Strengths and weaknesses in executive functioning in children with intellectual disability

Do Motor-Cognitive and Motor-Motor Dual-Task Training Differently Affect Dual-Task Interference in Individuals With Intellectual Disability?

This study explored the effect of different dual-task (DT) training programs on DT interference in adults with intellectual disability. Center-of-pressure (CoP) mean velocity in single-task (ST) and cognitive-DT conditions and the Timed Up-and-Go Test (TUGT) during ST, cognitive-DT, and motor-DT conditions were assessed before and after intervention in a cognitive-motor training group, a motor-motor training group, and a control group. Before training, CoP mean velocity and TUGT time increased (p < .001) in DT compared with the ST condition. After training, the CoP mean velocity values remained unchanged (p = .07) in DT compared with the ST condition among the cognitive-motor training group. Furthermore, compared with the ST condition, no increase (p = 1) was reported in the TUGT time during the cognitive-DT condition for the cognitive-motor training group and during the motor-DT for the motor-motor training group (p = .12). The effect of DT training on DT interference depends on the training modality.

Relationships between Sensory Processing and Executive Functions in Children with Combined ASD and ADHD Compared to Typically Developing and Single Disorder Groups

The prevalence of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) is increasing, with a tendency for co-occurrence. Some studies indicate a connection between atypical sensory processing and executive function. This study aims to explore the distinctive etiology of executive function deficits in children with ASD+ADHD by investigating the relationship between sensory processing and executive function, comparing children with ASD, ASD+ADHD, ADHD, and typically developing children (TD).

METHOD

Sensory Profile 2 (SP-2) and Behavior Rating Inventory of Executive Function 2 (BRIEF-2) were measured in 120 school-aged children. The results of the above scales were compared across these four groups, and correlation and regression analyses between BRIEF2 and SP2 were conducted.

RESULTS

Our research revealed varying levels of atypical sensory processing and executive function anomalies across the three neurodevelopmental disorder groups compared to the TD group. The ASD+ADHD group showed particularly significant differences. The heightened emotional problems observed in ASD+ADHD children may be associated with more prominent atypical sensory processing. Variance analysis of inhibitory function revealed differences between ASD+ADHD and ADHD children, suggesting distinct etiological mechanisms for attention issues between ASD+ADHD and ADHD.

CONCLUSIONS

ASD+ADHD represents a phenotype distinct from both ASD and ADHD. Special consideration should be given to interventions for children with ASD+ADHD. The results of this study may offer a new perspective on understanding the occurrence of ASD+ADHD and potential individualized intervention methods.

Exploration of a somatosensory interactive assessment tool for children with intellectual disabilities

Based on the functional assessment concept and embodied assessment requirements, the present study aimed to design and develop an assessment tool for children with intellectual disabilities with the help of somatosensory interactive (SI) technology. The sample in this study consisted of 73 children with intellectual disabilities and 70 children with typical development. Data were collected through three SI tasks, four traditional executive function tasks, and user experience interviews to analyse the effectiveness of the SI assessment tool. The results showed that the SI assessment tool had good scale validity, discriminant validity, and the ability to identify intellectual disabilities. Children preferred SI tasks and showed higher involvement and more positive emotions. The SI tool with three SI tasks is a more scientific, effective, and advanced tool for assessing children with intellectual disabilities.

Effects of a physical education intervention on attention and inhibitory control in Ecuadorian children with intellectual disabilities

Background: Studies on physical activity interventions indicated a facilitative effect on cognitive performance in persons with intellectual disabilities; however, research is scarce, especially in low/middle-income countries. Aim: We explored the effects of a 6-week enriched physical education program on inhibitory control and attention functions in Ecuadorian children with intellectual disabilities. Methods: Thirty children with mild intellectual disabilities (10-14 years old) were randomly assigned to an intervention or control group. Before and after the intervention, attention and inhibitory control were measured using computer-based nonverbal tasks. Results: The findings showed significantly more accurate and faster responses in the vigilance task in the intervention group than in the controls. There were no significant intervention-related changes in inhibitory control; however, there were more prominent accuracy tendencies toward improvement in the intervention group. Conclusions: Results provide evidence of the potential of physical activity programs to enhance attention in this population, which could serve as a mediator for inhibitory control.

The associations among executive planning, self-determination, and quality of life in adolescents with intellectual disability

BACKGROUND

Skills such as planning and problem solving that are required in self-determination can be cognitively demanding. It has not yet been examined whether executive functions and intelligence are associated with levels of self-determination in individuals with intellectual disability (ID), and how that is related to quality of life (QoL). This study examined the associations among executive functions, intelligence, self-determination, and QoL in adolescents with ID.

METHODS

Seventy-nine adolescents aged between 17 and 20 years with mild ID participated in the study. Executive functions were assessed by experimental tasks. Non-verbal IQ and survey data regarding QoL and self-determination capacity were collected from the participants.

RESULTS

In a regression model with QoL as the dependent variable, only executive planning and self-determination capacity (but not working memory, inhibition and IQ) were significant predictors of QoL. Two mediation models were tested based on the hypotheses, literature and current findings. Model 1 revealed that executive planning had a negative direct effect on QoL when the mediator, self-determination capacity, was held constant. Model 2 indicated that the significant association between self-determination and QoL was not mediated by executive planning.

