Categorical perception of speech by children with specific language impairments.

Previous research has suggested that children with specific language impairments (SLI) have deficits in basic speech perception abilities, and this may be an underlying source of their linguistic deficits. These findings have come from studies in which perception of synthetic versions of meaningless syllables was typically examined in tasks with high memory demands. In this study, 20 children with SLI (mean age = 9 years, 3 months) and 20 age-matched peers participated in a categorical perception task. Children identified and discriminated digitally edited versions of naturally spoken real words in tasks designed to minimize memory requirements. Both groups exhibited all hallmarks of categorical perception: a sharp labeling function, discontinuous discrimination performance, and discrimination predicted from identification. There were no group differences for identification data, but children with SLI showed lower peak discrimination values. Children with SLI still discriminated phonemically contrastive pairs at levels significantly better than chance, with discrimination of same-label pairs at chance. These data suggest that children with SLI perceive natural speech tokens comparably to age-matched controls when listening to words under conditions that minimize memory load. Further, poor performance on speech perception tasks may not be due to a speech perception deficit, but rather to a consequence of task demands.     

False belief understanding in children with specific language impairment

Children's understanding that people's beliefs may differ from reality is an important milestone in cognitive development. Yet the tasks usually used to assess this understanding rely on the comprehension of complex syntax. Children with specific language impairment (SLI) have language abilities that are below age expectations, but their nonlinguistic cognitive abilities--crucial to false belief understanding--are closer to age level. Four conditions of a standard false belief task were administered to 10 children with SLI, 10 children of the same age, and 9 younger children whose language comprehension ability was similar to the children with SLI. The four conditions varied as to their linguistic complexity. The SLI group performed similarly to same-age peers when linguistic complexity was low, but similarly to younger children when linguistic complexity was high. These findings provide evidence that linguistic competence serves as a limiting factor in false belief performance for children with SLI. Educational objectives: Readers will be able to (1) describe different hypotheses regarding the relationship between language and theory of mind development, (2) discuss how linguistic complexity impacts false belief performance for children with SLI, and (3) apply the language/theory of mind relationship when planning intervention.     

Beyond capacity limitations: determinants of word recall performance on verbal working memory span tasks in children with SLI.

Reduced verbal working memory capacity has been proposed as a possible account of language impairments in specific language impairment (SLI). Studies have shown, however, that differences in strength of linguistic representations in the form of word frequency affect list recall and performance on verbal working memory tasks. This suggests that verbal memory capacity and long-term linguistic knowledge may not be distinct constructs. It has been suggested that linguistic representations in SLI are weak in ways that result in a breakdown in language processing on tasks that require manipulation of unfamiliar material. In this study, the effects of word frequency, long-term linguistic knowledge, and serial order position on recall performance in the competing language processing task (CLPT) were investigated in 10 children with SLI and 10 age-matched peers (age 8 years 6 months to 12 years 4 months). The children with SLI recalled significantly fewer target words on the CLPT as compared with their age-matched controls. The SLI group did not differ, however, in their ability to recall target words having high word frequency but were significantly poorer in their ability to recall words on the CLPT having low word frequency. Differences in receptive and expressive language abilities also appeared closely related to performance on the CLPT, suggesting that working memory capacity is not distinct from language knowledge and that degraded linguistic representations may have an effect on performance on verbal working memory span tasks in children with SLI.     

Working memory capacity and language processes in children with specific language impairment.

This study examined the interaction between working memory and language comprehension in children with specific language impairment (SLI), focusing on the function of the central executive component and its interaction with the phonological loop (A. D. Baddeley, 1986) in complex working memory tasks. Thirteen children with SLI and 13 age-matched (age range = 7;0 [years;months] to 10;0) children with typical language development participated. The tasks combined traditional nonword repetition tests and sentence comprehension by using sentences that differed in length and syntactic complexity. The children with SLI exhibited larger processing and attentional capacity limitations than their age-matched peers. Increased word length and syntactic complexity resulted in a large performance decrease in nonword repetition in both groups. There were some variations in the error pattern, which may indicate qualitative differences between the 2 groups. The performance of the children with SLI in nonword repetition, across the different tasks, indicated a limitation in simultaneous processing rather than difficulty in encoding and analyzing the phonological structure of the nonwords. Furthermore, syntactic complexity had a greater effect on performance accuracy than did sentence length.     

Nonword repetition and sentence repetition as clinical markers of specific language impairment: the case of Cantonese.

