Functional deficits in phonological working memory in children with intellectual disabilities

Diagnostik von Lernstörungen: Zeit zum Umdenken

Zusammenfassung. Lernschwierigkeiten beim Erwerb der Schriftsprache oder des Rechnens gehört für ca. ein Drittel aller Grundschulkinder zum schulischen Alltag. Wenn diese Schwierigkeiten länger andauern, wird von Lernschwächen, Lernstörungen oder Lernbehinderungen gesprochen. Die begriffliche Abgrenzung wird aktuell durch verschiedene Klassifikationskriterien in verschiedenen Klassifikationssystemen (ICD-10/11, DSM-5 oder AWMF Leitlinien) sehr erschwert, was Unsicherheiten in der Diagnostik und auch divergierende pädagogische Konsequenzen zur Folge hat. Eine besondere Rolle spielt dabei das sogenannte doppelte Diskrepanzkriterium für die Diagnose einer Lernstörung: Die Leistung eines Kindes muss unter dem nach dem Alter bzw. der Beschulung und der Intelligenz zu erwartenden Niveau liegen. Die Schulleistung muss also erwartungswidrig ausfallen – das betroffene Kind bleibt hinter den für die Klassenstufe typischen Leistungen und auch hinter den eigenen allgemeinen kognitiven Fähigkeiten zurück. Das Kriterium der Diskrepanz der Schulleistung zur Intelligenz wird seit langem kontrovers diskutiert und ist in den Klassifikationssystemen unterschiedlich verankert. Seine Anwendung hat sowohl für die diagnostische als auch für die pädagogische Praxis weitreichende Konsequenzen. Es führt dazu, dass Kinder mit Diskrepanz zwischen Schulleistung und Intelligenz die Diagnose „Lernstörung“ erhalten, Kinder ohne diese Diskrepanz haben eine „Lernschwäche“, beide Gruppen erfahren unterschiedliche schulische und außerschulische Lernförderung. Der vorliegende Beitrag stellt die Berechtigung dieses Kriteriums der Diskrepanz zwischen Schulleistung und Intelligenz anhand empirischer Evidenz in Frage und beleuchtet Konsequenzen sowohl für die bislang gängige Anwendung des doppelten Diskrepanzkriteriums als auch für den Verzicht darauf. Das Fazit dieser Erörterung rät zum Umdenken.

Development of Cognitive Functions and Academic Skills in 9- to 10-year-old Children with Borderline Intellectual Functioning

This longitudinal study examined whether the cognitive and academic development of children (M_age = 10.52 years) with Borderline Intellectual Functioning (BIF), is characterized by developmental delay or atypical development. Cognitive tasks, arithmetic tasks, and reading tasks were administrated during three succeeding years to the BIF group and a Chronological Age-Matched Comparison (CAMC) group. The BIF children displayed weaknesses in relation to all tasks, and slower developmental rates on four arithmetic tasks and word reading. The results provide evidence in support of the developmental delay model as the BIF children overall displayed similar developmental growth and trends as the CAMC group.

Acquisition of Reading and Intellectual Development Disorder

We propose a review of the literature of the studies investigating reading acquisition in intellectual deficiency (ID), with particular focus on the explanatory factors for reading difficulties. Indeed, we explore the role of intellectual efficiency, perceptual abilities, oral language development, phonological processing and memory. The study of reading acquisition in ID is a challenge because of a high degree of heterogeneity in the results which, together with other variables influencing learning and development. This review has allowed us to understand that there are multiple reasons why individuals with ID have difficulty learning to read. More specifically, there is a link between reading skills and certain cognitive skills, such as perception, oral language, phonological processing and working memory.

