Specific Reading and Writing Difficulties

Kieran Harrington, 12/3/2015

Overview

• What is “dyslexia”?

• Multiple manifestations

• Multiple Definitions

• Multiple Causes

• Two principal types of “dyslexia”: phonological and superficial

• Phonological and lexical components

• A neutral working understanding

What is Dyslexia?

Dyslexia is evident when accurate and fluent word reading and/or spelling develops incompletely or with great difficulty (British Psychological Society, 1999)

Researchers such as Professor Julian Elliot believe the term dyslexia should be abandoned as it is not scientific and is imprecise

Multiple Manifestations of “Dyslexia”

• Difficulty with rhymes • Difficulty with identifying syllables • Difficulty blending sounds • Word retrieval difficulty • Slow reading • Poor comprehension • Persistent spelling difficulty • Difficulty with the organization of texts and sequencing stories • Omission or addition of letters • Difficulty with summarizing stories • Difficulty in following multiple instructions • Difficulty taking notes and messages • Inability to read nonsense words • Letter reversal • Syllable reversal • Difficulty with rapid naming • Poor auditory memory

Deficit and Discrepancy Definitions

• World Federation of Neurology (1968) ‘A disorder in children who, despite conventional classroom experience, fail to attain the language skills of reading, writing and spelling, commensurate with their intellectual abilities.’

• Diagnostic and Statistical Manual of Mental Disorders (DSMV-IV, 1995) Reading performance is lower that that expected as far as age, education and IQ are concerned

Specific Definitions

• Hoien and Lundberg (1991) ‘Dyslexia is a disability in the use of the written language code, based on a deficit of the phonological system of oral language.’

• Orton Society for Dyslexia (1994) Dyslexia is a problem specific to language, with a constitutional basis, characterized by difficulties in decoding simple words and reflecting insufficient phonological processing

Causes of “Dyslexia”

• Phonological deficit hypothesis • Visual deficit hypothesis • Magnocellular deficit theory • The planum temporale link • Automitization deficit hypothesis • Cerebellar deficit hypothesis • The English spelling system • Integrated hypothesis

Phonological Deficit Hypothesis

Dyslexia is caused by problems in the phonological system of processing (the individual has difficulty in using the alphabet to decode reading and encode writing and this can be seen clearly with non-word testing)

The basic hypothesis posits a structural deficit in the left hemisphere of the brain.

(see also Ramus, 2003; Snowling, 2000; Stein & Walsh, 1997; Wolf et al., 2002)

• Shankweiler and Liberman (1972)

Visual Deficit Hypothesis

• Orton (1925) proposed that this was characterized by a tendency to see letters and words

inverted

• Pavlidis (1981) pointed to oculomotor system disorders

This theory maintains that it is a deficit/disorder specific to the visual system

New formulations of these theories signal that dyslexia is caused by a specific deficit in the transfer of sensory information from the eyes to the processing area in the cortex.

Magnocellular Deficit Theory

• Stein and Walsh (1997)

Magnocellular theory attempts to combine Cerebellar Deficit Hypothesis, the Phonological Deficit Hypothesis, Rapid Auditory Processing Theory, and Visual Theory to explain dyslexia. It proposes that the magnocellular dysfunction is not only restricted to the visual pathways but also affects auditory and the tactile pathways.

The magnocellular visual pathway tells us Where objects are in relation to where we are and influences How we react in relation to those objects.

The Planum Temporale Link

• Galaburda, Corsiglia and Rosen (1987) They found (post mortem) differences in the planum temporale and the thalamus and thus linked unusual morphology of the planum temporale to developmental dyslexia

The planum temporale is within Wernicke’s area, which is thought to be involved in auditory processing and phonological processing.

Automitization Deficit Hypothesis

• Bowers and Woolf (1993, 1999); Nicholas and Fawcett (2001)

These studies look at people who have difficulty in automating (making it automatic or attention-free) reading. Word recognition never becomes automatic and therefore the ability to predict and comprehend are affected.

Note: this difficulty with automaticity is found with other non-reading tasks as well.