PURPOSE: Recent research suggests that nonword repetition (NWR) and sentence repetition (SR) tasks can be used to discriminate between children with SLI and their typically developing age-matched (TDAM) and younger (TDY) peers. METHOD: Fourteen Cantonese-speaking children with SLI and 30 of their TDAM and TDY peers were compared on NWR and SR tasks. NWR of IN nonwords (CV combinations attested in the language) and OUT nonwords (CV combinations unattested in the language) were compared. SR performance was compared using 4 different scoring methods. RESULTS: The SLI group did not score significantly lower than the TDAM group on the test of NWR (overall results were TDAM = SLI > TDY). There were nonsignificant group differences on IN syllables but not on OUT syllables. The results do not suggest a limitation in phonological working memory in Cantonese-speaking children with SLI. The SR task discriminated between children and their TDAM peers but not between children with SLI and their TDY peers matched for mean length of utterance. CONCLUSIONS: SR but not NWR discriminates between children with SLI and their TDAM peers. Poorer NWR for English-speaking children with SLI might be attributable to weaker use of the redintegration strategy in word repetition. Further cross-linguistic investigations of processing strategies are required.     

Learning novel words: detail and vulnerability of initial representations for children with specific language impairment and typically developing peers

This study examines the phonological representations that children with specific language impairment (SLI) and typically developing peers (TD) have during the initial process of word learning. The goals of this study were to determine if children with SLI attended to different components of words than peers, and whether they were more vulnerable to interference than peers. Forty 7- and 8-year-old children, half with SLI, took part in a fast mapping, word learning task. In addition to producing the word, there was a mispronunciation detection task that included mispronunciations of the target word in the initial position, final position or that modified the word's syllable structure. Children with SLI showed a different learning profile than peers, demonstrating stronger representations of the word-initial phonemes, but less information about word-final phonemes. They were more prone to interference overall, but especially from word-final foils. Children with SLI did not demonstrate less-defined phonological representations, but did attend to different features than TD children, perhaps in an attempt to compensate for problems learning longer words. The greatest weakness of children with SLI appears to be their susceptibility to interference, particularly for word-final information. Learning outcomes: Readers will be able to: (1) explain what children attend to when learning new words; (2) state the pattern of recognition and production performance for both children with SLI and their typical language peers; and (3) identify specific parts of novel words that are most susceptible to interference in children with SLI.     

Verbal working memory and sentence comprehension in children with specific language impairment.

In this study we examined the influence of verbal working memory on sentence comprehension in children with SLI. Twelve children with SLI, 12 normally developing children matched for age (CA), and 12 children matched for receptive vocabulary (VM) completed two tasks. In the verbal working memory task, children recalled as many real words as possible under three processing load conditions (i.e., no-load condition; single-load condition, where words were recalled according to physical size of word referents; and dual-load condition, where words were recalled by semantic category and physical size of word referents). In the sentence comprehension task, children listened to linguistically nonredundant (shorter) and linguistically redundant (longer) sentences. Results of the memory task showed that the children with SLI recalled fewer words in the dual-load condition than their CA peers, who showed no condition effect. The SLI and VM groups performed similarly overall, but both groups showed poorer recall in the dual-load condition than in the other conditions. On the sentence comprehension task, children with SLI comprehended fewer sentences of both types than the CA children and fewer redundant sentences relative to themselves and to the VM children. Results were interpreted to suggest that children with SLI (a) have less functional verbal working memory capacity (i.e., ability to coordinate both storage and processing functions) than their CA peers and (b) have greater difficulty managing both their working memory abilities and general processing resources than both age peers and younger children when performing a "complex" off-line sentence processing task.     

Basic numeracy in children with specific language impairment: heterogeneity and connections to language.

PURPOSE: This study examined basic numerical skills in children with specific language impairment (SLI) and how well linguistic factors explain the variance in these children's number skills. METHOD: The performance of children with SLI (n=29) was compared with that of typically developing children along a continuum ranging from preschool to 3rd grade (n=20, 47, 40, and 33). This facilitated both linguistic and educational age comparisons. To study number skills within the SLI group more closely, this group was divided into subgroups on the basis of their performance in verbal and nonverbal numerical skills. The performance of the different SLI subgroups on the linguistic and nonverbal reasoning task was analyzed. RESULTS: As a single group, the children with SLI lagged behind their educational age controls in both verbal and nonverbal numerical skills. Subgroup analyses revealed that the ability to retrieve arithmetic facts from the memory was connected to naming fluency, whereas the differences in nonverbal numerical skills were not explained by the cognitive skills measured (nonverbal reasoning skill, verbal short-term memory, vocabulary, comprehension, and naming fluency). CONCLUSIONS: This study demonstrates that children with SLI form a very heterogeneous group in their numerical skills, and thus specific hypotheses concerning the influence of linguistic deficits on developing numerical skills are required. The cognitive components of serial naming speed present a promising domain for further exploration.     

