DLD

Question 1

DLD definition and rate

Answer 1

Children who have difficulty acquiring their own language for no obvious reason. 2 in 30 (8% of 5-6 years).

Question 2

Bates et al. (1997) early damage to major language areas in brain

Answer 2

Plasticity. No major serious for consequence of language if damage is early enough.

Question 3

DLD behaviour

Answer 3

Problems can be with both language structure and language use. Speaking (expressive)/understanding (receptive)/both.

Question 4

2 areas of common difficulty for DLD

Answer 4

1. Phonology (perceiving and producing speech sounds).
2. Grammar and morphosyntax (appropriate use and understanding of grammatical inflections/comprehension and production of complex sentences).

Question 5

Bishop’s test for the reception of grammar (TROG)

Answer 5

Given a sentence. Respond by selecting the corresponding image. Need syntax (not just understand word meaning).

Question 6

DLD biology (genes)

Answer 6

Substantial genetic influence (MZ = 0.86; DZ = 0.48). Polygenic and complex trait.

Question 7

3 cognitive theories of DLD

Answer 7

1. Modular deficit in dealing with syntax.
2. Poor phonological WM.
3. Procedural learning problems.

Question 8

Rice and Wexler’s extended optional infinitive theory

Answer 8

Modular (domain-specific) deficit in DLD. Very delayed maturation of innate brain system that handles certain grammatical computations.

Question 9

Rice-Wexler task

Answer 9

Tense probe task/finiteness probe task. (Here’s a farmer. Tell me what a farmer does).

Question 10

Rice (2000) DLD performance on Rice-Wexler task

Answer 10

Clear evidence that DLD children have difficulty with morphosyntax. Bimodal distribution.

Question 11

Phonological WM explanation

Answer 11

Syntactic deficits are downstream consequences of phonological memory problems. Inflections marked by morphemes are of ‘weak phonetic substance’ and computing agreement between sentence elements involves a heavy memory load. Difficulty with processing/remembering verbal info leads to unstressed grammatical morphemes at risk.

Question 12

Baddeley et al. (1998) patient PV symptoms

Answer 12

1. Phonological STM limitations.
2. No effect on cognitive function, including language.
3. Inability to learn new words.
   Relatively unimpaired for word-word paired associate learning, but completely impaired for word-nonword paired learning.

Question 13

Gathercole and Baddeley’s (1990) children’s test of nonword repetition (CNRep)

Answer 13

Children had to repeat nonwords with different syllable length. DLD children worse at repeating nonwords compared to both verbal and non-verbal matched control group. Control experiments suggested that deficits not due to faulty perception/articulatory problems. Instead, poor phonological memory that impacts vocab development.

Question 14

2 alternative explanations for poor phonological WM account

Answer 14

1. DLD as a perceptual processing problem.
2. Poor language making phonological STM difficult (rather than the other way around).

Question 15

Procedural deficit hypothesis

Answer 15

DLD caused by impairments in procedural brain system. Declarative learning for learning vocab (arbitrary associations). Procedural learning for learning systems and rules (phonology and grammar).

Question 16

Ullman and Pierpont (2005) DLD relative deficits vs. relative unimpaired

Answer 16

Relative deficits in procedural learning (serial reaction time). Relatively unimpaired in verbal and nonverbal paired-associate learning.

Question 17

Classic serial reaction time task

Answer 17

Unknowingly follow a predetermined sequence. Sequence learning is usually reflected in faster RTs.

Question 18

Hsu and Bishop (2014) DLD performance in serial reaction time task

Answer 18

Slower than age-matched controls. Similar rate of learning as grammar-matched controls. Suggests a developmental delay in implicit procedural learning.

Question 19

Hsu and Bishop (2014) DLD performance in Hebbian learning task

Answer 19

DLD and grammar-match controls had a similar slope of learning. Age-match controls showed a steeper rate of learning.

Question 21

DLD performance on 3 procedural learning tasks

Answer 21

1. DLD did worse than age-match controls on SRT and Hebb tasks.
2. DLD did not do worse on rotor pursuit task.

Procedural learning deficit is not general. Instead seems to be poor implicit learning of sequential information (struggle with extracting higher-order probabilisitic relationships?). No correlations between learning measures and language scores.

Question 22

3 issues with procedural deficit hypothesis

Answer 22

1. Not clear-cut split between declarative vs. procedural learning.
2. Lexical (declarative) learning difficulties in DLD might not be a downstream consequence of procedural learning.
3. Some concerns about reliability of implicit tasks as measures of learning.