Introducing the Beatalk technique: using beatbox sounds and rhythms to improve speech characteristics of adults with intellectual disability

BACKGROUND

Individuals with intellectual disability (ID) often demonstrate speech impairments and reduced intelligibility. However, traditional treatment methods, which involve using repetitive verbal and non-verbal exercises, may not be fully suitable for this population. As adults with ID tend to lose interest and motivation facing the demands of a typical speech therapy session, other intervention methods are needed. The current study tested a novel intervention technique, Beatalk, based on practising vocally produced sounds and rhythms, imitating the sounds produced by rhythm machines in an a cappella musical context (i.e., human beatboxing). Human beatboxing may be a particularly effective tool since it involves intense production of speech sounds (phonemes) that can be misarticulated in the presence of speech disorders; it is relatively easy to learn and practice, and is also considered 'fun'.

AIMS

As many of the features of beatboxing make it a promising method for speech therapy, this pioneering study aimed to examine its effectiveness in comparison with a traditional speech therapy.

METHODS & PROCEDURES

Twelve adults with moderate ID and low speech intelligibility (age 24-48 years) participated in a speech therapy group for 6 weeks. Six participants were assigned to the Beatalk (study) group and six to a traditional (control) therapy group. Pre- to post-treatment changes in speech intelligibility and voice measures were assessed.

OUTCOMES & RESULTS

The preliminary data demonstrate that both types of therapy groups resulted in improved performance in articulation accuracy and voice measures, yet the Beatalk technique yielded larger gains.

CONCLUSIONS & IMPLICATIONS

The results present initial evidence for the beneficial effect of the Beatalk technique as an intervention tool for adults with ID. It is an easy-to-use technique in the context of speech therapy, and may enhance verbal communication skills in this population.

Verbal Working Memory Processes in Students With Mild and Borderline Intellectual Disabilities: Differential Developmental Trajectories for Rehearsal and Redintegration

In verbal working memory, two processes serve to retain a fading memory trace: subvocal rehearsal and lexical redintegration. While recent studies on students with mild and borderline intellectual disabilities (MBID) have yielded mixed results on rehearsal, redintegration has not been researched in MBID, yet. Furthermore, most studies have used a group-matched design which, due to methodological constraints, can only distinguish between two different development patterns. Thus, we study both rehearsal and redintegration in students with MBID using developmental trajectories that have greater potential for identifying differential developmental patterns than traditional group-matching approaches. We investigate whether three aspects in working memory develop differently in students with MBID in comparison to typically developing students: (a) the general capacity of the phonological loop, and the effectiveness of (b) rehearsal, and (c) redintegration. We use three different developmental indicators to compare trajectories: chronological age, cognitive capacity, and vocabulary size. N = 210 students (87 students with MBID, 123 typically developing students) completed working memory span tasks with short and long (1- vs. 3-syllable) real words and pseudowords. The effect for word length (short vs. long) measures rehearsal, and the lexicality effect (real words vs. pseudowords) measures redintegration. Results show that developmental trajectories reveal an intercept difference but no slowed rate in rehearsal, and no impairment in redintegration. However, concerning the developmental relation between redintegration and vocabulary size, students with MBID reveal a differential pattern as redintegration appears higher for students with small vocabulary size, but unexpectedly decreases as vocabulary size increases. We conclude that students with MBID show a delayed onset in the development of capacity of the phonological loop and rehearsal and that they do not catch up in their development. Redintegration does not seem to be impaired in relation to age and cognitive capacity. However, the differential relation of redintegration with vocabulary size calls for further research. While impaired subvocal rehearsal appears to be connected to the developmental problems of students with MBID, lexical redintegration seems to be intact in relation to chronological age and cognitive capacity, making it a possible area of strength.

Links Between Short-Term Memory and Word Retrieval in Aphasia

PURPOSE

This study explored the relationship between anomia and verbal short-term memory (STM) in the context of an interactive activation language processing model.

METHOD

Twenty-four individuals with aphasia and reduced STM spans (i.e., impaired immediate serial recall of words) completed a picture-naming task and a word pair repetition task (a measure of verbal STM). Correlations between verbal STM and word retrieval errors made on the picture-naming task were examined.