CONCLUSIONS

The findings highlighted the crucial significance of self-determination, in comparison with executive functions and intelligence, for improving the QoL in adolescents with ID. Importantly, higher executive planning skill was even associated with lower QoL if self-determination was not concurrently strengthened. These findings carry implications for the design of education and intervention programmes aimed at improving QoL of adolescents with ID.

The Perfect Match! A Review and Tutorial on Issues Related to Matching Groups in Investigations of Children with Neurodevelopmental Conditions

Research concerned with children and young people who have neurodevelopmental disabilities (ND) in relation to early language acquisition usually involves comparisons with matched group(s) of typically developing individuals. In these studies, several important and complex issues need to be addressed. Three major issues are related to: (1) the choice of a variables on which to carry out group matching; (2) recruiting children into the study; and (3) the statistical analysis of the data. To assist future research on this topic, we discuss each of these three issues and provide recommendations about what we believe to be the best course of action. To provide a comprehensive review of the methodological issues, we draw on research beyond the topic of early language acquisition. Our overall aim is to contribute to research that considers questions about delay or differences in development patterns of development and about identifying potentially causal variables.

Associations between executive functions, intelligence and adaptive behaviour in children and adolescents with mild intellectual disability

Background: The purpose of this study was to explore the role of everyday executive functions in relation to intelligence and adaptive behaviour in children and adolescents with mild intellectual disability. Method: A group of children and adolescents, previously diagnosed with mild intellectual disability were assessed according to intelligence, everyday executive functions and adaptive behaviour. The association between everyday executive functions and intelligence was examined, and it was explored whether intelligence or everyday executive functions would best predict adaptive behaviour. Results: Adaptive behaviour was significantly predicted by executive functions, but not by intelligence. Nor was intelligence significantly related to everyday executive functions in this group. Conclusions: Although fundamental in diagnosing intellectual disability, intelligence cannot predict adaptive behaviour. Assessing everyday executive functions and adaptive behaviour, as well as acknowledging the strong association between them, provides valuable information in the process of optimizing developmental support for children and adolescents with mild intellectual disability.

ADHD and ASD symptoms in young males with fragile X syndrome: associations with early trajectories of inhibitory control

Inhibitory control (IC), the ability to suppress inappropriate responses, emerges late in the first year of life and improves across typical development, concurrent with brain maturation. The development of IC is critical to various social-emotional and behavioral functions, with IC difficulties being linked to numerous neurodevelopmental disorders, including attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Fragile X syndrome (FXS) is a single-gene disorder characterized by IC difficulties, and elevated rates of ADHD and ASD, making it a useful model for understanding the early development and consequences of IC. In this longitudinal study, we characterized IC trajectories across multiple time points between 16 and 71 months of age in young males with FXS (n = 79) relative to neurotypical (NT) controls (n=49). To explore the association between behavioral outcomes and IC, we identified a subsample of 50 children with longitudinal IC data and an outcome assessment for ADHD and ASD symptoms at age 5 (FXS: n = 26, NT: n = 24). Results indicated that, compared to their NT peers, young males with FXS exhibit differences in IC as early as 24 months, with group differences increasing through age 5. Additionally, we determined that lower IC levels at 24 months were associated with later ADHD symptoms and a decreasing slope in IC over time was associated with later ASD symptoms in male children with FXS. These findings help refine early developmental phenotypes of FXS and highlight IC as a potential target for early detection and intervention of ASD and ADHD symptoms in male children with FXS.

Dual-Task Training Effects on the Cognitive-Motor Interference in Individuals with Intellectual Disability

This study explored the effect of dual task (DT) training compared to single task (ST) training on postural and cognitive performances in DT conditions in individuals with intellectual disability (ID). Postural sways and cognitive performances were measured separately and simultaneously before and after 8 weeks in the ST training group (STTG), the DT training group (DTTG) and the control group (CG) that did not received any training. Before training, postural sways and cognitive performances were higher in the DT condition compared to ST one in all groups. After training, postural sways were higher in the DT condition compared to the ST only in the STTG and the CG. The cognitive performance increased after training only in the DTTG.

Executive Function in Autism: Association with ADHD and ASD Symptoms

There is substantial comorbidity between autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD), and there are well-documented executive functioning (EF) deficits in both populations. An important question concerns whether EF deficits in children with ASD are related to severity of ASD, ADHD, or both. We examined ADHD and ASD symptoms in relation to ratings of EF in the home and classroom. The sample comprised 64 children (55 males) diagnosed with ASD (mean age = 9.26 years; mean FSIQ = 92). Analyses indicated that parent and teacher ratings of EF (except Shift and Emotional Control) were consistently related to ADHD symptom severity, but not to ASD severity. Thus, functioning in the domains of Shift and Emotional control appear relatively spared, whereas performance in all other EF was impaired in relation to ADHD symptoms.

[Formula: see text] A review of procedural and declarative metamemory development across childhood

Metamemory is a component of metacognition that includes both the knowledge of factors that affect memory (i.e. declarative metamemory) and knowledge and application of factors in one's own learning and recall performance (i.e. procedural metamemory). The current paper aims to provide a comprehensive review of studies examining metamemory ability development from preschool into adolescence in order to improve the understanding of metamemory, its developmental course, and the available assessment methods. We examined the developmental trajectory of procedural and declarative metamemory abilities for both typically developing children and clinical populations. We found procedural metamemory abilities emerge around 4 to 5 years old, and significantly improve across childhood and into adulthood, although less is known about metamemory development across adolescence in typically developing children. Additionally, metamemory abilities vary significantly based on clinical pathology, although relatively fewer studies have examined these abilities in children with neurodevelopmental disorders or other neurologic conditions, such as acquired brain injury. The methods of metamemory assessment varied significantly across studies as well, indicating a need for a standardized metamemory measure, which would have high utility for clinical care.