Cerebellar Deficit Hypothesis

• Nicholson & Fawcett, 1994

This study and tests look at evidence emerging in the US which suggests that the cerebellum might be involved in language dexterity, via rich connections with the language area (Broca’s area) of the brain.

The Responsibility of the English Spelling System

• Phonemes (the sounds) > 44

• Graphemes (the letters and combinations need to represent these sounds ) > 230 +

The 44 phonemes (sounds)

Approximate comparative phoneme-grapheme correspondence

Language Phonemes Graphemes

English 44/45 230+

French 37 103+

Portuguese 37 93

Irish 44 94

German 42 71

Polish 37 46

Italian 25 30

Spanish (Castilian) 24 29

Finnish 30 30

Note: these numbers are not the result of scientific studies of the different languages, but of manual counts

Opaqueness-Transparency Continuum of Grapheme-Phoneme Association

Irregular Regular

Phoneme-grapheme correspondence Phoneme-Grapheme correspondence

Opaque Orthography Transparent Orthographies

Portuguese Spanish

French Italian

English Finnish

Integrated Hypotheses

E

N

V

I

R

O

M

E

N

T

A

L

General Cerebral Abnormality

Biological level

Poor learning Specific Deficit of writing system

Cognitive/linguistic level

Specific Alterations Poor alphabetic skills

Behavioural level

• Frith proposes that dyslexia be explained from various descriptive levels and disciplines (1997,1999)

Two Types of Dyslexia

• Stanovich (1988,1991) Phonological difficulties and other cognitive difficulties

• Wolf, et al (1994, 2000) Phonological difficulties and fast naming skill deficiency (and those who had problems in both

• Castles and Coltheart (1993) In research with acquired dyslexia they found two patterns, those with difficulty in reading nonwords or could read nonwords but had difficulty with irregular words.

• Manis et al. (1996,1999) They distinguish between phonological dyslexia and superficial (or lexical) dyslexia

Phonological “Dyslexia”

• Readers cannot use they grapheme-phoneme conversion route, i.e, they struggle associating the letters of the alphabet and their combinations with the 44 phonemes

• Readers can read familiar words well, but cannot read nonsense words or unfamiliar words

• Readers make morphological errors – they keep suffixes, for example, reading walked instead of walk

• Readers have more errors in function words (also known as non-lexical or non-content words) such as a lot/alot/

• Readers are not sensitive to word length

Superficial (lexical) “Dyslexia”

• Readers are unable to recognise a word as a whole

• Readers omit, add and substitute letters

• Readers confuse homophones (their/there)

• Readers try to regularize irregular words

Note: readers can sound out non-words through the grapheme-phoneme system

The component parts of phonological and lexical dyslexia

Phonological Components

• Phonemes (the sounds)

• Graphemes (the symbols/letters and combinations)

Phonemes

• Phonemes are the individual sound of a particular language; English has 44 (20 vowels and 24 consonants)

Short vowels: Ship Pen Book Man Cup Got Again

Long vowels: Sheep Boot Ball Car Girl

Diphthongs: Go Year Boy House Cane Hi Chair

Unvoiced Pat Tat Kit Fit Sit Shot Church Thin

Consonants: Voiced Big Dig God Void Zip Wing Ran Log Man Nod Ring Jam Yes Vision There

Graphemes

• Graphemes are the letters (visual symbols/the alphabet) used for particular languages and the combination of these letters:

English single letters: a,b,c,d,e,f,g,h,I,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z As there is no exclusive one-to-one correspondence between graphemes and phonemes in English, many different letters and combinations of letters are used to represent the 44 sounds (phonemes) of English. In the tables in the next two slides I have listed the common spelling in English used to represent the sounds. I have counted 73 different ways of spelling the 24 consonants and 80 ways of spelling the 20 vowels. The list is not exhaustive. These do not include, for example, the combinations that are used to spell words such as scream. The complexity demonstrated here gives some idea of the huge task facing children and adults learning to read English, especially those with specific reading difficulties.