RESULTS

A significant positive correlation between naming accuracy and verbal span length was found. More intricate verbal STM analyses examined the relationship between picture-naming error types (i.e., semantic vs. phonological) and 2 measures of verbal STM: (a) location of errors on the word pair repetition task and (b) imageability and frequency effects on the word pair repetition task. Results indicated that, as phonological word retrieval errors (relative to semantic) increase, bias toward correct repetition of high-imageability words increases.

CONCLUSIONS

Results suggest that word retrieval and verbal STM tasks likely rely on a partially shared temporary linguistic activation process.

Modeling individual variation in early literacy skills in kindergarten children with intellectual disabilities

In the present study, we investigated (i) to what extent the early literacy skills (phonological awareness, letter knowledge, and word decoding) along with cognitive (nonverbal reasoning, attention, phonological short-term memory, sequential memory, executive functioning) and linguistic (auditory discrimination, rapid naming, articulation, vocabulary) precursor measures of 53 six-year old children with intellectual disabilities (ID) differ from a group of 74 peers with normal language acquisition (NLA) and (ii) whether the individual variation of early literacy skills in the two groups to the same extent can be explained from the precursor measures. Results showed that children with ID scored below the NLA group on all literacy and precursor measures. Structural equation modeling evidenced that in the children with NLA early literacy was directly predicted by phonological awareness, PSTM and vocabulary, with nonverbal reasoning and auditory discrimination also predicting phonological awareness. In children with ID however, the variation in word decoding was predicted by letter knowledge and nonverbal reasoning, whereas letter knowledge was predicted by rapid naming, which on its turn was predicted by attentional skills. It can be concluded phonological awareness plays a differential role in the early literacy skills of children with and without ID. As a consequence, the arrears in phonological awareness in children with ID might put them on hold in gaining proper access to literacy acquisition.

WHAT THIS PAPER ADDS

This paper adds to the theoretical knowledge base on literacy acquisition in a special population, namely children with intellectual disabilities (ID). It addresses factors that influence early literacy learning, which have not been investigated thoroughly in this special and specific group. Furthermore, the children are not tested solely on literacy, but also on cognitive measures that may influence literacy acquisition. Whereas most research in ID focuses on groups with specific syndromes/etiologies, this paper takes a varied group of children with ID into account. The paper also adds to educational insights, since the findings imply that children with ID are able to use phonological pathways in learning to read. Educators could teach these children phonics-based literacy skills tailored to their individual learning needs.

Psychological and Cognitive Aspects of Borderline Intellectual Functioning

Abstract. Borderline Intellectual Functioning (BIF) refers to a global IQ ranging from 71 to 84, and it represents a condition of clinical attention for its association with other disorders and its influence on the outcomes of treatments and, in general, quality of life and adaptation. Furthermore, its definition has changed over time causing a relevant clinical impact. For this reason, a systematic review of the literature on this topic can promote an understanding of what has been studied, and can differentiate what is currently attributable to BIF from that which cannot be associated with this kind of intellectual functioning. Using Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria, we have conducted a review of the literature about BIF. The results suggest that this condition is still associated with mental retardation, and only a few studies have focused specifically on this condition.

Evidence of a Phonological Similarity Effect After Rehearsal Training in Adolescents With Intellectual Disability

A phonological similarity effect (PSE) in adolescents with an intellectual disability (ID) has previously been shown with auditory stimuli, but studies using visual stimuli are scarce. In the case of visually presented items, PSE requires verbal recoding before it appears. Using visual items, we trained 15 participants with ID to use rehearsal strategies. Another group of 13 participants took part in nonstrategic training. In both groups, PSE was tested before and after training. Participants in the strategy-training group, who showed no PSE at pretest, began to show such an effect during the training stage and maintained it until posttest as was observed through microgenetic analysis. Participants with ID showing no PSE with visual material can thus be trained to show this effect through extensive use of cumulative rehearsal. Such training would lead them to recode items verbally, which in turn would make phonological similarities more salient and lead to a PSE.