Effects of intellectual disability and attachment on hostile intent attribution bias

Understanding hostile intent attribution (HIA) seems important for prevention of problems in social adaptation. This study aimed to explore whether HIA in childhood is determined by both a cognitive factor (i.e. intellectual disability) and an affective factor (i.e. attachment representations). One hundred and eight 8- to 12-year-old children (54 with intellectual disability and 54 with typical development) passed the Attachment Story Completion Task and the Intention Attribution Test for Children. Results indicated that in ambiguous situations, attachment disorganization was associated with HIA, whereas intellectual disability was not. In nonintentional situations, both attachment hyperactivation and intellectual disability were linked with HIA. These results highlight the importance of helping children develop organized attachment representations and optimal activation of their attachment system to prevent social maladaptation.

Characteristics of shifting ability in children with mild intellectual disabilities: an experimental study with a task-switching paradigm

BACKGROUND

Shifting enables flexible switch between tasks or mental sets. It is a component of the executive function that plays critical roles in human behaviour control. However, shifting ability in individuals with intellectual disability (ID) has not been well clarified because of the use of intellectually demanding tasks in previous studies. The present study invented a novel shifting task with minimal intellectual demands and aimed to clarify the characteristics of shifting in adolescents with ID.

METHODS

Adolescents with ID (n = 21) and chronological-age-matched (n = 10) and mental-age-matched controls (n = 33) performed a novel shifting task with simple rule switching (i.e. change in direction). Analyses focused on the switch cost or the increase in the reaction time associated with rule switching.

RESULTS

Two subtypes of adolescents with ID were found with respect to the switch cost: one that lacks it and another with an increased switch cost. The lack of a switch cost was unique to the subgroup adolescents with ID and was not indicated in the control group.

CONCLUSIONS

The present study indicated that shifting in adolescents with ID does not depend solely on their intellectual function and is highly heterogeneous. This finding further implies that executive functions, including shifting, must be evaluated separately from their intellectual functions.

Serious Games for Executive Functions Training for Adults with Intellectual Disability: Overview

(1) Background: Throughout the history of medical and psychology practice, specialists have worked to improve the quality of treatment and rehabilitation, which has led to the emergence of concepts such as serious games. These tools focus on different areas of intervention procedures, one of which is to help people with intellectual disability (ID). Individuals with ID have problems with executive functions (EFs), which are related to adaptive functioning. Recent studies showed that serious games positively impact cognitive, social, and communication skills in people with ID. The purpose of this study is to analyze the solutions that have been found in EF training for adults with ID in recent years, evaluating them with a number of key parameters and identifying the features and possible problems in the further development of our system. (2) Methods: A review was conducted starting with 573 articles in English related to serious games and selected from studies that had been published since 2015. Finally, 10 were examined in detail as they focused on EFs in adults with ID. They were searched in seven major databases ("Association for Computing Machinery" (ACM), IEEE Xplore database, DBLP computer science bibliography, Google Scholar, PubMed, SCOPUS, and PsycInfo). (3) Results: It was determined that the most frequent EFs referred to in the studies analyzed were planning and decision-making, followed by working memory and social cognition, behavioral regulation, flexibility, and inhibition capacity. The basic approach to the creation of support systems was also analyzed in terms of technical and program execution. The trend results' analysis evidenced improvements in EFs, even though they were not significant. This comprehensive technique enabled the identification of the main features and aspects to be taken into account for further development of our system.

Neurocognitive Artificial Neural Network Models Are Superior to Linear Models at Accounting for Dimensional Psychopathology

In recent years, there has been debate about the optimal conceptualisation of psychopathology. Structural models of psychopathology have been developed to counter issues, including comorbidity and poor diagnostic stability prevalent within the traditional nosological approach. Regardless of the conceptualisation of psychological dysfunction, deficits in neurocognitive abilities have been claimed to be an aetiological feature of psychopathology. Explorations of the association between neurocognition and psychopathology have typically taken a linear approach, overlooking the potential interactive dynamics of neurocognitive abilities. Previously, we proposed a multidimensional hypothesis, where within-person interactions between neurocognitive domains are fundamental to understanding the role of neurocognition within psychopathology. In this study, we used previously collected psychopathology data for 400 participants on psychopathological symptoms, substance use, and performance on eight neurocognitive tasks and compared the predictive accuracy of linear models to artificial neural network models. The artificial neural network models were significantly more accurate than the traditional linear models at predicting actual (a) lower-level and (b) high-level dimensional psychopathology. These results provide support for the multidimensional hypothesis: that the study of non-linear interactions and compensatory neurocognitive profiles are integral to understanding the functional associations between neurocognition and of psychopathology.

