Language and CognitionColombo, June 2011

Day 3Child Language and Disorders

continued

Plan

• Specific language impairment• Phonological development• Phonological disorders

SLI - Definition

A developmental language disorder characterized by Gleason (2001, p. 504) as involving ‘delayed or deviant language development in a child who exhibits no cognitive, neurological or social impairment’. Children with SLI show impaired language development from birth (with problems which may either disappear during childhood or persist into adulthood) but are normal in other aspects of their physical, mental and social development (Radford 2006).

Specific language impairment

• It is estimated that 1 – 3% of preschool children have SLI

• Studies suggest that these children do not “catch up” with their same age peers and are at risk for reading problems and educational failure

Features of SLI

• From Bishop, 2007

Possible accounts

• Impairment in language processing vs. impairment in processing?

• Impairment in the language mechanism vs. impairment in language processing aptitude?– Competence or performance?

Procedural Deficit Hypothesis (PDH)

Ullman, M.T. & Pierpont, E.I. 2005. Specific Language Impairment is not Specific to Language: The Procedural Deficit Hypothesis. Cortex 41, 399-433.

"SLI can be largely explained by the abnormal development of brain structures that constitute the procedural memory system.”

• Procedural memory: “mental grammar”, syntax, some morphology

• Declarative memory: “mental lexicon”, vocabulary, idioms, irregular past-tense forms

Procedural memory

• Declarative vs procedural memory• Procedural:

– Learning new and controlling established motor and cognitive skills, habits, and other procedures

• E.g. typing, riding a bike, skilled game playing

– Aspects of rule-learning– Learning and performing skills involving sequences

• Includes system involved in learning, representation, and use of procedural memory

Brain structures involved in procedural memory

• a network of interconnected structures rooted in frontal/basal-ganglia circuits, subserves the learning and execution of motor and cognitive skills.

• recent evidence implicates that this system is important for specific aspects of grammar

• a significant proportion of individuals with SLI suffer from abnormalities of this brain network, leading to impairments of the linguistic and non-linguistic functions that depend on it

• grammatical and lexical retrieval deficits are strongly linked to dysfunctions of the basal ganglia (BG), and of the frontal cortex, esp. Broca’s area

Auditory (temporal processing) deficit hypothesis

Merzenich, M. Jenkins, W., Johnston, P., S., Schreiner, C., Miller, S. L. & Tallal, P., (1996) Temporal Processing Deficits of Language-Learning Impaired Children Ameliorated by Training, Science, v. 271, p. 77-81. (=Fast ForWord)

• Task: discriminate between speech stimuli -six syllable contrasts ([ba] versus [da], [da] versus [ta], [ε] versus [ae], [dab] versus [daeb], [sa] versus [sta] and [sa] versus [sha]).

• Findings: – LI group made most errors discriminating syllables which were differentiated

by consonants and fewest errors on those differentiated by vowels. – The LI group was significantly poorer than the normal in discriminating all

syllables that incorporated brief temporal cues followed rapidly in succession by other acoustic cues.

– They also were impaired in discriminating [sa] versus [sha]. – They were unimpaired discriminating stimuli differentiated by vowels.

Perceptual Deficit Model

Leonard, L. B.1989. Language learnability and specific language impairment in children. Applied Psycholinguistics 10: 179-202

• Following the sonority scale (Srlkirk 1984), Leonard proposes that SLI is an Auditory Perceptual Deficit: – Vowels and diphthongs are easier to perceive than consonants (and

consonants are particularly difficult to perceive when occurring in clusters of two or more successive consonants)

– Stressed vowels are easier to perceive than unstressed vowels, long vowels and diphthongs are easier than short vowels, and full vowels are easier than reduced vowels

Percentage correct probes and spontaneous speech (Rice & Wexler 1995)

SLI N3 N5 -ed probe 27 45 92 -ed spontaneous 23 46 90 -s probe 22 44 91 -s spontaneous 37 60 89 BE probe 50 64 95 BE spontaneous 46 71 96 DO probe 30 47 90 plural 88 96 97 Prepositions 96 97 98

Feature Deficit Model

Gopnik, M. 1990. Feature blindness: A case study. Language Acquisition 1: 139-164

• Due to a genetic deficit SLI children do not have grammatical (syntactic-semantic) features in their grammar.

• A “global deficit”• But might be a graded phenomenon

SLI in Hebrew monolinguals Dromi et al. (1993, 1999)

• Predictions: With verbal morphology so central in Hebrew, a Semitic language, it was predicted that– a very few inflections, if any, would pose a problem for

children with SLI– inflections which carry more features would be more difficult

than those which carry fewer features with errors that show a simpler feature complex

• Method: Hebrew speaking children with SLI, ages 4-6, using a sentence completion task and enactments

Findings

• Sentence completion: while monolingual children with TLD scored at ceiling, children with SLI showed 80% success when one feature was involved, but hardly ever produce the target morpheme which represented two features (fem. pl.)