Working memory studies among individuals with intellectual disability: An integrative research review

BACKGROUND

Integrative research review infers generalizations about a substantive subject, summarizes the accumulated knowledge that research has left unresolved and generates a new framework on these issues. Due to methodological issues emerging from working memory (WM) studies in the population with non-specific intellectual disability (NSID) (N=64) between 1990-2014, it is difficult to conclude on WM performance in this population.

AIM

This integrative research review aimed to resolve literature conflicts on WM performance among individuals with NSID and to identify the conditions/moderators that govern their WM performance compared to controls with Typical development.

METHOD/PROCEDURE

We used the six stages of integrative research review: problem formulation, data collection, evaluation, data analysis, results, interpretation and discussion.

OUTCOMES AND RESULTS

The findings indicate two types of moderators that determine WM performance in the population with NSID: Participants' moderators (criteria for matching the ID and TD groups, CA and MA), and task moderators [the three WM components of Baddeley and Hitch's (1974) model and task load]. Only an interaction between the two moderators determines WM performance in this population. The findings indicate a hierarchy (from more to less preserved) in WM performance of individuals with NSID: The visuospatial tasks, then some of the executive functions tasks, and the phonological loop tasks being less preserved. Furthermore, at a low level of control, the performance of participants with NSID was preserved beyond the modality and vice versa.

CONCLUSIONS AND IMPLICATIONS

Modality and MA/intelligence determine WM performance of individuals with ID. Educators should prepare intervention programs take the impact of the two moderators into account.

Strategic verbal rehearsal in adolescents with mild intellectual disabilities: A multi-centre European study

BACKGROUND

There is a long-held view that verbal short-term memory problems of individuals with intellectual disabilities (ID) might be due to a deficit in verbal rehearsal. However, the evidence is inconclusive and word length effects as indicator of rehearsal have been criticised.

AIM & METHOD

The aim of this multi-site European study was to investigate verbal rehearsal in adolescents with mild ID (n=90) and a comparison group of typically developing children matched individually for mental age (MA, n=90). The investigation involved: (1) a word length experiment with non-verbal recall using pointing and (2) 'self-paced' inspection times to infer whether verbal strategies were utilised when memorising a set of pictorial items.

RESULTS

The word length effect on recall did not interact with group, suggesting that adolescents with ID and MA comparisons used similar verbal strategies, possibly phonological recoding of picture names. The inspection time data suggested that high span individuals in both groups used verbal labelling or single item rehearsal on more demanding lists, as long named items had longer inspection times.

CONCLUSIONS

The findings suggest that verbal strategy use is not specifically impaired in adolescents with mild ID and is mental age appropriate, supporting a developmental perspective.

HPA axis function predicts development of working memory in boys with FXS

The present study examines verbal working memory over time in boys with fragile X syndrome (FXS) compared to nonverbal mental-age (NVMA) matched, typically developing (TD) boys. Concomitantly, the relationship between cortisol-a physiological marker for stress-and verbal working memory performance over time is examined to understand the role of physiological mechanisms in cognitive development in FXS. Participants were assessed between one and three times over a 2-year time frame using two verbal working memory tests that differ in complexity: memory for words and auditory working memory with salivary cortisol collected at the beginning and end of each assessment. Multilevel modeling results indicate specific deficits over time on the memory for words task in boys with FXS compared to TD controls that is exacerbated by elevated baseline cortisol. Similar increasing rates of growth over time were observed for boys with FXS and TD controls on the more complex auditory working memory task, but only boys with FXS displayed an association of increased baseline cortisol and lower performance. This study highlights the benefit of investigations of how dynamic biological and cognitive factors interact and influence cognitive development over time.

