Processing Deficits in Children with Language Impairments

Archibald, L.M.D., & Noonan, N. B. (In press). Processing Deficits in Children with Language Impairments. To appear in E.L. Bavin & L. Naigles (eds), The Cambridge Handbook of Child Language, 2^nd ed. Cambridge, UK: Cambridge University Press.

In this chapter, Archibald and Noonan review and evaluate theoretical accounts of specific language impairment (SLI), an unexpected and unexplained developmental delay in the onset or development of oral language in children. Children with SLI receive lower scores than age-matched peers on a variety of measures including many not related to language, but the language deficit in SLI is more severe than deficits in any other area.

The disproportionate linguistic impairment in SLI has resulted in investigations of cognitive mechanisms responsible for processing language-related (or domain-specific) information. Such processes include auditory processing and phonological processing. Many studies have reported SLI deficits on tasks tapping both of these processes.

The findings of impairments on nonlinguistic tasks in SLI groups have lead to a focus on cognitive mechanisms responsible for processing different kinds of information, only some of which may be related to language. These processes are considered domain-general and include attention, working memory, executive functions, and implicit learning.

It may be that the best explanation for the range of mixed findings reported is to consider SLI as resulting from a variety of possible paths. There may be several genetic and environmental factors that could contribute to a child being considered to have (or not have) a language delay. If this is the case, it will be necessary to understand each child’s profile of strengths and weaknesses to understand factors contributing to his/her language impairment profile.

Blogger: Areej Balilah

Phonological deficits in specific language impairment and developmental dyslexia: Towards a multidimensional mode

Ramus, F., Marshall, C.R., Rosen, S., & van der Lely, H.K.J. (2013). Phonological deficits in specific language impairment and developmental dyslexia: Towards a multidimensional model. Brain, 136, 630-645.

Children with specific language impairment (SLI) have an unexpected, developmental delay in the onset or developmental of oral language. Children with developmental dyslexia fail to learn to read at the expected rate despite adequate opportunities. SLI and dyslexia often co-occur leading to questions about distinctions between these impairments. Several views exist regarding the co-existence of these disorders: (1) SLI is a more severe form of dyslexia; (2) Phonological deficits are common to both SLI and dyslexia. Children with SLI also have impairments in other aspects of language (i.e., grammar, word knowledge); (3) The phonological deficits observed in SLI and dyslexia are qualitatively different.

These researchers compared models to fit data from 127 children who had completed measures of grammatical skills, sentence processing, manipulating sounds in words, discriminating sounds in words, and others. The data were explained by 3 factors as follows: (1) nonphonological skills – that is, measures not related to the sound structures of words including grammatical skills and sentence processing, (2) phonological awareness – that is, tasks requiring some sound manipulations in words, and (3) phonological representations – that is, tasks requiring recognition of the sound structures in words. The factors were associated with the different impairment profiles in unique ways: Children with both SLI and dyslexia had low scores on all three factors. Those with SLI-only scored low on the phonological representations and nonphonological skills factor, and those with dyslexia-only on the phonological awareness factor only.

The authors argued that there might be qualitative differences in the phonological deficits that characterize SLI and dyslexia. Those with SLI may have poor phonological representations stored in long-term memory, which makes it difficult for them to complete phonological awareness tasks too. Those with dyslexia, on the other hand, may have intact phonological representations, but have difficulty accessing and manipulating this information. Deficits in nonphonological skills may be characteristic of those with SLI, but also those who struggle with comprehending what they read rather than decoding words.

Blogger: Lisa Archibald

Estes, K. G., & Hurley, K. (2013). Infant‐directed prosody helps infants map sounds to meanings. Infancy, 18(5), 797-824.

Infant directed speech is an exaggerated and repetitive speaking style that adults use when addressing infants. This form of speech encompasses a higher pitch, greater pitch variation and longer durations of speech segments. Infant directed speech supports early language acquisition by helping infants break up the speech they hear into components and helps maintain infant attention. In this paper, the researchers examined how infant directed speech influences an infants’ ability to connect sounds with meanings, specifically words with objects.

In this study, 17-month-old infants were presented with pictures of a novel object while listening to a name for the object. The amount of time the child looked at the novel object was recorded. Typically, infants look at novel objects for a long time at first, but once they become familiar with the stimulus, they spend less time looking (i.e., they become habituated). This method is called a habituation word-learning task. In the first experiment, the infants heard adult directed speech, and in the second, infant-directed speech. A third experiment also used infant directed speech but included different examples of the same word being spoken (different pitch contours and durations of the same word).

The authors found that infants were able to learn the object-label associations when the stimuli were produced using infant directed speech. Infants’ word learning was improved when the labels were produced using infant directed speech that contained variability (Experiment 3).  This suggests that infants form stronger associations between objects and their labels when the sound of the labels contains variability (altered pitch and duration for the same label) such as those produced in Experiment 3. This variability mimics the variability found in naturalistic speech and appears to be critical in an infant’s ability to learn new words. 

