Presentation on theme: "1 When does phonological impairment cause literacy problems? Dorothy Bishop Experimental Psychology University of Oxford Powerpoint and references will."— Presentation transcript:
1 When does phonological impairment cause literacy problems? Dorothy Bishop Experimental Psychology University of Oxford Powerpoint and references will be on my website
2 What we have learned today Phonology is not a single skill Phonology is not a single skill Segmental vs. higher-level structure Segmental vs. higher-level structure Input vs. output Input vs. output Perception vs. memory Perception vs. memory Hard to disentangle, but people are devising wonderfully ingenious tasks Hard to disentangle, but people are devising wonderfully ingenious tasks
3 Why is phonology important in reading? Two ways to learn to read a word Two ways to learn to read a word A. If word is totally unfamiliar: decode letters into sounds to achieve pronunciation /k/+/a/+/m/+/ /+/l/ CAMEL /kam l/ /'kaml/
4 Phonological skills involved in decoding Knowledge of mappings from letters to sounds Knowledge of mappings from letters to sounds Distinct representations of phonemes Distinct representations of phonemes Ability to segment syllables into phonemes Ability to segment syllables into phonemes Combine sequence of sounds into syllables Combine sequence of sounds into syllables Match assembled string to a similar lexical entry Match assembled string to a similar lexical entry Learn to do this rapidly with larger orthographic units Learn to do this rapidly with larger orthographic units
5 Why is phonology important in reading? Another way to learn to read a word Another way to learn to read a word B. Incorporate orthographic information in lexical representation of a known word /kaml/ lexical representation
6 Why is phonology important in reading? Another way to learn to read a word Another way to learn to read a word B. Incorporate orthographic information in lexical representation of a known word /'kaml/ CAMEL lexical representation Does not require phonological analysis
7 Reading without decoding Patient PS, L hem. infarct aged late 40s – Phonemic errors on reading aloud and spontaneous speech – Excellent comprehension of written words; can judge synonyms, define words, match to pictures – Homophones: can only relate to correct meaning, i.e. cannot respond “inherits” to word “air” – Nonwords: very poor at reading Hanley, J. R., & Mcdonnell, V. (1997). Are reading and spelling phonologically mediated? Evidence from a patient with a speech production impairment. Cognitive Neuropsychology, 14, 3-33.
9 What has not been discussed Phonological skill Literacy
10 Phonological deficits in dyslexia: a symptom rather than a cause? Evidence from: 1. Orthographic influences on phonological tasks 2. Phonological processing in non-literate people 3. Phonological skills as predictors of literacy 4. Literacy in children with sensory or motor conditions affecting phonology
11 1. Orthographic influences on phonological tasks
12 Orthographic influences on phonological judgement Judging whether pictures have rhyming names; Children more accurate if can use orthography Bishop et al, 1989
13 Orthographic influences on phonological judgement Phoneme awareness: task performance affected by orthography Castles et al, 2003 Tasks where orthography no help (or may hinder) e.g., take the 'w' from squabble cf. transparent condition e.g., take the 'r' from struggle Also phoneme reversal: gnat vs mood.
