An examination of verbal working memory capacity in children with specific language impairment.

This study investigated verbal working memory capacity in children with specific language impairment (SLI). The task employed in this study was the Competing Language Processing Task (CLPT) developed by Gaulin and Campbell (1994). A total of 40 school-age children participated in this investigation, including 20 with SLI and 20 normal language (NL) age-matched controls. Results indicated that the SLI and NL groups performed similarly in terms of true/false comprehension items, but that the children with SLI evidenced significantly poorer word recall than the NL controls, even when differences in nonverbal cognitive scores were statistically controlled. Distinct patterns of word-recall errors were observed for the SLI and NL groups, as well as different patterns of associations between CLPT word recall and performance on nonverbal cognitive and language measures. The findings are interpreted within the framework of a limited-capacity model of language processing.     

Visual working memory span in adults with cochlear implants: Some preliminary findings

ObjectiveNeurocognitive functions, specifically verbal working memory (WM), contribute to speech recognition in postlingual adults with cochlear implants (CIs) and normal-hearing (NH) listener shearing degraded speech. Three hypotheses were tested: (1) WM accuracy as assessed using three visual span measures — digits, objects, and symbols — would correlate with recognition scores for spectrally degraded speech (through a CI or when noise-vocoded); (2) WM accuracy would be best for digit span, intermediate for object span, and lowest for symbol span, due to the increasing cognitive demands across these tasks. Likewise, response times, relating to processing demands, would be shortest for digit span, intermediate for object span, and longest for symbol span; (3) CI users would demonstrate poorer and slower performance than NH peers on WM tasks, as a result of less efficient verbally mediated encoding strategies associated with a period of prolonged auditory deprivation.MethodsCross-sectional study of 30 postlingually deaf adults with CIs and 34 NH controls. Participants were tested for sentence recognition in quiet (CI users) or after noise-vocoding (NH peers), along with WM using visual measures of digit span, object span, and symbol span.ResultsOf the three measures of WM, digit span scores alone correlated with sentence recognition for CI users; no correlations were found using these three measures for NH peers. As predicted, WM accuracy (and response times) were best (and fastest) for digit span, intermediate for object span, and worst (and slowest) for symbol span. CI users and NH peers demonstrated equivalent WM accuracy and response time for digit span and object span, and similar response times for symbol span, but contrary to our original predictions, CI users demonstrated better accuracy on symbol span than NH peers.ConclusionsVerbal WM assessed using visual tasks relates weakly to sentence recognition for degraded speech. CI users performed equivalently to NH peers on most visual tasks of WM, but they outperformed NH peers on symbol span accuracy. This finding deserves further exploration but may suggest that CI users develop alternative or compensatory strategies associated with rapid verbal coding, as a result of their prolonged experience of auditory deprivation.     

Some measures of verbal and spatial working memory in eight- and nine-year-old hearing-impaired children with cochlear implants

OBJECTIVE: The purpose of this study was to examine working memory for sequences of auditory and visual stimuli in prelingually deafened pediatric cochlear implant users with at least 4 yr of device experience. DESIGN: Two groups of 8- and 9-yr-old children, 45 normal-hearing and 45 hearing-impaired users of cochlear implants, completed a novel working memory task requiring memory for sequences of either visual-spatial cues or visual-spatial cues paired with auditory signals. In each sequence, colored response buttons were illuminated either with or without simultaneous auditory presentation of verbal labels (color-names or digit-names). The child was required to reproduce each sequence by pressing the appropriate buttons on the response box. Sequence length was varied and a measure of memory span corresponding to the longest list length correctly reproduced under each set of presentation conditions was recorded. Additional children completed a modified task that eliminated the visual-spatial light cues but that still required reproduction of auditory color-name sequences using the same response box. Data from 37 pediatric cochlear implant users were collected using this modified task. RESULTS: The cochlear implant group obtained shorter span scores on average than the normal-hearing group, regardless of presentation format. The normal-hearing children also demonstrated a larger "redundancy gain" than children in the cochlear implant group-that is, the normal-hearing group displayed better memory for auditory-plus-lights sequences than for the lights-only sequences. Although the children with cochlear implants did not use the auditory signals as effectively as normal-hearing children when visual-spatial cues were also available, their performance on the modified memory task using only auditory cues showed that some of the children were capable of encoding auditory-only sequences at a level comparable with normal-hearing children. CONCLUSIONS: The finding of smaller redundancy gains from the addition of auditory cues to visual-spatial sequences in the cochlear implant group as compared with the normal-hearing group demonstrates differences in encoding or rehearsal strategies between these two groups of children. Differences in memory span between the two groups even on a visual-spatial memory task suggests that atypical working memory development irrespective of input modality may be present in this clinical population.     