A systematic review and narrative synthesis of mental imagery tasks in people with an intellectual disability: Implications for psychological therapies

Mental imagery is recognised for its role in both psychological distress and wellbeing, with mental imagery techniques increasingly being incorporated into psychological interventions. In this systematic review and narrative synthesis (PROSPERO 2021: CRD42021240930), we identify and evaluate the evidence base for the phenomenon and phenomenology of mental imagery in people with intellectual disabilities, to ascertain the applicability of such interventions for this population. Electronic searches of nine databases and grey literature identified relevant publications. Two reviewers independently assessed titles and abstracts of retrieved records (n = 8609) and full-text articles (n = 101) against eligibility criteria. Data were extracted and quality appraised. Forty-onepapers met our eligibility criteria. The quality and designs were variable. Mental imagery was facilitated through ensuring participants understood tasks, providing opportunity to rehearse tasks (including using concrete prompts) and using scaffolding to help participants elaborate their responses. People with intellectual disabilities can engage with mental imagery, with appropriate adaptations, although the associated phenomenology has not been thoroughly investigated. Mental imagery interventions may be useful for people with intellectual disabilities with appropriate modifications.

Caregiver-reported executive functioning and associated adaptive and challenging behaviour in children with histories of developmental delay

BACKGROUND

Deficits in executive functioning (EF) have been measured in individuals with developmental disabilities, such as autism spectrum disorder and attention-deficit/hyperactivity disorder, through the use of behaviour rating scales and performance-based assessment. Associations between EF and variables such as challenging and adaptive behaviour have been observed; however, limited research exists on EF profiles in children with heterogeneous developmental delay or with intellectual disability (ID) or the impact of EF on adaptive and challenging behaviour with this population.

METHODS

The present study sought to examine the EF profile of 93 children (75 male and 18 female) previously identified with developmental delay in early childhood. EF was assessed using the Behaviour Rating Inventory of Executive Function, Second Edition (BRIEF-2). Children were categorised into an ID group (n = 14) or no ID group (n = 79) based on scores from cognitive and adaptive behaviour assessments. EF profiles were investigated and compared by group. In addition, the impact of EF on both adaptive behaviour and challenging behaviour was measured using hierarchical linear regressions.

RESULTS

Statistically significant differences in caregiver-reported EF were not observed between groups; however, both the ID and the no ID group scores were elevated as reported by their caregivers. For the overall sample, caregiver-EF accounted for significant variance in both adaptive (22%) and challenging (68%) behaviour after accounting for child age and sex.

CONCLUSIONS

Results indicated deficits in EF for children with and without ID. The significance of EF was accounted for in both adaptive and challenging behaviour for all children in the sample. Future research could elucidate the role of adaptive and challenging behaviour in understanding EF variability among children with histories of developmental delay.

Working memory training in children with borderline intellectual functioning and neuropsychiatric disorders: a triple-blind randomised controlled trial

BACKGROUND

Poor working memory, lower IQ and maladaptive behaviour form a triple disability known to have negative effects on the academic and social development of children with borderline intellectual functioning (BIF; IQ: 70 < IQ < 85) and neuropsychiatric disorders [attention-deficit hyperactivity disorder (ADHD) and/or autism spectrum disorder (ASD)]. Treatment possibilities for these children are scarce and hardly evidence based. This study primarily investigated whether adaptive computerised working memory training (WMT) may lead to significantly more improvement on a non-trained visuospatial WM task compared with a non-adaptive control WMT (placebo) in children with BIF and neuropsychiatric disorders. As secondary outcome measures, we used the scores on several non-trained neuropsychological near-transfer and far-transfer tasks as well as behavioural measures.

METHOD

We conducted a triple-blind placebo-controlled randomised clinical trial in 72 children (aged 10;0-13;11 years, 53 boys, 19 girls) with BIF and comorbid neuropsychiatric disorders (ADHD = 37, ASD = 21, both = 14) that were referred to child and adolescent psychiatry care, between May 2012 and March 2019. Children completed the Dutch version of Cogmed WMT, either the adaptive training version or the non-adaptive placebo version, 25 sessions (30-45 min a day), for 5 weeks. The primary outcome measure was the score on a non-trained visuospatial working memory task. The primary outcome was measured before and directly after 5 weeks of WMT and again 6 months after training.

RESULTS

A total of 375 children were screened for eligibility and 72 were randomised. No significantly higher levels of improvement over time were found on our primary outcome measure in the experimental WMT group compared with the placebo control WMT, nor in the secondary (near-transfer and far-transfer tasks) or tertiary (behavioural measures) outcome measures. However, this study did show changes over time for these measurements for both the experimental and placebo conditions.

CONCLUSIONS

This study was unable to document superior training effects over time of an adaptive WMT in children with BIF and neuropsychiatric disorders, compared with a placebo (non-adaptive) WMT. The objectively documented changes over time in the non-adaptive WMT arm suggest that these children with persistent impairments in WM may benefit from a structured learning environment that is associated with improvement of neurocognitive functioning and coping strategies. Further research is needed to examine which elements of cognitive training may be useful for which specific patients and to study long-term effects of training.

Neurocognitive functioning of children with mild to borderline intellectual disabilities and psychiatric disorders: profile characteristics and predictors of behavioural problems

BACKGROUND

The aim of the current study was twofold: first, to uncover a neurocognitive profile of normative and relative strengths and weaknesses that characterises an extremely vulnerable group of children with mild to borderline intellectual disabilities (MBID) and co-morbid psychiatric disorders, and second, to investigate the relevance of these neurocognitive functions explaining internalising and externalising symptoms.