• Enactment: while monolingual children with TLD scored at ceiling, children with SLI showed 80% success when one feature was involved, but only 60% success when two features (person and gender) were involved

• While in English most errors are omissions, in Hebrew most errors are substitutions in which a morpheme which marks just one feature was used to replace a morpheme which marks two features

Verb inflection in Hebrew (Dromi 1999 et al) - present tense agreement items

0%

20%

40%

60%

80%

100%

Fem sing Masc plur Fem plur

SLI TLD - MLU

Rule Deficit Model Gopnik M & Crago MB. 1991. Familial aggregation of a developmental disorder. Cognition 39: 1-50

• Studying three generations of a family in London, Gopnik & Cargo concluded that they have the same syntactic abilities as MLU matched controls, but could not generate morphological rules (due to genetic failure of the dual mechanism of morphological acquisition).

Bishop (1994) - A study of 12 SLI children ranging in age from 8;2 to 12;11

• Took it off (in reply to ‘What did they do with the top part of the pram?’)

• It take me a long time (in reply to ‘Did it take you a long time to get better?)

• And then Mummy taked to the garage to xxx • He falled in (in reply to ‘What did Andrew do when

the ice gave way?’)• He sawed mine brother (in reply to ‘Has the doctor

ever been to see you?’)• The car has broked down • So is it just rules?

Agreement Deficit Model Clahsen H, Bartke S and Göllner S. 1997. Formal features in impaired grammars: a comparison of English and German SLI children. Journal of Neurolinguistics 10: 151-171

• Findings: – Past tense - 76% of main verbs and 89% of auxiliaries – 3Sg present tense - 49% of main verbs and 35% of

auxiliaries • SLI children have problems with acquiring

uninterpretable features, which make no contribution to the meaning of the sentence (semantically redundant), e.g., agreement features

Contexts for 3rd person auxiliaries in the corpus of Clahsen, Bartke and Göllner (from Radford 2006) - how do these

examples support their claim?

Contexts where adults would use a third person singular present form of the progressive auxiliary be

22. And boy picking ’em up (JW 11;03) 23. He jumping over a gate (WL 11;05). 24. Apples fallen out on the boy who pinching them (JW 11;03)25. The man taking the cat down on the ground (AZ11 12;03)26. The dog taking slipper off him (AZ11 12;03)27. Her hugging it (CT 13;11)

Contexts where adults would use a third person singular present form of the perfect auxiliary have

35. She sometimes buy stuff and then paint it what haven’t got coat of paint on it (RJ 11;11)

36. He been tied on (AZ12 13;0)

Contexts where adults would use a third person singular present form of the tense auxiliary do

37. He don’t know (JW 10;3) 38. He don’t get hungry (JW 10;03) 39. What, when he don’t go to work? (JW 10;03) 40. And the bus don’t take no notice (AZ11 10;3)41. And he don’t know how to (RJ 10;11)42. He don’t know how to put his brakes on (AZ12 11;0)

Mabel L. Rice, Kenneth Wexler, & Jennifer Francois (2001)

Passive Comprehension: Identification of Agent

0

0.15

0.3

0.45

0.6

0.75

0.9

SLI Lexically Matched Age Matched

Perc

ent C

orre

ct

At 5 years of age, children in the SLI group were below age peers in their comprehension of reversible full verbal passives, and similar to their younger lexically-equivalent peers

Van der Lely HKJ and Battell J (2003)

(a) Who Miss Scarlett saw somebody? (Response to ‘Miss Scarlet saw someone in the lounge. Ask me who’ – the target response being Who did Miss Scarlet see in the lounge?)

(b) Which Reverend Green open a door? (Response to ‘Reverend Green opened a door. Ask me which one’ – the target response being Which door did Rev. Green open?).

(c) What did Colonel Mustard had something in his pocket? (Response to ‘Something was in Colonel Mustard’s pocket. Ask me what’ – the target response being What was in Colonel Mustard’s pocket?).

Representational Deficit For Dependent Relations (RDDR)

Van der Lely, H.K.J. & Battell, J. (2003). Wh-movement in children with grammatical SLI: A test of the RDDR hypothesis, Language, 79, 153-18.1

• "SLI children have problems in handling non-local dependencies (between pairs of constituents which are not immediately adjacent) such as those involved in tense marking (which involves a T-V dependency both in the agreement-based analysis of Adger 2003 and in the Affix Hopping analysis of Radford 2004), agreement (which involves a subject-verb dependency), determining pronominal reference (which involves a pronoun-antecedent dependency), and movement (which involves a dependency between two constituents, one of which attracts the other)."

Deficit in Computational Grammatical Complexity (CGC)

Marinis, T. & van der Lely, H. K. J. (2007). On-line processing of wh-questions in children with G-SLI and typically developing children. International Journal of Language & Communication Disorders 42(5), 557-582.

“The CGC Hypothesis claims that the core deficit in some but not all forms of SLI is in the representation and/or mechanisms underlying the construction of hierarchical grammatical structures. For G-SLI children their grammar is characterized by Grammatical Structural Economy in syntax, morphology and for most phonology too. Thus, the least complex structure will surface. Within the syntactic component, the core deficit is in computing syntactic dependencies between constituents … Further, complexity is defined as the number of movement operations, thus subject questions are predicted to be less problematic than object questions because the former has one less movement operation”

Domain general, or domain specific?