Lernschwierigkeiten. Wie man einen pädagogisch-psychologischen Dauerbrenner immer wieder aufs Neue befeuern kann

Zusammenfassung. Ausgehend von definitorischen Überlegungen werden Häufigkeiten und Ursachen von Lernschwierigkeiten thematisiert sowie Erkenntnisse über evidenzbasierte Interventionen. Neben bereichsspezifischen Dysfunktionen gelten für Minderleistungen beim Lesen und in der Rechtschreibung sowie im Rechnen Defizite in bereichsübergreifenden kognitiven Grundfunktionen als ursächlich. Metaanalysen weisen auf eine Überlegenheit symptomspezifischer Interventionsmaßnahmen im Vergleich zu symptomunspezifischen Funktionstrainings hin. Mit dem Konzept der Instruktionsresponsivität (RTI) und einer Hinwendung zu formativer (Lernverlaufs-)Diagnostik existiert eine Alternative zur herkömmlichen Kategorisierungsdiagnostik.

Treating verbal working memory in a boy with intellectual disability

The present case study investigates the effects of a cognitive training of verbal working memory that was proposed for Davide, a 14-year-old boy diagnosed with mild intellectual disability. The program stimulated attention, inhibition, switching, and the ability to engage either in verbal dual tasks or in producing inferences after the content of a short passage had been encoded in episodic memory. Key elements in our program included (1) core training of target cognitive mechanisms; (2) guided practice emphasizing concrete strategies to engage in exercises; and (3) a variable amount of adult support. The study explored whether such a complex program produced "near transfer" effects on an untrained dual task assessing verbal working memory and whether effects on this and other target cognitive mechanisms (i.e., attention, inhibition, and switching) were long-lasting and produced "far transfer" effects on cognitive flexibility. The effects of the intervention program were investigated with a research design consisting of four subsequent phases lasting 8 or 10 weeks, each preceded and followed by testing. There was a control condition (phase 1) in which the boy received, at home, a stimulation focused on the visuospatial domain. Subsequently, there were three experimental training phases, in which stimulation in the verbal domain was first focused on attention and inhibition (phase 2a), then on switching and simple working memory tasks (phase 2b), then on complex working memory tasks (phase 3). A battery of neuropsychological tests was administered before and after each training phase and 7 months after the conclusion of the intervention. The main finding was that Davide changed from being incapable of addressing the dual task request of the listening span test in the initial assessment to performing close to the normal limits of a 13-year-old boy in the follow-up assessment with this test, when he was 15 years old.

The potential for developing a tactile communication system based on Blissymbolics

OBJECTIVE

To be useful for tactile communication, tactile stimuli need to be discriminable from each other. The objective of this study was to determine whether raised-line renderings of Blissymbols have the capacity for being developed into a tactile communication system as measured by their tactile discriminability.

METHODS

Tactile discrimination of Blissymbols was measured by performance on a task in which participants were asked to feel a target raised-line Blissymbol and then to find the target within an array containing the target and raised-line Blissymbol foils.

RESULTS

The vast majority of tactile Blissymbols had tactile discrimination scores of 90% accuracy or better.

CONCLUSION

Most raised-line Blissymbols can be tactilely discriminated from each other, indicating that they have the potential for being developed into a tactile communication system.

Borderline intellectual functioning: a systematic literature review

The literature related to people with borderline intellectual functioning (BIF) was systematically reviewed in order to summarize the present knowledge. Database searches yielded 1,726 citations, and 49 studies were included in the review. People with BIF face a variety of hardships in life, including neurocognitive, social, and mental health problems. When adults with BIF were compared with the general population, they held lower-skilled jobs and earned less money. Although some risk factors (e.g., low birth weight) and preventive factors (e.g., education) were reported, they were not specific to BIF. The review finds that, despite the obvious everyday problems, BIF is almost invisible in the field of research. More research, societal discussion, and flexible support systems are needed.

Specific language impairment: a convenient label for whom?

BACKGROUND

The term 'specific language impairment' (SLI), in use since the 1980s, describes children with language impairment whose cognitive skills are within normal limits where there is no identifiable reason for the language impairment. SLI is determined by applying exclusionary criteria, so that it is defined by what it is not rather than by what it is. The recent decision to not include SLI in DSM-5 provoked much debate and concern from researchers and clinicians.