Arithmetic calculation, short-term memory, and language performance in children with specific language impairment: a 5-year follow-up.

A 5-year follow-up of the arithmetic calculation abilities of low-income children with specific language impairment (SLI) is reported. The performance of fourth- and fifth-grade children with SLI was compared with that of typically developing low-income peers and with younger, typically developing low-income children. Short-term memory, language, and arithmetic calculation abilities were assessed. Compared to their age-matched peers, the SLI group exhibited low scores on a number recall task, a marked difficulty with mathematical calculation under timed conditions, and numerous errors when retrieving rote math facts such as 7 x 6 =. Although children with SLI made more written calculation errors than their age-matched peers, they did not differ in the type of errors made. However, strategies used to solve written calculation differed among the groups. Rather than use automatic math fact retrieval, children with SLI were more likely to use counting strategies to solve calculation problems. These findings offer further evidence that children with SLI have difficulty with rote memory. The findings also document the real-world consequences of slow, inefficient memory retrieval in children with SLI.     

Lexical activation during sentence comprehension in adolescents with history of Specific Language Impairment

One remarkable characteristic of speech comprehension in typically developing (TD) children and adults is the speed with which the listener can integrate information across multiple lexical items to anticipate upcoming referents. Although children with Specific Language Impairment (SLI) show lexical deficits (Sheng & McGregor, 2010) and slower speed of processing (Leonard et al., 2007), relatively little is known about how these deficits manifest in real-time sentence comprehension. In this study, we examine lexical activation in the comprehension of simple transitive sentences in adolescents with a history of SLI and age-matched, TD peers. Participants listened to sentences that consisted of the form, Article-Agent-Action-Article-Theme, (e.g., The pirate chases the ship) while viewing pictures of four objects that varied in their relationship to the Agent and Action of the sentence (e.g., Target, Agent-Related, Action-Related, and Unrelated). Adolescents with SLI were as fast as their TD peers to fixate on the sentence's final item (the Target) but differed in their post-action onset visual fixations to the Action-Related item. Additional exploratory analyses of the spatial distribution of their visual fixations revealed that the SLI group had a qualitatively different pattern of fixations to object images than did the control group. The findings indicate that adolescents with SLI integrate lexical information across words to anticipate likely or expected meanings with the same relative fluency and speed as do their TD peers. However, the failure of the SLI group to show increased fixations to Action-Related items after the onset of the action suggests lexical integration deficits that result in failure to consider alternate sentence interpretations.Learning outcomes: As a result of this paper, the reader will be able to describe several benefits of using eye-tracking methods to study populations with language disorders. They should also recognize several potential explanations for lexical deficits in SLI, including possible reduced speed of processing, and degraded lexical representations. Finally, they should recall the main outcomes of this study, including that adolescents with SLI show different timing and location of eye-fixations while interpreting sentences than their age-matched peers.     

Response time in 14-year-olds with language impairment.

PURPOSE: To determine whether children with language impairment were slower than typically developing peers at age 14, and whether slowing, if present, was similar across task domains; whether differences in response time (RT) across domains were the same for children with specific language impairment (SLI) and nonspecific language impairment (NLI); and whether RT performance at age 9 predicted performance at age 14. METHOD: Fourteen-year-old children with SLI (n = 20), NLI (n = 15), and typical development (NLD; n = 31) were administered several linguistic and nonlinguistic speeded tasks. The children had received the same tasks at age 9. RT performance was examined. RESULTS: Both the SLI and the NLI groups were significantly slower than the NLD group in motor, nonverbal cognitive, and language task domains, and there was no significant difference among domains. Individual analyses showed that most, but not all, children with SLI and NLI were slower than the NLD group mean. Slowing at age 9 and age 14 were moderately correlated. CONCLUSIONS: The results suggest that slow RT is a persistent characteristic of many children with language impairment; however, the nature of the relationship between RT and language performance requires further investigation.     

Speed of processing in children with specific language impairment.

The aim of the present study was to investigate the speed with which children with specific language impairment (SLI) respond on a range of tasks. Seventy-seven third-grade children participated in 10 different tasks (involving a total of 41 conditions), including nonlinguistic and linguistic activities. Mean response times (RTs) of children with SLI (n = 29) increased as a function of mean RTs of children with normal language (NLD, n = 29) under each of three different regression models; children with SLI responded more slowly across all task conditions, and also when linguistic and nonlinguistic tasks were analyzed separately. Children with nonspecific language impairment (NLI) were also included (n = 19). The results were similar to those for children with SLI, but the degree of slowing was greater. The results of the group analyses support the hypothesis that speed of processing in children with SLI is generally slower than that of children with normal language. However, some children with SLI do not appear to show deficits of this type.     

