Phonology of Dyslexia: Phonological and neurobiological explanations of cross-linguistic variations
Abstract : The neurobiological disability called dyslexia (< Greek dys- ‘impaired’ + lexis ‘word’) is a specific learning disability (LD) that affects literacy skills: both decoding (pronouncing written words) and encoding (spelling words). It has been generally assumed that congenital form of dyslexia, termed developmental dyslexia, stems from a particular problem in language acquisition affecting phonological awareness. However, the exact nature of phonological awareness has not yet been made clear. The majority of studies on dyslexia have been carried out with respect to Roman alphabetic languages, most especially English, and it might be the case that certain truths of dyslexia remain unrevealed under such research situations.
This talk first establishes the relevance of the mora-basic hypothesis that moras (CVs) are the units underlying all human natural languages. It then spotlights a seemingly mysterious discrepancy in the prevalence of phonological dyslexic populations between the English-speaking world and the Japanese-speaking world: namely as high as 17% for the former and as low as 1% for the latter. On the basis of English dyslexic reading marked by an overproduction of moraic (CV) units in the absence of rhyme (VC) units, the talk will show that the discrepancy is due to differences in prosodic structures between the two languages. For rhyme(VC)-oriented English, readers must depict the unit rhyme through prosodic restructuring from the underlying CV-C (do-g) to rhyme-oriented C-VC (d-og). A failure to do so manifests as phonological dyslexia. For mora(CV)-oriented, rhymeless Japanese, such prosodic restructuring is irrelevant, and phonological dyslexia is largely undetected.
The talk furthermore moves on to exploring possible explanations of a failure in such a prosodic restructuring. From the articulatory phonological point of view, onset consonants are coarticulation of the following vowels. Moras (CVs) are thus formed automatically and essentially free. In contrast, coda consonants are not coarticulation with the preceding vowels. Forming rhymes (VCs) instead requires a temporal-spatial decision load, which a dyslexic mind is unable to bear. Mora inclination is explained accordingly.
The talk will deepen the above view and come to claim that mora-forming coarticulation is easy because it is a synchronized articulatory behavior, akin to a synchronized human locomotive behavior. This view conforms to a human neurobiological restriction inclined toward synchronized behavior, which is claimed to be acquired in the process of human evolution.
Bio: Prof. Katada's main contribution to formal linguistics includes a notion of operator anaphor, coined by her and extended to a general notion of operator variable in the nominal system of syntax, whereby anaphoric relations are formalized at the level of logical form of language. Her work on the prosodic unit of mora, which has been widely cited since its publication in 1990, has evolved into arguing for the presence of floating mora, a notion that would unify representations of long-vowels and long-consonants (geminates).
For the last decade, she has been looking into areas of research other than linguistics proper, including areas of neurodevelopmental deficits associated in particular with Williams syndrome, dyslexia, and other developmental disorders subsumed under the notion of ASD (Autism Spectrum Disorders). Her contention is that 'disability' is a continuum notion that embraces everyone. This contention leads to a natural link to notions of IE (inclusive education) and EFA (education for all), of which she has been an advocate. She exploits various atypicalities revealed by affected subjects and explores them as serving a unique window to how the human mind is organized for language and cognition.
As a faculty member in Science and Engineering, she explores basic mathematics in English as a fundamental tool for thinking and scientific research and as most accessible ESP (English for specific purposes) for science and engineering students with certain dispositional tendencies, namely those associated with communication vulnerabilities.
Her secondary but important interest concerns human rights in the autonomy of academia of the modern age of Japan. Her community contributions expanding overseas are the natural consequences of her diverse interests in human beings.Date: 2017-Sep-15 Time: 14:00:00 Room: 336