METHOD

We recruited 45 children (M_age  = 9.5, SD_age  = 1.7; range 6-13 years) with MBID (Full-Scale IQ 50-85) and at least one psychiatric disorder. Neurocognitive functioning was examined utilising the Wechsler Intelligence Scale for Children - Fifth Edition (WISC-V) indices and the Cognitive Task Application (COTAPP), a comprehensive computerised self-paced task designed in such a manner that 'g' (an overall tendency of children with MBID to execute tasks with a slower reaction time and a higher error rate) has been corrected for in the administration of the task (i.e. completely self-paced) and in the operationalisation of outcome measures. Behavioural problems were measured using the CBCL and TRF. One-sample t-tests and binomial tests were carried out to compare performance with normative data. Regression analyses were used to examine the relationship between neurocognitive parameters and mental health.

RESULTS

Compared with normative data, very small to very large effect sizes were found, indicating clear heterogeneity amongst neurocognitive domains relevant for children with MBID. Two prominent neurocognitive weaknesses emerged: processing speed - characterised by slowness and unstableness combined with a high drift rate and delayed processing of the previous trial, particularly under higher cognitive demands - and working memory - in terms of a weaker central executive and 'slave' systems to temporarily store information. Both domains were not clearly predictive of internalising or externalising problems.

CONCLUSION

Children with MBID and psychiatric disorders are hampered by a strongly diminished processing speed and working memory capacity, together resulting in an overall limited processing capacity that may underlie the general developmental delays on domains that depend on fast and parallel processing of information (i.e. language, reading, mathematics and more complex forms of social cognition). Neurocognitive vulnerabilities are neither necessary nor sufficient to explain internalising and externalising problems; rather, a mismatch between the support needs and adaptations these children need, arising from their diminished processing capacity, and the inadequacy of the environment to compensate for this vulnerability may be of relevance.

A meta-analysis of the executive function components inhibition, shifting, and attention in intellectual disabilities

BACKGROUND

Executive function is a concept for higher-order cognitive functions, which have the role of controller and modulator of cognitive abilities. The consensus in the literature is that people with an intellectual disability perform significantly lower on executive function tasks than groups matched on chronological age. The comparison with groups matched on mental age is less clear. Therefore, the objective of this meta-analysis was to investigate to what extent executive function is impaired in people with intellectual disability compared with a typically developing control group matched on mental age. It was also investigated if the executive function component and intellectual disability aetiology moderated the effect.

METHODS

Eligibility criteria were participants with intellectual disability (IQ ≤ 75) without a dual diagnosis; a comparison group matched on mental age; executive function outcome reported in a group comparison study design with n ≥ 10. Working memory tasks and ratings of executive function were not included. The literature search yielded 6637 potentially interesting articles. Twenty-six studies (with 99 effect sizes) including 1395 participants were included in the quantitative synthesis.

RESULTS

A multilevel random-effects meta-analysis found that people with intellectual disability performed statistically significantly lower than the mental age-matched group on the executive function tasks, g = -0.34, 95% confidence interval = [-0.53, -0.16]. However, the heterogeneity between effect sizes was large. The intellectual disability aetiology moderator was significant, but it only reduced the heterogeneity marginally.

CONCLUSION

The overall conclusion is that individuals with an intellectual disability have more problems with executive function tasks than mental age-matched controls. Limitations are the large unexplained variance and the remarkably high number (69) of different tests that were used, which make more detailed conclusions problematic. This meta-analysis implies that future studies need to be of better quality, to have higher power, and to a higher degree use the same executive function tests.

Executive functions and their relationship with intellectual capacity and age in schoolchildren with intellectual disability

BACKGROUND

There is certain empirical evidence of, on the one hand, a positive correlation between executive functions (EFs) and intelligence in people with intellectual disability (ID) and, on the other hand, a slower rate of development of EFs in these people relative to people without ID. This evidence is not, however, unequivocal, and further studies are required.

METHODS

We analysed the relationship between development of EFs and both age and intellectual capacity, in a sample of 106 students with either ID or borderline intellectual functioning (BIF) at a special education centre [63 boys and 43 girls, 11-18 years old, mean total intelligence quotient (TIQ) of 59.6]. We applied nine instruments to evaluate both neuropsychological development (working memory, inhibitory control, cognitive flexibility, planning, processing speed and verbal fluency) and behavioural development [teachers' perceptions of the EFs of their students by Behavior Rating Inventory of Executive Function - Second Edition (BRIEF-2) School]. ID and BIF groups were statistically compared in terms of mean performance measures in EF tests. We looked at the correlation between EFs and age, and correlations between EFs and intelligence: TIQ, fluid intelligence [measured by the perceptual reasoning (PR) sub-index of Wechsler Intelligence Scale for Children-IV (WISC-IV)] and crystallised intelligence (measured by the verbal comprehension (VC) sub-index of WISC-IV). Regression models were built for variables with strong correlation.

RESULTS

In most of the tests used to evaluate EFs, the ID subgroup performed significantly worse than the subgroup with BIF. In general, teachers' thought that participants had 'medium-low' levels of EFs. TIQ, by WISC-IV scale, correlated significantly with scores in all tests for all EFs. The PR sub-index correlated significantly with 14 of the tests for EFs; 35% of the variation in PR can be explained by variation in performance in Picture Span (working memory) and Mazes (planning). The VC sub-index correlated weakly with seven of the EF tests. We found significant correlations in the ID group between age and scores in all tests of working memory and inhibitory control. Age - considering all participants - did not correlate with any of the variables of teachers' perception except for working memory, and this correlation was not strong.