14 2. Phonological processing in non-literate people
15 Phonological processing in non-literate people “Illiterates, who lack the linguistic construct ‘phoneme’, cannot perform oral tasks that require the awareness of that construct” Tarone & Bigelow, 2005, p 82 Seminal study by Morais et al (1979): Non- literate Portuguese worse than Belgian first- graders at tasks of phoneme deletion/addition; those with some literacy attainments did better
16 Comparison of literate vs. nonliterate adults: summary Do not differ on – Rhyme judgement – Phoneme discrimination – Word repetition – Nonword repetition (short) – Categorical perception* Do differ on – Phoneme deletion – Phonological fluency – Nonword repetition (long) * but less precise categorical boundary; Serniclaes et al, 2005 See also Kosmidis et al, 2004; Castro-Caldas et al, 1998; de Santos Loureiro et al, 2004
17 3. Early phonology measures as predictors of later reading
18 Early phonology measures as predictors of later reading – Bradley and Bryant (1985); famous demonstration that preschool phonological awareness accounted for significant variation in reading outcome after allowing for IQ, vocabulary. BUT! – “...the sound categorization tests that we gave to the 4-year- old children were really rather good at picking up those children who would eventually become good readers. The percentage success.. ranged from 40 to 53%. On the other hand, these same tests were very weak indeed at predicting reading failure. The successful rate of prediction of poor readers ranged from as low as 14% to 28%.” – Bradley & Bryant, p. 105
19 Wimmer et al, 1991 At start of grade 1 (children non-readers), good PA predicted good reading 7 mo later, but many with poor PA also did well. Children differ in the ease with which they pick up PA when introduced to literacy. Positive correlation between preschool phonology and later reading could be consequence of some preschoolers reading (see also Castles and Coltheart, 2004)
20 Bishop et al (in press) comparison of pure LI and LI + reading disability (RD) – Retrospective analysis of measures taken at 4 years. Did not differ on: Nonverbal ability Vocabulary Oral comprehension Sentence memory Phonological awareness Nonword repetition NB significantly impaired at 4 yr on all these when compared to control group
LI do not differ from LI+RD at any time time 1 = 4 yr time 2 = 6 yr
Significant interaction: time x group LI do not differ from LI+RD at time 1, but do differ at times 2 and 3 4 yr: CNRep 20 items 6 yr: CNRep 40 items 9 yr: NEPSY time 1 = 4 yr time 2 = 6 yr time 3 = 9 yr
LI worse than LI+RD at time 1, but do worse still at time 3 time 1 = 4 yr time 3 = 9 yr 4 yr: Goldman Fristoe articulation 9 yr: NEPSY oromotor
24 Differences in phonological processing emerge over time Nonword repetition and oromotor (articulation): groups diverge with age
25 4. Children with sensory or motor problems affecting phonology
26 Children with impaired speech production In general, these do not seem to impair decoding unless accompanied by broader language difficulties: Structural problems – e.g., cleft palate (Stackhouse, 1982) Structural problems – e.g., cleft palate (Stackhouse, 1982) Neurological problems, e.g. cerebral palsy (Bishop & Robson, 1989) Neurological problems, e.g. cerebral palsy (Bishop & Robson, 1989) Problems of unknown (?genetic) origin, - speech sound disorder (see review by Pennington & Bishop, in press) Problems of unknown (?genetic) origin, - speech sound disorder (see review by Pennington & Bishop, in press)
27 Children with impaired phoneme discrimination Study comparing children with mild- moderate hearing loss and those with SLI Study comparing children with mild- moderate hearing loss and those with SLI Briscoe et al, 2001 Hearing impaired had sensorineural hearing loss from 25 to 65 dB across speech frequencies Hearing impaired had sensorineural hearing loss from 25 to 65 dB across speech frequencies
28 Phonological discrimination Bridgeman & Snowling test Same/Different judgements re real and nonwords with final s, t, st, or ts ‘Different’ differ either in single segment (e.g. ‘tot’ vs. ‘toss’) or in sequence (e.g. ‘gets’ vs. ‘guest’)
29 Phonological discrimination * * significant difference from group CA
Phonological awareness task (Introducing monster): This is ‘Wug’. He likes things that sound like his name. Which do you think he will choose? The cake, the jug, the leaf or the boat?
31 Phonological awareness * * * significant difference from group CA
34 Conclusion re hearing loss Mild-moderate hearing loss affects phonological discrimination and awareness, and nonword repetition (Briscoe et al) Yet children with mild-moderate hearing loss do much better than those with SLI on literacy see also Halliday & Bishop, 2005 Wake et al., 2006
35 Questions for discussion Is phonological deficit a causal deficit in SLI or dyslexia? Is profile of phonological deficits in SLI/dyslexia the same as that in illiterates? What are implications for intervention? Do we really understand how a phonological deficit could cause literacy problems? How important is nonsegmental level for understanding SLI? Why so little funding for research on these disorders compared with autism?