Common consonant graphemes (written letter combinations for the 24 English phoneme consonants)

Phoneme Word Examples Common graphemes (spellings)

/p/ pit, spider, stop p

/b/ bit, brat, bubble b

/m/ mitt, comb, hymn m, mb, mn

/t/ tickle, mitt, sipped t, tt, ed

/d/ die, loved d, ed

/n/ nice, knight, gnat n, kn, gn

/k/ cup, kite, duck, chorus, folk, quiet k, c, ck, ch, lk, q

/g/ girl, Pittsburgh g, gh

/ŋ/ sing, bank ng, n

/f/ fluff, sphere, tough, calf f, ff, gh, ph, lf

/v/ van, dove v, ve

/s/ sit, pass, science, psychic s, ss, sc, ps

/z/ zoo, jazz, nose, as, xylophone z, zz, se, s, x

/θ/ thin, breath, ether th

/ð/ this, breathe, either th

/ʃ/ shoe, mission, sure, charade, precious, notion, mission, special sh, ss, s, ch, sc, ti, si, ci

/ʒ/ measure, azure s, z

/tʃ/ cheap, future, etch ch, tch

/ʤ/ judge, wage j, dge, ge

/l/ lamb, call, single l, ll, le

/r/ reach, wrap, her, fur, stir r, wr, er/ur/ir

/y/ you, use, feud, onion y, (u, eu), i

/w/ witch, queen w, (q)u

/h/ house, whole h, wh (Total = 73)

Common vowel graphemes (letter combinations for the 20 English vowel sounds)

Phoneme Word Examples Common Graphemes (Spellings)

/i:/ see, these, me, eat, key, happy, chief, either ee, e_e, -e, ea, ey, -y, ie, ei

/ɪ/ sit, gym i, y

/ei/ make, rain, play, great, baby, eight, vein, they a_e, ai, ay, ea, -y, eigh, ei, ey

/e/ bed, breath e, ea

/æ/ cat a

/ai/ time, pie, cry, right, rifle i_e, ie, -y, igh, -i

/ɒ/ fox, swap, palm o, wa, al

/ʌ/ cup, cover, flood, tough u, o, oo, ou

/ɔ:/ saw, pause, call, water, bought, door aw, au, all, wa, ough, oo

/əʊ/ No, go, vote, boat, toe, snow, open o_e, oa, oe, ow, o-

/ʊ/ took, put, could oo, u, ou

/u:/ moo, tube, blue, chew, suit, soup oo, u_e, ue, ew, ui, ou

/ɪə/ beer, here, tier eer, ere,ie

/ɔɪ/ Boy, coil oi, oy

/aʊ/ out, cow ou, ow

/ɜ:/ her, fur, sir, learn, world, er, ur, ir, ea, or

/ɑ:/ cart ar, a

/ʊə/ sure, tour ur, our

/eə/ chair, there, air, ere

/ə/ again, mother, pistol, a, er, ol, (80 in total here)

Lexical Components

• Regular words

• Irregular words

• Non-words (also known as nonsense words or pseudo-words)

• Homophones

Regular words

• A regular word is a word in which all the letters represent their most common sounds. Regular words are words that can be decoded phonologically.

Sounding out

Saying the whole word Sight word reading Automatic word reading

Progression of regular word reading

Examples: Tim, timber, timberyard, Shibboleth, peripatetic,

Irregular words

• Some irregular words in the English language do not conform to “normal” spelling and are thus difficult to decode and encode

• It may also be that the reader has not yet learned the letter-sound correspondences in the word

Examples

Gym, gymnast, gymnastics

Aisle, subtle, deny,

Pseudo-words

• A pseudo-word or non-word is a unit of speech or text that appears to be an actual word in a certain language (it conforms to normal orthographical and phonological rules), but it has no meaning

Examples:

Fer, hin, trolb

tegwop,

stansertish

Note: the ability to sound out these words in an indication that there is no difficulty with the grapho-phonic system.

Homophones

• A homophone is a word that is pronounced the same as another word but differs in meaning, and may differ in spelling

Working Understanding of ‘Dyslexia’

• Specific reading and writing problems reflect the struggle of a significant proportion of the population when attempting to associate graphemes (the 26 letters of the English alphabet and their multiple combinations) with phonemes (the 44 singular sounds - vowels and consonants - of English).

• Educationally, the focus should be put on helping these people to read rather than wasting time debating the validity of the term.