CONCLUSIONS

The results of our study are consistent with descriptions of the typical population: (1) fluid intelligence is more related to EFs than crystallised intelligence is; and (2) working memory capacity is the EF most strongly related with general, fluid and crystallised forms of intelligence. The results suggest that as children and adolescents with ID/BIF get older, their capacities for working memory and inhibitory control increase; development of the other EFs studied was less evident. Teachers' perceptions of the EFs of children with ID or BIF were independent of intellectual capacity and age. More research is needed to delve further into the development of EFs in people with ID/BIF.

Study of the deficit in planning abilities of adults with Prader-Willi Syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a complex developmental genetic disorder associated with intellectual disability and deficits in executive functions which result in disorganisation and poor personal autonomy.

AIMS

This study aimed to determine impairments in planning skills of adults with PWS, in relation with their intellectual disabilities, as well as the influence of food compulsions on their performance.

METHODS AND PROCEDURES

A modified version of the Zoo Map from the Behavioural Assessment of the Dysexecutive Syndrome was used in three groups: a group of adults with PWS in comparison with two groups both matched on chronological age, one with typical development (TD) and one with intellectual disability (ID).

OUTCOMES AND RESULTS

Compared to TD adults, both adults with PWS and ID showed increased planning time and lower raw scores on the planning task. The execution time and the number of errors were higher in the PWS group compared to the comparison groups. All three groups performed worse in the non-food condition only for number of errors and raw score.

CONCLUSIONS AND IMPLICATIONS

Planning abilities were impaired in PWS adults. Results also showed that intellectual level plays a role in participants' performance. These findings are essential to understand the difficulties of people with PWS daily life.

Decoding Abilities in Adolescents with Intellectual Disabilities: The Contribution of Cognition, Language, and Home Literacy

Decoding abilities in individuals with intellectual disabilities (ID) are substantially lower than for typical readers. The underlying mechanisms of their poor reading remain uncertain. The aim of this study was to investigate the concurrent predictors of decoding ability in 136 adolescents with non-specific ID, and to evaluate the results in relation to previous findings on typical readers. The study included a broad range of cognitive and language measures as predictors of decoding ability. A LASSO regression analysis identified phonological awareness and rapid automatized naming (RAN) as the most important predictors. The predictors explained 57.73% of the variance in decoding abilities. These variables are similar to the ones found in earlier research on typically developing children, hence supporting our hypothesis of a delayed rather than a different reading profile. These results lend some support to the use of interventions and reading instructions, originally developed for typically developing children, for children and adolescents with non-specific ID.

Investigating Reading Comprehension in Adolescents with Intellectual Disabilities: Evaluating the Simple View of Reading

Reading comprehension difficulties are common in individuals with intellectual disabilities (ID), but the influences of underlying abilities related to reading comprehension in this group have rarely been investigated. One aim of this study was to investigate the Simple View of Reading as a theoretical framework to describe cognitive and linguistic abilities predicting individual differences in reading comprehension in adolescents with non-specific ID. A second aim was to investigate whether predictors of listening comprehension and reading comprehension suggest that individuals with ID have a delayed pattern of development (copying early grade variance in reading comprehension) or a different pattern of development involving a new or an unusual pattern of cognitive and linguistic predictors. A sample of 136 adolescents with non-specific ID was assessed on reading comprehension, decoding, linguistic, and cognitive measures. The hypotheses were evaluated using structural equation models. The results showed that the Simple View of Reading was not applicable in explaining reading comprehension in this group, however, the concurrent predictors of comprehension (vocabulary and phonological executive-loaded working memory) followed a delayed profile.

Susceptibility to Ingroup Influence in Adolescents With Intellectual Disability: A Minimal Group Experiment on Social Judgment Making

Adolescents with intellectual disability (ID) experience challenges and uncertainty when making judgments about other people's intentions. In an attempt to achieve certainty, they might exhibit judgment tendencies that differ from those of typically developing adolescents. This study investigated social judgment making in adolescents with ID (n = 34, M age = 14.89 years, SD = 1.41 years) compared with chronological age-matched adolescents without ID (n = 34, M age = 14.68 years, SD = 1.15 years) and mental age (MA)-matched children (n = 34, M age = 7.93 years, SD = 0.64 years). Participants used a computer-based task to judge the hostility of persons (fictitious characters). Adolescents with ID were found to make more polarizing judgments (i.e., either positive or negative, as opposed to moderate judgments) and were more likely to be guided by the opinions of a fictitious peer ingroup (minimal group) compared with adolescents without ID. No such differences were found between adolescents with ID and MA-matched children. The results are discussed in terms of scientific and practical implications.

Increased openness to external influences in adolescents with intellectual disability: Insights from an experimental study on social judgments

BACKGROUND

Making appropriate social judgments about one's peers helps avoid negative influences from peers, yet the cognitive and adaptive difficulties experienced by adolescents with an intellectual disability (ID) may create challenges in this regard.

PROCEDURE

This study used a computer-based task to investigate how adolescents with ID (n = 34, M = 14.89 years, SD = 1.38) and comparison groups of chronological age-matched adolescents without ID (n = 34, M = 14.68, SD = 1.16) and mental age-matched children (n = 34, M = 7.88, SD = .62) make social judgments of photos of adolescents, and the degree to which they are influenced by non-social and social cues in performing this task.