The relation between working memory capacity and auditory lateralization in children with auditory processing disorders

ObjectiveAuditory processing disorder (APD) describes a complex and heterogeneous disorder characterized by poor speech perception, especially in noisy environments. APD may be responsible for a range of sensory processing deficits associated with learning difficulties. There is no general consensus about the nature of APD and how the disorder should be assessed or managed. This study assessed the effect of cognition abilities (working memory capacity) on sound lateralization in children with auditory processing disorders, in order to determine how “auditory cognition” interacts with APD.MethodsThe participants in this cross-sectional comparative study were 20 typically developing and 17 children with a diagnosed auditory processing disorder (9–11 years old). Sound lateralization abilities investigated using inter-aural time (ITD) differences and inter-aural intensity (IID) differences with two stimuli (high pass and low pass noise) in nine perceived positions. Working memory capacity was evaluated using the non-word repetition, and forward and backward digits span tasks. Linear regression was employed to measure the degree of association between working memory capacity and localization tests between the two groups.ResultsChildren in the APD group had consistently lower scores than typically developing subjects in lateralization and working memory capacity measures. The results showed working memory capacity had significantly negative correlation with ITD errors especially with high pass noise stimulus but not with IID errors in APD children.ConclusionsThe study highlights the impact of working memory capacity on auditory lateralization. The finding of this research indicates that the extent to which working memory influences auditory processing depend on the type of auditory processing and the nature of stimulus/listening situation.     

The strengths and weaknesses in verbal short-term memory and visual working memory in children with hearing impairment and additional language learning difficulties

Objectives

To compare verbal short-term memory and visual working memory abilities of six children with congenital hearing-impairment identified as having significant language learning difficulties with normative data from typically hearing children using standardized memory assessments.

Methods

Six children with hearing loss aged 8–15 years were assessed on measures of verbal short-term memory (Non-word and word recall) and visual working memory annually over a two year period. All children had cognitive abilities within normal limits and used spoken language as the primary mode of communication. The language assessment scores at the beginning of the study revealed that all six participants exhibited delays of two years or more on standardized assessments of receptive and expressive vocabulary and spoken language.

Results

The children with hearing-impairment scores were significantly higher on the non-word recall task than the “real” word recall task. They also exhibited significantly higher scores on visual working memory than those of the age-matched sample from the standardized memory assessment.

Conclusions

Each of the six participants in this study displayed the same pattern of strengths and weaknesses in verbal short-term memory and visual working memory despite their very different chronological ages. The children’s poor ability to recall single syllable words in relation to non-words is a clinical indicator of their difficulties in verbal short-term memory. However, the children with hearing-impairment do not display generalized processing difficulties and indeed demonstrate strengths in visual working memory. The poor ability to recall words, in combination with difficulties with early word learning may be indicators of children with hearing-impairment who will struggle to develop spoken language equal to that of their normally hearing peers. This early identification has the potential to allow for target specific intervention that may remediate their difficulties.     