AIMS

To explore how the term 'specific language impairment' emerged, to consider how disorders, including SLI, are generally defined and to explore how societal changes might impact on use the term.

METHODS & PROCEDURES

We reviewed the literature to explore the origins of the term 'specific language impairment' and present published evidence, as well as new analyses of population data, to explore the validity of continuing to use the term.

OUTCOMES & RESULTS AND CONCLUSIONS & IMPLICATIONS

We support the decision to exclude the term 'specific language impairment' from DSM-5 and conclude that the term has been a convenient label for researchers, but that the current classification is unacceptably arbitrary. Furthermore, we argue there is no empirical evidence to support the continued use of the term SLI and limited evidence that it has provided any real benefits for children and their families. In fact, the term may be disadvantageous to some due to the use of exclusionary criteria to determine eligibility for and access to speech pathology services. We propose the following recommendations. First, that the word 'specific' be removed and the label 'language impairment' be used. Second, that the exclusionary criteria be relaxed and in their place inclusionary criteria be adopted that take into account the fluid nature of language development particularly in the preschool period. Building on the goodwill and collaborations between the clinical and research communities we propose the establishment of an international consensus panel to develop an agreed definition and set of criteria for language impairment. Given the rich data now available in population studies it is possible to test the validity of these definitions and criteria. Consultation with service users and policy-makers should be incorporated into the decision-making process.

Predictors of early literacy skills in children with intellectual disabilities: a clinical perspective

The present study investigated the linguistic and cognitive predictors of early literacy in 17 children with intellectual disabilities (ID) (mean age: 7; 6 years) compared to 24 children with normal language acquisition (NLA) (mean age: 6; 0 years), who were all in the so-called partial alphabetic phase of reading (Ehri, 2005). In each group, children's performances in early literacy skills (phonological awareness, letter knowledge, and word decoding) were assessed, as well as their achievement in linguistic and cognitive measures associated to these skills. The results showed that, notwithstanding the fact that there were no differences in word decoding, children with ID lagged behind on all predictor measures relevant to early literacy skills compared to children with NLA. Moreover, whereas children with NLA showed a regular predictive pathway of early literacy skills, children with ID showed a deviant pattern, in which nonverbal intelligence and rhythmic skills proved to be of major importance. Also letter knowledge appeared to be involved in their early literacy processing. It can be tentatively concluded that in the ID group, children's level of nonverbal intellectual abilities in combination with rhythmic ability proves pivotal in the development of their early literacy skills.

Working memory development in children with mild to borderline intellectual disabilities

BACKGROUND

The purpose of the current cross-sectional study was to examine the developmental progression in working memory (WM) between the ages of 9 and 16 years in a large sample of children with mild to borderline intellectual disabilities (MBID). Baddeley's influential WM model was used as a theoretical framework. Furthermore, the relations between WM on the one hand, and scholastic skills (arithmetic and reading) on the other were examined.

METHOD

One hundred and ninety-seven children with MBID between 9 and 16 years old participated in this study. All children completed several tests measuring short-term memory, WM, inhibition, arithmetic and single word reading.

RESULTS

WM, visuospatial short-term memory and inhibition continued to develop until around age 15 years. However verbal short-term memory showed no further developmental increases after the age of 10 years. Verbal short-term memory was associated with single word reading, whereas inhibition was associated with arithmetic.

DISCUSSION

The finding that verbal short-term memory ceases to develop beyond the age of 10 years in children with MBID contrasts with results of studies involving typically developing children, where verbal short-term memory develops until around age 15 years. This relative early developmental plateau might explain why verbal short-term memory is consistently considered weak in children with MBID.