Speech disruptions in the narratives of english-speaking children with specific language impairment.

PURPOSE: This study examined the types, frequencies, and distribution of speech disruptions in the spoken narratives of children with specific language impairment (SLI) and their age-matched (CA) and language-matched (LA) peers. METHOD: Twenty 4th-grade children with SLI, 20 typically developing CA children, and 20 younger typically developing LA children were included in this study. Speech disruptions (i.e., silent pauses and vocal hesitations) occurring in the narratives of these children were analyzed. RESULTS: Children with SLI exhibited speech disruption rates that were higher than those of their age-matched peers but not higher than those of their language-matched peers. The difference in disruption rates between the SLI and CA groups was restricted to silent pauses of 500-1000 ms. Moreover, children with SLI produced more speech disruptions than their peers before phrases but not before sentences, clauses, or words. CONCLUSIONS: These findings suggest that there is a relationship between language ability and speech disruptions. Higher disruption rates at phrase boundaries in children with SLI than in their age-matched peers reflect lexical and syntactic deficits in children with SLI.     

Language-specific effects of task demands on the manifestation of specific language impairment: a comparison of English and Icelandic

PURPOSE: Previous research has indicated that the manifestation of specific language impairment (SLI) varies according to factors such as language, age, and task. This study examined the effect of task demands on language production in children with SLI cross-linguistically. METHOD: Icelandic- and English-speaking school-age children with SLI and normal language (NL) peers (n = 42) were administered measures of verbal working memory. Spontaneous language samples were collected in contexts that vary in task demands: conversation, narration, and expository discourse. The effect of the context-related task demands on the accuracy of grammatical inflections was examined. RESULTS: Children with SLI in both language groups scored significantly lower than their NL peers in verbal working memory. Nonword repetition scores correlated with morphological accuracy. In both languages, mean length of utterance (MLU) varied systematically across sampling contexts. Context exerted a significant effect on the accuracy of grammatical inflection in English only. Error rates were higher overall in English than in Icelandic, but whether the difference was significant depended on the sampling context. Errors in Icelandic involved verb and noun phrase inflection to a similar extent. CONCLUSIONS: The production of grammatical morphology appears to be more taxing for children with SLI who speak English than for those who speak Icelandic. Thus, whereas children with SLI in both language groups evidence deficits in language processing, cross-linguistic differences are seen in which linguistic structures are vulnerable when processing load is increased. Future research should carefully consider the effect of context on children's language performance.     

Auditory-visual integration for speech by children with and without specific language impairment.

PURPOSE: It has long been known that children with specific language impairment (SLI) can demonstrate difficulty with auditory speech perception. However, speech perception can also involve the integration of both auditory and visual articulatory information. METHOD: Fifty-six preschool children, half with and half without SLI, were studied in order to examine auditory-visual integration. Children watched and listened to video clips of a woman speaking [bi] and [gi]. They also listened to audio clips of [bi], [di], and [gi], produced by the same woman. The effect of visual input on speech perception was tested by presenting an auditory [bi] combined with a visually articulated [gi], which tends to alter the phoneme percept (the McGurk effect). RESULTS: Both groups of children performed at ceiling when asked to identify speech tokens in auditory-only and congruent auditory-visual modalities. In the incongruent auditory-visual condition, a stronger McGurk effect was found for the normal language group compared with the children with SLI. CONCLUSION: Responses by the children with SLI indicated less impact of visual processing on speech perception than was seen with their normal peers. These results demonstrate that the difficulties with speech perception by SLI children extend beyond the auditory-only modality to include auditory-visual processing as well.     

Social interactions of speech- and language-impaired children.

Social interactions among preschool children were classified into four groups according to language ability: normally developing English, specific language impairment (SLI), speech impairment (SI), and English as a second language (ESL). The children were observed in naturalistic classroom interactions on three occasions. Conversational turns were coded according to initiations and responses, and addressee. The results reveal differences across the groups of children. Normal language peers initiate interactions with each other and have a higher percentage of longer responses; normal language peers were the preferred addressee in peer initiations. In contrast, children with limited communication skills were more likely than their normal language peers to initiate with adults and to shorten their responses or use nonverbal responses. ESL children were the least likely to initiate interactions and were the most likely to be avoided as the recipient of an initiation. The findings are interpreted as evidence that preschool children are sensitive to relative communication skills and make adjustments in their social interactions accordingly. Multiple contributing factors are implicated, including intelligibility, limited linguistic flexibility, limited discourse skills, and self-consciousness about communicative competence.     