• Deficits were also found for:– Lexical access– NWR– Narratives– Executive functions

• But pragmatics:– In children with SLI (14 Subjects: 3;11-4;10),

pragmatic principles develop normally as a function of age, rather than as a function of grammar developmental stage (Scheaffer et al, 2003)

Phonological development and disorders

Phonological development

• How children establish the sound sequences of their language

• Mental representations• Related to (but distinct from) phonetic

representations• Effects that sounds have on one another in

context• Structural system

Hierarchical view of language structures

• features phonemes morphemes words phrases discourse

• In principle, things can go wrong at any level• In practice, it’s hard to tell where a particular deficit

might be functionally located – e.g. an articulation deficit might result from a problem at the phonetic level, or at the phonological level – or it might just be an articulation problem

• Assessment is supposed to help us decide which level (if any one) is primarily affected

• Treatment can be directed at any of these levels

Phonological development• Normal processes applied to speech sounds• To some extent, these reflect the limitations of

the phonetic inventory at different developmental stages

• In normal phonological development, phonological processes are gradually eliminated as the child’s phonological system assimilates to the adult’s

Phonological processes in normal development

• See handout

Phonological theories

• Evaluating theories: levels of adequacy (Chomsky (1965)– Observational adequacy– Descriptive adequacy– Explanatory adequacy

• Theories of language: universality, restrictiveness, learnability

A note about learnability

• Children have to acquire both knowledge about ‘motor’ aspects of speech production, and knowledge about ‘linguistic’ aspects of speech production

• If these are distinct systems, then their development is essentially independent

• This means that one child could be having problems with the motor aspects of one sound AND the language aspects of another sound at the same time

• Therapy cannot be an all or nothing approach – we have to bear in mind that the systems underpinning speech and phonology are inextricably linked and interdependent in ways we don’t really understand

Distinctive feature theory• Chomsky & Halle’s system classifies sounds according

to five sets of features:- major classes: sonorant, syllabic,

consonantal- manner: continuant, lateral, nasal- cavity: anterior, coronal, high, low, back,

round- tongue root: tense/lax- laryngeal: voiced/voiceless

Distinctive feature theory

• Attempt to delineate the properties of sounds used contrastively in a particular language

• Features are ‘atomic’ and binary

• Looking at similarities and differences between sounds

• E.g. /k/ /g/ /s/ /n/ /i/consonantal + + + + -vocalic - - - - +stop + + - - -voicing - + - + +nasal - - - + -anterior - - + + +

Distinctive feature theory: clinical implications

• When sound substitutions are compared to target sounds features, similarities and differences can be identified

• Phonological processes can be noted to capture the differences between target and surface realization

• Sound substitutions can be broken down and analyzed

• Can see whether targets and surface realizations share any features

• Can see whether specific error patterns exist

Distinctive feature theories: clinical implications

• Shift in focus from form to function• children acquire features, rather than sounds

(Jakobson 1942)• therapy can facilitate this process, and a

certain amount of generalization should occur

Phonological notation

• A B• / - context• #__• __#• V__V• C__C• __ [+stop]• ø

Analyzing data using DFT• Dataset: Peter aged 4;2

• pen bεn• pet pεt• Ben bεn• face peIt• fat pæt• bus bʌt• dash dæt• fuzz bʌd• cat kæt• bed bεd

• shed dεd• sad dæd• park pa:k• bark ba:k• peas bi:d• boat bәut• kiss kIt• chip tIp• coat kәut• comb gәum

Peter’s rules

• [-voice] [+voice] / ___ [+voice]

• [-stop] [+stop]

Treatment approaches• Articulation therapy – e.g. oral-motor modeling and

drilling• Phonemic approaches – e.g. minimal pairs, in

perception and production• Phonological therapy – e.g. producing more target

sound sequences in more complex linguistic units• Aim: generalization of skills:

– (a) to other levels of representation (e.g. phonological awareness influencing articulations)

– (b) to other environments and contexts spontaneous use of appropriate speech sounds and patterns

Phonological Processes• Hodson 1989: focus on teaching appropriate patterns (not

eliminating inappropriate ones)• Within the target processes, select sounds for which the child is

stimulable• A possible preferred order for tackling error processes:

1. WI single consonants2. WF single consonants in CVC3. Syllable deletions in 2 and 3 syllable words4. Errors relating to velar and alveolar sounds5. S clusters6. Liquids

• This hierarchy takes into account developmental factors, as well as intelligibility issues

• Refer back to nonlinear approaches too: want to impact the whole hierarchy, so target sound errors / classes near the top of the tree

Nonlinear hierarchyRoot

continuantlaterallaryngeal

voice spread glottis constricted glottisplace

labial coronal dorsal

round anterior distributed high back low

nasal

labiodental grooved

consonantalsonorant