Phonological short-term memory impairment and the word length effect in children with intellectual disabilities

There is mounting evidence that children and adolescents with intellectual disabilities (ID) of nonspecific aetiology perform poorer on phonological short-term memory tasks than children matched for mental age indicating a structural deficit in a process contributing to short-term recall of verbal material. One explanation is that children with ID of nonspecific aetiology do not activate subvocal rehearsal to refresh degrading memory traces. However, existing research concerning this explanation is inconclusive since studies focussing on the word length effect (WLE) as indicator of rehearsal have revealed inconsistent results for samples with ID and because in several existing studies, it is unclear whether the WLE was caused by rehearsal or merely appeared during output of the responses. We assumed that in children with ID only output delays produce a small WLE while in typically developing 6- to 8-year-olds rehearsal and output contribute to the WLE. From this assumption we derived several predictions that were tested in an experiment including 34 children with mild or borderline ID and 34 typically developing children matched for mental age (MA). As predicted, results revealed a small but significant WLE for children with ID that was significantly smaller than the WLE in the control group. Additionally, for children with ID, a WLE was not found for the first word of each trial but the effect emerged only in later serial positions. The findings corroborate the notion that in children with ID subvocal rehearsal does not develop in line with their mental age and provide a potential explanation for the inconsistent results on the WLE in children with ID.

Measuring quality of life in people with intellectual and multiple disabilities: validation of the San Martín scale

Although there are numerous quality of life instruments in the, field of intellectual disability, most of them are addressed to those, people with the highest levels of functioning, while only a few are, suitable for people with the lowest levels (i.e., people with profound, and severe intellectual disabilities, or people with intellectual and, developmental disabilities and other significant medical conditions or, disabilities). This study provides reliability and validity evidence of, the San Martín Scale, a 95-item Likert scale questionnaire that is, completed by a third-party respondent. The validation sample was composed, of 1770 people from Spain with intellectual and developmental, disabilities that showed extensive or pervasive support needs (8.7% had, mild intellectual disability, 28.25% moderate, 41.6% severe, and 21.4%, profound). The age of the participants ranged between 16 and 77 years old, (M=7.78; SD=12.32). The results suggested that the eight quality of, life domains assessed on the scale are reliable (Cronbach's alpha ranging, from .821 to .933). Confirmatory Factor Analyses provided construct, validity evidences related to the internal structure of the San Martín, Scale, and indicated that the eight first-order factor solution provided, the best fit to the data over unidimensional and hierarchical solutions. Implications of these findings and guidelines for further research are, discussed.

Contributions of phonological awareness, phonological short-term memory, and rapid automated naming, toward decoding ability in students with mild intellectual disability

Reading decoding ability is a fundamental skill to acquire word-specific orthographic information necessary for skilled reading. Decoding ability and its underlying phonological processing skills have been heavily investigated typically among developing students. However, the issue has rarely been noticed among students with intellectual disability who commonly suffer from reading decoding problems. This study is aimed at determining the contributions of phonological awareness, phonological short-term memory, and rapid automated naming, as three well known phonological processing skills, to decoding ability among 60 participants with mild intellectual disability of unspecified origin ranging from 15 to 23 years old. The results of the correlation analysis revealed that all three aspects of phonological processing are significantly correlated with decoding ability. Furthermore, a series of hierarchical regression analysis indicated that after controlling the effect of IQ, phonological awareness, and rapid automated naming are two distinct sources of decoding ability, but phonological short-term memory significantly contributes to decoding ability under the realm of phonological awareness.

Accelerating the early numeracy development of kindergartners with limited working memory skills through remedial education

BACKGROUND

Young children with limited working memory skills are a special interest group among all children that score below average on early numeracy tests. This study examines the effect of accelerating the early numeracy development of these children through remedial education, by comparing them with children with typically working memory skills and early numeracy abilities below average.

METHOD

Selected from a sample of 933 children, children with early numeracy ability below average are assigned into four groups: two intervention groups with limited working memory skills (IL-group) or typical working memory skills (IT-group), and two control groups with limited working memory skills (CL-group) or typical working memory skills (CT-group). All four groups were followed for a period of 1.5 years. Four measurements were carried out.