RESULTS

Analyses showed adolescents with ID made significantly more polarizing judgments and showed a positivity bias compared to adolescents without ID. This judgment pattern was similar to that of younger mental age-matched children. Adolescents with ID were also significantly more influenced by non-social cues and peer opinions than adolescents from the control group.

IMPLICATIONS

The results provide new perspectives for future research and support of adolescents with ID.

Duration judgments in children and adolescents with and without mild intellectual disability

BACKGROUND

While the ability to measure time correctly is crucial for adaptation to the external physical and social environment, to date, research on timing ability and its development in individuals with intellectual disability (ID) is unfortunately remarkably scarce.

AIMS

In the present study, we investigated the ability of individuals with mild ID to estimate durations and the development of this ability from 11 to 19 years, in comparison to typically developing (TD) individuals.

METHODS AND PROCEDURES

Participants with mild ID and TD participants matched on chronological age completed two temporal tasks: (1) a temporal bisection of auditory stimuli, in which they had to decide whether arbitrary stimulus duration was more similar to the short (200 ms) or the long (800 ms) standard previously learned, and (2) a temporal categorization of familiar actions, in which short, medium or long target durations had to be paired with one of three comparison action durations.

OUTCOMES AND RESULTS

Temporal performance was systematically impaired in participants with mild ID. Moreover, the temporal impairment increased with age in the bisection task but not in the categorization task.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that the ability to estimate durations develops at a slower pace in individuals with mild ID compared to TD individuals.

Investigation of the Clinical Utility of the BRIEF2 in Youth With and Without Intellectual Disability

OBJECTIVE

Executive function (EF) difficulties are commonly found in youth with intellectual disability (ID). Given mixed results from studies using performance-based EF measures, the EF profile has not been well characterized for this population. No published work has examined the clinical utility of the Behavior Rating Inventory of Executive Function, Second Edition (BRIEF2) in distinguishing EF in ID. We hypothesized that the BRIEF2 would show greater elevations in youth with ID compared to the Average IQ comparison group.

METHODS

Participants included a large sample of 504 youth (157 in ID group; aged 8-18 years) referred for (neuro)psychological evaluation (2015-2019) and identified as meeting criteria for either ID or Average IQ comparison group.

RESULTS

Significant elevations were found across BRIEF2 indices and scales. Only mild elevations were noted in selective cognitive regulation scales within the Average IQ group. Groups differed significantly across all EF dimensions, with greater differences observed in behavioral regulation (Self-Monitoring, Inhibition), Shift, and Working Memory. An elevated but less variable pattern of index scores was noted in ID, while the overall pattern of scaled scores appeared similar between groups.

CONCLUSIONS

The less variable and consistently elevated profile may suggest fewer EF dimensions in individuals with ID than the model proposed in the test manual. Similar profiles between groups may reflect differences in severity, rather than differences in constructs measured by the EF factors, per se. Additional examination is needed to confirm potential structural differences in EF for youth with ID as measured by BRIEF2, with a clinical implication for greater efficiency of EF assessment in this population.

Feasibility of a Tablet-Based Program for Training Everyday Planning in Adolescents With Intellectual Disabilities

Background

Individuals with intellectual disabilities (ID) show difficulties with everyday planning. A tablet-based training program for everyday planning may be a suitable intervention, but its feasibility must be evaluated. This study evaluated how behavior changes during training and if individuals with ID can use technology by themselves.

Method

Thirty-three adolescents with ID and 30 younger children with a typical development were recruited. The participants were instructed to train in school for a total of 300 minutes. After the intervention, the participants were matched on mental age (MA).

Results

Only 16% of the participants trained for all 300 minutes. Participants in the MA group trained for a longer time than the ID group. Both groups made fewer errors per task at the end compared to the beginning. Individuals with ID started off making less attempts per task and increased their activity during the training. This pattern was not seen in the comparison group.

Conclusions

Both groups used the program independently, without adult supervision. However, a large group of participants in the ID group had a low usage time. Thus, the program might not have been feasible for that subgroup. The ID group increased their activity during the training which might mirror a strategy development of how to use the program. The change in behavior in activity on task attempts can be interpreted such that individuals with ID need a longer time to get familiarized with the technology. Tablet-based training programs are feasible for individuals with ID, but it is necessary to follow up on usage time.

Parents act as intermediary users for their children when using assistive technology for cognition in everyday planning: Results from a parental survey

Assistive Technology for Cognition (ATC) is employed by children with and without disabilities. However, how the ATC is used in everyday life has not been studied. The current study investigated ATC-usage in everyday planning in three groups: 1) children qualifying for Swedish habilitation centers (ID/ASD), 2) children with disability not qualifying for habilitation service (ADHD), and 3) children with typical development (TD). A parental survey was conducted (n = 192) and answers were analyzed with statistical tests and inductive thematic text analysis. Results showed that all groups used ATC, most in the Habilitation group and least in the TD group. According to parents, ATC supported cognitive functions in all groups, but it became evident that the parents were responsible for planning by setting up the ATC, whilst the children merely executed the plans. This was linked to several limitations, for example the design was not appropriately adapted for these groups. The implications for the practitioners are 1) evaluate the users' cognitive abilities and choose an ATC suitable for that individual rather focusing on the diagnosis, and 2) follow up usage to see if it is the parent or the child that are using the ATC.