Auditory word recognition of nouns and verbs in children with Specific Language Impairment (SLI)

Nouns are fundamentally different from verbs semantically and syntactically, since verbs can specify one, two, or three nominal arguments. In this study, 25 children with Specific Language Impairment (age 5;3-8;2 years) and 50 typically developing children (3;3-8;2 years) participated in an eye-tracking experiment of spoken language comprehension to compare the dynamics of spoken word recognition for nouns and verbs in Spanish. Listeners' eye movements were recorded as they searched an array of pictures in response to hearing a noun or verb. Results showed significant an animacy effect before the word was finished as images that contain more animate entities attracted their looks which suggest an underdevelopment suppression mechanisms inhibition. Moreover, after word finished all the groups showed differences between nouns and verbs. They were faster in recognizing nouns than verbs and one-argument were recognized faster than two- and three-verb arguments whereas. Children with SLI were slower that their controls and especially in the recognition of three-argument verbs. We suggest that this was due to an incomplete argument structure representation that affects processing times. Learning outcomes: (1) As a result of this activity, the participant will be able to describe the differences between adults and children with and without SLI in spoken word recognition of nouns and verbs. (2) As a result of this activity, the participant will be able to describe the animacy effect.     

Performance on verbal and low-verbal false belief tasks: Evidence from children with Williams syndrome

Previous studies that have investigated the relationship between performance on theory of mind (ToM) tasks and verbal abilities in individuals with Williams syndrome (WS) have reported contradictory findings with some showing that language abilities aid performance on ToM tasks while others have found that participants with WS fail these tasks because of their verbal demands. The current study investigated this relationship again comparing performance on a classical change-location task to two newly developed low-verbal tasks, one change-location task and one unexpected content task. Thirty children with WS (aged 5–17;01 years) and 30 typically developing (TD) children (aged between 2;10 years and 9;09 years), who were matched for vocabulary comprehension scores were included in the study. Although performance in the WS group was significantly poorer compared to the TD group on all three tasks, performance was not predicted by their receptive vocabulary or grammatical ability scores. In addition, ToM abilities in both groups depended on the cognitive demands of the task at hand. This finding shows that performance on ToM tasks in WS is not necessarily hindered by their delayed language abilities but rather by the task administered. This could potentially affect the diagnosis of developmental disorders, such as Autism Spectrum Disorders, and comparison of ToM abilities across developmental disorders.Learning outcomes: Readers of this article should be able to (1) describe the current state of theory of mind research in Williams syndrome, (2) identify which cognitive abilities might explain performance on theory of mind tasks in both typically developing children and in children with Williams syndrome, and (3) interpret the importance of task demands when assessing children's theory of mind abilities.     

Phonological representations in children with SLI: a study of French.

The present research examined the quality of the phonological representations of French children with specific language impairment (SLI) and those with normal language development (NLD). Twenty-five children with SLI and 50 children with NLD matched on lexical age level participated in an auditory lexical decision task. The observations gathered in our study can be summarized as follows. First, children with a higher receptive lexical level performed better, and this was true both for children with NLD and children with SLI. Second, both children with NLD and those with SLI were more likely to reject pseudowords resulting from a modification affecting the number of syllables of a word than pseudowords resulting from a slight modification with the number of syllables unchanged. This difference, however, was greater for the children with SLI, who appeared to have much difficulty rejecting pseudowords resulting from slight modifications. Finally, the performance of children with SLI was particularly poor when presented with pseudowords resulting from a slight modification at the beginning or the end of a word. These findings are interpreted as supporting the hypothesis of an under-specification of phonological representations in children with SLI.     

Verb learning in children with SLI: frequency and spacing effects.

PURPOSE: This study explored the effect of frequency (number of presentations), and spacing (period between presentations) on verb learning in children with specific language impairment (SLI). Children learn words more efficiently when presentations are frequent and appropriately spaced, and this study investigated whether children with SLI likewise benefit. Given that these children demonstrate greater frequency dependence and rapid forgetting of recently acquired words, an investigation of frequency and spacing in this population is especially warranted. METHOD: Twenty-four children with SLI (mean age 5;6 [years;months]) and 24 language-matched control children (mean age 3;4) were taught novel verbs during play sessions. In a repeated measures design, 4 experimental conditions combined frequency (12 or 18 presentations) and spacing (all presentations in 1 session, or spread over 4 days). Comprehension and production probes were administered after the final session and 1 week later. RESULTS: Although the children with SLI benefited significantly from frequent and widely spaced presentations, there were no significant effect in the control group. The language-impaired children showed rapid forgetting. CONCLUSIONS: The frequency and spacing of presentations crucially affect the verb learning of children with SLI. A training regimen characterized by appropriately spaced intervals and moderate repetition will optimally benefit lexical learning.     

