speech envelope (Stress only, Syllable only, Sub-beat only) or pairs of AM rates (Stress + Syllable, Syllable + Sub-beat). We study 3 important temporal rates: “Stress” (~2 Hz), “Syllable” (~4 Hz) and “Sub-beat” (reduced syllables, ~14 Hz). Here, we assess the ability of adults with dyslexia to use speech AMs to identify rhythm patterns (RPs). ![]() Speech contains AM patterns at multiple temporal rates, and these different AM rates are associated with phonological units of different grain sizes, e.g., related to stress, syllables or phonemes. ![]() The “phonological deficit” in dyslexia may arise in part from impaired speech rhythm perception, thought to depend on neural oscillatory phase-locking to slow amplitude modulation (AM) patterns in the speech envelope. Department of Psychology, Centre for Neuroscience in Education, University of Cambridge, Cambridge, UKĭyslexia is associated with impaired neural representation of the sound structure of words (phonology). ![]()
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