Blogger: Monica DaSilva is completing her Masters of Science in Developmental Psychology in the Language and Working Memory Lab. Her work will examine how infant word learning is enhanced by prosodic cues in words (i.e., word stress).

Danahy Ebert, K., & Scott C. M. (2014). Relationships between narrative language samples and norm-referenced test scores in language assessments of school-age children. Language, Speech, and Hearing Services in Schools, 45, 337–350.

Speech-language pathologists rely on a number of tools to complete comprehensive assessments of language abilities in school-age children. Two types of tools are norm-referenced tests and criterion-referenced tests. Norm-referenced tests assess broad language skill and allow clinicians to determine the child’s level of ability by comparing his performance to scores from a large sample of other children. In contrast, criterion-referenced tests offer in-depth information about a smaller set of language skills, but use more naturalistic tasks, such as recounting a narrative.

This study compared the performance of school-age children on a variety of norm-referenced tests and narrative language samples. The authors found that performance on the two types of assessments was more closely related for younger children (6–8 years) than for older children (9–12 years). The study also examined the extent to which the tests agreed on which children where considered to be impaired. Agreement of identification rates between different norm-referenced tests and different aspects of the narrative language samples ranged from 37% to 77%. This showed that some children were identified by both tests, while others were only identified by one type of test.

The authors conclude that age must be considered when selecting criterion-referenced tests because different types of naturalistic language tasks are more appropriate for different ages. They also suggest that clinicians continue to use both types of testing in their assessments in order to gather a wealth of information about each child’s language ability.

Blogger: Laura Pauls, MCISc-SLP

Profile effects in early bilingual language and literacy

Oller, D. K., Pearson, B. Z., & Cobo-Lewis, A. B. (2007). Profile effects in early bilingual language and literacy. Applied Psycholinguistics, 28 (2), 191-230.

English-speaking bilingual and monolingual children perform differently on language tests. The scores of the monolingual group are usually higher, though not always. The pattern of group differences could be related to the aspect of language being investigated, an idea investigated in this paper.

Data were reanalyzed from 620 children in 2^nd and 5^th grades collected as part of a broad-scale study of monolingual English and bilingual Spanish–English learners in Miami. Findings showed no group differences in basic reading (phonics) tasks, but lower oral vocabulary scores for the bilingual Spanish–English than monolingual English learners.

Oller et al. explained this pattern of findings in terms of the “distributed characteristic” of the bilinguals’ knowledge. For bilingual speakers, some vocabulary items may be experienced in one setting and one language while other items are experienced in another setting and the other language. For example, words like ‘sewing’ may be used at home in Spanish, whereas ‘recess’ may occur at school in English. There are so many words being encountered, that the frequency of hearing (at least some) words in both languages may be low. As a result, lexical knowledge is ‘distributed’ across both languages leading but vocabulary level remains lower than monolingual peers in each language.

In contrast, learning two languages requires bilingual children to learn all the phonics of each language. Still, the total number of phonemes across both languages will be small allowing for the child to have frequent experiences with all the phonemes of the languages. Phonemic knowledge, then, is not distributed, but the same across languages. As s result, bilingual and monolingual groups do not differ in phonological analysis skills such as those employed basic reading tasks.

These findings suggest that the distributed characteristic of bilinguals’ knowledge across two languages has important implications for their language and literacy abilities.

Blogger: Areej Balilah.

Executive function profiles in children with and without Specific Language Impairment

Marton, K., Campanelli, L., Scheuer, J., Yoon, J., & Eichorn, N. (2012). Executive function profiles in children with and without Specific Language Impairment. Journal of Applied Psycholinguistics 12(3), 57–73.

Children with an unexpected delay in developing language known as specific language impairment (SLI) have been found to be less accurate on slower in performing a variety of cognitively demanding tasks. This paper investigates the hypothesis that these impairments result from deficits in executive functions, particularly working memory, inhibition, and sustained attention. Inhibition refers to the ability to ignore distracting information (“resistance to interference”), and to prevent previous tasks or routines from interfering with performance on new tasks (“inhibition of prepotent response”).

In this study, children with SLI and groups matched on age and language completed tests of visuospatial short term memory, resistance to interference, inhibition of prepotent response, and sustained attention. The SLI group performed more poorly than age-matched peers on the visuospatial short term memory and resistance to interference. Findings for the sustained attention task were mixed with no differences in the ability of the SLI group to identify correct sequences, but significantly poorer ability to reject incorrect sequences. No group differences were found in the task measuring inhibition of prepotent response.

These researchers provide a theoretically motivated evaluation of executive functions in SLI. One challenge in comparing the results to other studies with the same purpose is that these studies tend to adopt a variety of theoretical perspective and tasks. Further research is needed to examine the role of linguistic and cognitive factors across participant groups and tasks.

Blogger: Laura Pauls is a doctoral student in the LWM lab, and has completed her MClSc in speech language pathology.