Understanding conservation delays in children with specific language impairment: task representations revealed in speech and gesture.

PURPOSE: The authors investigated mental representations of Piagetian conservation tasks in children with specific language impairment (SLI) and typically developing peers. Children with SLI have normal nonverbal intelligence; however, they exhibit difficulties in Piagetian conservation tasks. The authors tested the hypothesis that conservation difficulties may be due to the degree to which children with SLI rely on external perceptual features of the task as opposed to internal cognitive knowledge about transformation. METHOD: Twenty-nine children participated, 12 children with SLI (ages 7;0-10;5) and 17 typically developing peers (ages 5;4-10;9) who were matched either on chronological age (CA) task or on judgments on the conservation task (conservation matched [CM]). Children solved conservation tasks and then explained their reasoning. Explanations produced in speech and gesture were analyzed. RESULTS: In speech, children in the SLI group expressed proportionately fewer internal explanations than the CA group, but a similar proportion of internal explanations as compared with the younger CM group. In gesture, children with SLI did not differ from either CA or CM children. CONCLUSIONS: Children with SLI have weak internal representations of the concept of conservation, similar to those of younger children. Conservation representations appear to be closely related to language skills and verbal working memory.     

Talker discrimination in preschool children with and without specific language impairment

Variability inherently present between multiple talkers can prove beneficial in the context of learning. However, the performance during learning paradigms by children with specific language impairment (SLI) remains below typically developing peers, even when multiple talkers are used. Preschool children with typically developing language (n = 17) and SLI (n = 17) participated in a talker discrimination task. Five different pairings of talkers (same male, different males, same female, different females, male + female) were used to present 50 spoken words. Children with SLI were significantly poorer in discriminating same and different male speakers compared to their typical peers. The present findings demonstrate that preschool children with SLI can experience difficulty distinguishing between talkers. Poor sensitivity to variation in talkers may contribute to poor learning in SLI for contexts where multiple talker input should benefit the learner.     

Do children and adults with language impairment recognize prosodic cues?

PURPOSE: Prosodic cues are used to clarify sentence structure and meaning. Two studies, one of children with specific language impairment (SLI) and one of adults with a history of learning disabilities, were designed to determine whether individuals with poor language skills recognize prosodic cues on par with their normal-language peers. METHOD: Participants were asked to determine whether low-pass filtered sentences matched unfiltered target sentences. Filtered sentences either matched the target sentence exactly or differed on between 1 and 3 parameters that affected the prosodic profile of the sentences. RESULTS: Children with SLI were significantly poorer than their normal peers in determining whether low-pass filtered sentences matched or were different from unfiltered target sentences. The children's performance, measured in terms of response accuracy, deteriorated as the similarities between filtered and unfiltered sentences increased. Adults revealed a pattern of differential reaction time to sentence pairs that reflected their relative degree of similarity. There was no difference in performance accuracy for adults with a history of language/learning disabilities compared with their peers. CONCLUSION: Given that prosodic cues are known to assist language processing, the weak prosodic skills of preschool children with SLI may limit the amount of benefit that these children derive from the presence of prosodic cues in spoken language. That the adult sample did not show a similar weakness in this skill may reflect developmental differences, sampling differences, or a combination of both.     

Differences in the nonword repetition performance of children with and without specific language impairment: a meta-analysis.

PURPOSE: This study presents a meta-analysis of the difference in nonword repetition performance between children with and without specific language impairment (SLI). The authors investigated variability in the effect sizes (i.e., the magnitude of the difference between children with and without SLI) across studies and its relation to several factors: type of nonword repetition task, age of SLI sample, and nonword length. METHOD: The authors searched computerized databases and reference sections and requested unpublished data to find reports of nonword repetition tasks comparing children with and without SLI. RESULTS: Children with SLI exhibited very large impairments in nonword repetition, performing an average (across 23 studies) of 1.27 standard deviations below children without SLI. A moderator analysis revealed that different versions of the nonword repetition task yielded significantly different effect sizes, indicating that the measures are not interchangeable. The second moderator analysis found no association between effect size and the age of children with SLI. Finally, an exploratory meta-analysis found that children with SLI displayed difficulty repeating even short nonwords, with greater difficulty for long nonwords. CONCLUSIONS: These findings have potential to affect how nonword repetition tasks are used and interpreted, and suggest several directions for future research.