A functional magnetic resonance imaging investigation of verbal working memory in adolescents with specific language impairment.

This study used neuroimaging and behavioral techniques to examine the claim that processing capacity limitations underlie specific language impairment (SLI). Functional magnetic resonance imaging (fMRI) was used to investigate verbal working memory in adolescents with SLI and normal language (NL) controls. The experimental task involved a modified listening span measure that included sentence encoding and recognition of final words in prior sets of sentences. The SLI group performed significantly poorer than the NL group for both encoding and recognition and displayed slower reaction times for correct responses on high complexity encoding items. fMRI results revealed that the SLI group exhibited significant hypoactivation during encoding in regions that have been implicated in attentional and memory processes, as well as hypoactivation during recognition in regions associated with language processing. Correlational analyses indicated that adolescents with SLI exhibited different patterns of coordinating activation among brain regions relative to controls for both encoding and recognition, suggesting reliance on a less functional network. These findings are interpreted as supporting the notion that constraints in nonlinguistic systems play a role in SLI.     

Language influences on verbal short-term memory performance in Down syndrome: item and order recognition.

Down syndrome is associated with severe deficits in language and verbal shortterm memory, but the causal relationship between these deficits is unclear. The current study therefore investigated the influence of language abilities on verbal short-term memory performance in Down syndrome. Twenty-one individuals with Down syndrome and 29 younger typically developing children were tested on memory for words and nonwords using 2 immediate recognition tasks: an order memory task that was a relatively pure measure of verbal short-term memory and an item memory task that was more sensitive to language ability. Despite having superior vocabulary knowledge to the typically developing children, individuals with Down syndrome were impaired on both order and item tasks. This impairment was particularly marked on the item task, where individuals with Down syndrome showed an atypically large lexicality effect. These results are interpreted in terms of an underlying verbal short-term memory deficit in Down syndrome that is compounded by poor phonological discrimination abilities.     

Effects of lengthening the speech signal on auditory word discrimination in kindergartners with SLI

In the present study, it was investigated whether kindergartners with specific language impairment (SLI) and normal language achieving (NLA) kindergartners can benefit from slowing down the entire speech signal or part of the speech signal in a synthetic speech discrimination task. Subjects were 19 kindergartners with SLI and 24 NLA controls. Results showed both types of speech manipulation to positively influence word discrimination for the entire group of children. Further analysis made clear that the effects were due to the improvement of the scores of the lowest 25% scorers (8 SLI, 3 NLA).

Learning outcomes:

As a result of this activity, the reader will be able to: (1) give an overview on the effects of speech manipulation on discrimination abilities of children with SLI, (2) be able to look with more nuance at the reported effects of the FFW software program.     

Speech perception and verbal memory in children with and without histories of otitis media.

Two groups of children, with (n = 7) and without (n = 7) first-year histories of otitis media, were participants in a longitudinal study that included periodic audiological and medical evaluations during the first year of life. At age 9, these children were tested on a series of speech perception and verbal short-term memory tasks using stimuli of varying degrees of phonetic contrast. Although the otitis-positive group performed less accurately than the otitis-free group, the pattern of errors was the same for the two groups. The performances of the children with and without positive histories of otitis media were negatively affected by an increase in phonetic similarity of the stimulus items. The two groups, however, did not differ on identification or on temporal-order recall when the speech sounds were differentiated by multiple features. These findings provide evidence of subtle, long-term effects of early episodes of otitis media on phonological representations and on working memory.     

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.     

The nature of written language deficits in children with SLI.