CONCLUSION

The remedial program proved to be similarly effective for the IL-group and the IT-group. The findings are discussed in the light of several limitations and implications.

Strengths and weaknesses in reading skills of youth with intellectual disabilities

Reading-related skills of youth with intellectual disability (ID) were compared with those of typically developing (TD) children of similar verbal ability level. The group with ID scored lower than the TD group on word recognition and phonological decoding, but similarly on orthographic processing and rapid automatized naming (RAN). Further, phonological decoding significantly mediated the relation between group membership and word recognition, whereas neither orthographic processing nor RAN did so. The group with ID also underperformed the TD group on phonological awareness and phonological memory, both of which significantly mediated the relation between group membership and phonological decoding. These data suggest that poor word recognition in youth with ID may be due largely to poor phonological decoding, which in turn may be due largely to poor phonological awareness and poor phonological memory. More focus on phonological skills in the classroom may help students with ID to develop better word recognition skills.

An examination of specific daily living skills deficits in adults with profound intellectual disabilities

While some researchers have investigated daily living skills deficits in individuals with intellectual disability (ID) as a whole, research on specific daily living skills in a profound ID population is limited. Two hundred and four adults with profound ID residing in two large developmental centers in the southeast portion of the United States were studied. Data were collected on these individuals' daily living skills, utilizing the Vineland Adaptive Behavior Scales (VABS). Three dependent t-tests were conducted comparing the proportion of items endorsed by informants on each of the three subdomains of daily living skills on the VABS (personal, domestic, and community). A significantly larger proportion of Personal Subdomain items were endorsed compared to Domestic or Community Subdomain items. Additionally, participants exhibited a significantly larger proportion of Domestic Skills Subdomain items compared to Community Skills Subdomain items which is consistent with theoretical models suggesting that institutional living may curb broader community skill sets. No gender differences were found in daily living skills. Lastly, individuals between the ages 30 and 39 exhibited significantly more Personal Subdomain skills than individuals who were 60 or older, while participants between the ages 30 and 39 exhibited significantly more Domestic Subdomain skills than individuals between the ages 60 and 69.

Measurement invariance of working memory measures across two Arab cultures

A confirmatory factor analysis was performed to examine the factorial structure of a battery of working memory measures across two Arab cultures (Kuwait and Egypt). The battery of tests was administered to a sample of 384 children: 192 primary-school Kuwaiti children (96 boys, 96 girls; M age = 10.0 yr., SD = 1.0) and 192 primary-school Egyptian children (96 boys, 96 girls; M age = 10.0 yr., SD = 1.2). The multi-group confirmatory factor analysis revealed configural, metric, scalar, and strict invariances across the two cultures. This implies that working memory can be conceptualized similarly by Kuwaiti and Egyptian children and was measured in the same way in both cultures. Both within-groups individual differences and between-groups differences in means reflected differences in the underlying latent construct.

An examination of specific communication deficits in adults with profound intellectual disabilities

Previous research has shown that adults with intellectual disability (ID) evince communication deficits. These communication problems can be divided into problems with receptive, expressive, and written domains. While much research has been devoted to investigating communication deficits in ID in general, scant research has been conducted on communication skills in specific levels of ID. This study examined 204 adults with profound ID residing in two large supports and services centers in the southeastern region of the United States. Data was collected on these individuals' receptive, expressive, and written communication skills using the Vineland Adaptive Behavior Scales (VABS). Three dependent t-tests were conducted comparing the proportion of items endorsed by informants on each of the three communication subdomains (receptive, expressive, and written) with one another. Participants displayed a significantly larger proportion of receptive subdomain items than expressive subdomain items, t(203) = 20.00, p < 0.01, and written subdomain items, t(203) = 20.53, p < 0.01. Additionally, it was found that the individuals exhibited a significantly larger proportion of expressive subdomain items than written subdomain items, t(203) = 10.80, p < 0.01. The implications of these findings are discussed.