Writing Isabelle Rapin Seminar on developmental disabilities December 14, 2012 No conflict of interest Quick Review: Dysphasia and Dyslexia 2 Oral & Written Language Oral language • develops gradually without specific instruction • provided adequate exposure to its conversational use Reading written language • grafted on oral language • requires specific instruction Producing written language • grafted on reading • + requires fine motor skill 3 One-way path in language processing Input (sensory) Decoding Output (motor) Higher order processing Encoding 4 Levels of language encoding 1. Phonology (articulation/intelligibility, prosody) 2. Grammar/syntax 3. Semantics: word/sentence 4. Pragmatics: verbal/nonverbal 5 Language areas in the left hemisphere 6 Required mechanisms for reading Auditory processing Phonological awareness Phonological decoding (regular non-words) Orthographic coding (irregularly spelled words, homonyms) Single word reading (accuracy, speed) Spelling ability (real words, non-words, irregular words) segmentation) (phoneme/letter relation, word Spika et al., Behav. Genet., 2011 7 Phonological level Phoneme = smallest linguistic sound unit in any particular language Syllable = co-articulated phonemes processed as units (chunks) Lexicons (i.e., dictionaries) in our brains • Phonologic Auditory Visual (letters, ideograms [complex=syllabic]) • Word meanings (semantics) • Word relations (grammar) 8 Phonologic/reading development > birth: can make all potential speech-sound discriminations > ~ 1 year: chunk words into whole expressions > ~ 2 years: begin to segment single words 3-5 years: progressive awareness of phonemes, e.g., rhymes, initial consonant sounds, syllables, phonetic sequences, cadences kindergarten: starting awareness of letter-sound mapping 1st grade: read/spell mostly regular words 2-3 grades: ↑ fluency, learn irregular words, ↑ vocabulary, begin to read for meaning > ~ 3rd grade: fluent reading by-passes phonologic decoding, goes directly to lexicon (word dictionary) 9 Progressive reading competence Word recognition (phonology) • Phonetically consistent (words/nonwords) • Phonetically inconsistent (e.g., yacht, blood) Reading fluency (direct access to lexicon) Comprehension • At the word level (vocabulary) • At the sentence level (+ grammar) • At the idea level (reading now automatic) 10 Cortical activation during reading Shaywitz et al. 2008 11 Brain basis of most prevalent dyslexia Underactivity of posterior brain regions Overactivity of interior frontal cortex concerned with speech articulation Remediation improves but does not “cure” dyslexia • Tend to read slowly • Fluency improves but difficulty reading non-words persists • Poor spelling, etc. very likely 12 WRITING 13 Writing deficits Writing: hierarchically related to reading Dysorthographia (poor spelling): the telling sign of compensated dyslexia Spelling and writing: related to speech articulation • all 3 outputs involve translating inner language into sound-based fine motor commands • Speech requires continuous feedback monitoring of the accuracy of production (phonological loop) 14 Modes of language output 1. gestures 2. speech articulation 3. writing handwriting spelling 4. Sign, other symbolic codes 15 What is writing? “Transcription is a basic cognitive process … that enables the writer to translate internal language into external written symbols to express ideas in written language. … Transcription ability draws on handwriting and spelling.” Berninger et al . 2009 16 Language outputs All are motor Skilled speakers, readers, & writers program motor commands to express retrieved chunks of inner language from the lexicon Execute commands ‘on line’ in parallel with • retrieval of next language chunk to be expressed • and programming of the commands for its production Requires a high degree of over-learning and automation 17 Relation of reading & writing to speech articulation Children learning to read regularly articulate sotto voce what they are deciphering They do as well when writing Fades as reading/writing become automatized Many compensated dyslexics continue silent articulation when reading and writing 18 VAA: Writing vs. copying 19 Development of speech awareness 1. At birth: ability to make any auditory discrimination adopted by any language 2. Discriminate the stream of speech from other environmental sounds 2. Segment word-chunks from the stream 3. Segment syllables in phrases & words 4. Segment individual phonemes 20 Auditory Processing for Reading Identifying/segmenting individual words Steps toward identifying individual phonemes/syllables, e.g., • First phonemes/syllables • Phonemic games • Rhymes Reciting the alphabet Learning letter names Relating letter names to phonemes 21 Prerequisites for reading/writing Syllabication, then individual phonemes Relate letter names/shapes to perceived and produced speech Learn to point to, tap on keyboard, reproduce (write) letters on the basis of letter names 22 Writing Orthography (letter/syllable spelling) • essential basis for learning to read and write Whole word knowledge • essential for fluent reading/writing Speaking/writing • translation of inner language into motor commands for speech articulation writing letters. keyboarding 23 Writing Engages Multilevel Processes integration of vision + audition phonologic discrimination several memory processes attention acquisition of specific fine motor skills 24 Memory requirements Short term sequential memory for spoken/read phonemes, words, phrases Working memory: needed to • • • • • retrieve needed material from long term storage compare new input with stored material evaluate on-line significance of input prepare commands for motor output Monitor output Store output 25 Visual perception Letter shapes • Rounded • Angular Right/left orientation Up/down awareness Sizing Spacing 26 Auditory/visual integration In response to letter names: • • • • identifying corresponding printed caps identifying printed lower case letters identifying cursive letters eventually identifying unusual scripts/fonts 27 Letter reversals Examples: p/q, b/d, d/p, b/q, m/w, backward f, s, z, etc. Most in lower case print Normal in preschoolers and up to ~ 3rd grade Not predictive of either dyslexia or dysgraphia Not due to defective visual perception If persistent consider • inefficient working memory • Spatial, R/L confusion (incl. Gerstmann syndrome) 28 Dysgraphia Classic motor deficit Deficit in rapid fine motor control (timed) Deficient procedural memory inadequate learning of motor sequences Inattention (ADHD) Lack of motivation 29 Macrographia • Frequent in ASD (e.g., DeLong, Mostofsky) • Also frequent in ADHD (also inconsistent size and legibility) Micrographia • Frequent in OCD • Sometimes in Asperger-type ASD 30