Children with specific language impairment (SLI) have associated difficulties in reading decoding and reading comprehension. To date, few research studies have examined the children's written language. The aim of the present study was to (a) evaluate the nature and extent of the children's difficulties with writing and (b) investigate the relationship between oral and written language. Eleven children with SLI were identified (mean age = 11 years) and were compared with a group of children matched for chronological age (CA; mean age = 11;2 [years;months]) and language age (LA; mean CA = 7;3). All groups completed standardized measures of language production, writing, and reading decoding. The writing assessment revealed that the SLI group wrote fewer words and produced proportionately more syntax errors than the CA group, but they did not differ on a measure of content of written language or on the proportion of spelling errors. The SLI group also produced proportionately more syntax errors than the LA group. The relationships among oral language, reading, and writing differed for the 3 groups. The nature and extent of the children's written language problems are considered in the context of difficulties with spoken language.     

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.     

Lexical representations in children with SLI: evidence from a frequency-manipulated gating task.

PURPOSE: This study investigated lexical representations of children with specific language impairment (SLI) and typically developing, chronological age-matched (CA) peers on a frequency-manipulated gating task. The study tested the hypothesis that children with SLI have holistic phonological representations of words, that is, that children with SLI would exhibit smaller effects of neighborhood density on gating durations than CA peers and that children with SLI would be as efficient as CA peers in accessing high-frequency words but that they would differ from their age-matched peers in accessing low-frequency words. METHOD: Thirty-two children (ages 8;5-12;3 [years;months]) participated: 16 children with SLI and 16 typically developing peers matched on age and nonverbal IQ. Children's word guesses after different gating durations were investigated. RESULTS: Contrary to predictions, no group differences in effects of distributional regularity were found: Children in both groups required equally longer acoustic chunks to access words that were low in frequency and came from dense neighborhoods. However, children with SLI appeared to vacillate between multiple word candidates at significantly later gates when compared with children in the CA group. CONCLUSIONS: Children with SLI did not exhibit evidence for phonologically holistic lexical representations. Instead, they appeared more vulnerable to competing words.     

Speed of processing, working memory, and language impairment in children.

PURPOSE: Children with language impairment (LI) often perform below the level of typically developing peers on measures of both processing speed and working memory. This study examined the relationship between these 2 types of measures and attempted to determine whether such measures can account for the LI itself. METHOD: Fourteen-year-old children with LI and their typically developing peers participated in a wide range of processing speed and working memory tasks and were administered a comprehensive language test battery. Confirmatory factor analyses were used to compare 3 nested models designed to examine the dimensionality of the speed and working memory measures. A model that included a general speed factor was also evaluated. RESULTS: The models meeting our evaluation criteria treated speed and working memory as separable factors. Furthermore, nonverbal as well as verbal processing factors emerged from these analyses. Latent variable regression analyses showed that each of the appropriate models accounted for 62% of the variance in the children's concurrent composite language test scores, with verbal working memory making the largest contribution. CONCLUSIONS: These findings shed light on the relationship among different types of processing and suggest that processing factors can contribute to the understanding of language disorders.     

Social difficulties and victimization in children with SLI at 11 years of age.

Specific language impairment is sometimes thought to be associated with concurrent difficulties in the area of social and behavioral development (N. Botting and G. Conti-Ramsden, 2000; D. P. Cantwell and L. Baker, 1987; M. Fujiki, B. Brinton, and C. Todd, 1996; S. Redmond and M. Rice, 1998). The present study follows a group of 242 children, initially studied at age 7 years when they attended language units in England, and assesses their social and behavioral status at age 11 years. In total, 64% of the children were found to have scores on the Rutter behavioral questionnaire (M. Rutter, 1967) of 9 or above (clinical threshold); 34% scored over the threshold for the Strengths and Difficulties questionnaire (R. Goodman, 1997); and 39% scored below average on the Peer Competence subscale of the Harter Perceived Competence Scale (S. Harter and R. Pike, 1984). On further analysis, these generalized difficulties were characterized mainly by poor social competence. In addition, 36% of the cohort were at risk of being regular targets for victimization compared to 12% of a comparison sample of typically developing peers. Few associations were found between social outcome and other measures, including nonverbal intelligence, overall linguistic skill, gender, and longitudinal measures taken previously. Importantly, however, pragmatic language difficulties measured on the Children's Communication Checklist (D. V. M. Bishop, 1998) were most strongly related to poor social outcome and to expressive language related to victimization.