Executive Functions and Emotion Regulation in Attention-Deficit/Hyperactivity Disorder and Borderline Intellectual Disability

The main objective of this study is to investigate the multiple relations and to determine the differences between executive functions (EFs), emotion regulation, and behavioral and emotional problems in children with attention-deficit/hyperactivity disorder (ADHD), borderline intellectual disability (ID), and typical development (TD). The sample included 85 children aged 6 to 11 years, 42 with typical development (TD), 27 with ADHD, and 16 with borderline ID. The results emphasized a positive correlation between adaptive emotion regulation strategies and EFs, and no significant relations between the maladaptive emotion regulation strategies and EFs. In addition, the executive function of planning correlated negatively with anxiety, ADHD symptoms, and conduct problems. The performance of both clinical groups regarding EFs was significantly lower than that of the TD group, and they differed significantly from each other only on visual attention. The presence of oppositional-defiant and conduct problems was higher in both clinical groups than in the TD group, and more anxiety symptoms were reported in children with ADHD. This study supports the idea that emotion regulation, Efs, and clinical symptoms are interconnected. It also profiles the deficits in cognitive functioning and emotion regulation in two clinical groups, thus helping future intervention programs.

Cognitive abilities and life experience in everyday planning in adolescents with intellectual disabilities: Support for the difference model

BACKGROUND

The literature on planning ability in individuals with intellectual disability (ID) provides no clarity on whether their ability matches their mental age (MA) or not. Perhaps can planning experience explain the mixed results. The current study investigated to what extent cognitive abilities and life experience can explain everyday planning ability in individuals with ID and to what extent results from everyday planning tasks support the developmental or the difference model of ID.

METHOD

Planning tests, cognitive ability tasks and a self-rated life experience form were administered to 71 adolescents with ID and 62 children with a typical development matched on MA.

RESULTS

Adolescents with ID exhibited planning ability according to their MA. Regression analyses showed that the predictors of planning differed between the groups. The cognitive measures could predict planning in both groups, but life experience only contributed positively to planning in the MA group, whereas chronological age was negatively correlated with successful planning in the ID group.

CONCLUSIONS AND DISCUSSION

The results support the difference model of ID. When matched on MA, the individuals with ID will solve the planning task in a qualitatively different manner. Additionally, the participants with ID could not utilise their life experience when solving the planning task, contrary to the MA group. Practitioners should be aware that individuals with ID might need more everyday planning training throughout adolescence. To support adolescents with ID, practitioners may focus on supporting the individual's cognitive abilities rather than relying on their prior knowledge.

Suggestibility and false memories in relation to intellectual disability and autism spectrum disorder: a meta-analytic review

BACKGROUND

A systematic literature review was conducted to evaluate previous research that examined intellectual disability (ID) or autism spectrum disorder (ASD) in relation to memory distortions (i.e. suggestibility and false memories). There were two goals for the current study; the first goal was to identify significant trends in past literature that fulfilled previously established selection criteria. The second goal was to establish reliability and effect sizes for suggestibility and false memory for samples with diagnoses of ID or ASD.

METHODS AND PROCEDURES

Articles that were selected for inclusion in the current study were required to have a clinically diagnosed sample, as well as a non-clinical control group. Studies were also required to have a post-hoc power score higher than .30 to prevent the effects of underpowered studies and limit the potential for publication bias. Selected studies were also required to have provided pertinent information required to complete the analyses (e.g. means, standard deviations, p-values, or correlation coefficients). Any study that did not provide the required information was excluded.

RESULTS AND CONCLUSIONS

Two empirical Bayes omnibus analyses revealed a significant effect for participants diagnosed with ID (z = 6.10, p < .001), which supported the researchers' hypothesis. The results indicated increased susceptibility toward memory suggestibility and false memories when compared with the general population. However, the results of the analyses did not support the researchers' hypothesis regarding participants diagnosed with ASD. The analyses indicated that participants diagnosed with ASD displayed decreased suggestibility and were less likely to develop false memories (z = -2.37, p = 0.018).

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.

Risk Assessment of Adolescents with Intellectual Disabilities Who Exhibit Sexual Behavior Problems or Sexual Offending Behavior

Adolescents with intellectual disabilities are known to engage in various sexual behavior problems or sexual offending behaviors. This article provides a review of important aspects of risk assessment within the context of a broader, more comprehensive and holistic assessment of these individuals. Pertinent risk and sexual interest assessment tools are identified along with their strengths and limitations. Issues that are often unattended to are addressed, including consideration of the behavioral implications of the young person's diagnosis and level of cognitive functioning, need for sexual knowledge and sexual interest assessment, and issues related to making a mental health diagnosis. Recommendations for future research are also offered.

Social information processing skills link executive functions to aggression in adolescents with mild to borderline intellectual disability

Executive Functions (EFs) have been associated with aggression in children and adolescents. EFs as higher-order cognitive abilities are assumed to affect cognitive functions such as Social Information Processing (SIP). We explored SIP skills as a mediating mechanism linking EFs to aggression in adolescents with mild to borderline intellectual disability (MBID with IQ from 50-84), a high risk group for aggressive behaviors and EF impairments. A total of 153 adolescents (M_age = 15.24, SD = 1.35; 54% male) with MBID participated. Focused attention, behavioral inhibition, and working memory were tested with multiple neurocognitive tasks to define latent EF constructs. Participants responded to a video-based SIP task. A latent construct for aggression was defined by caretaker, teacher, and adolescent self-reports of aggression (Child Behavior Check List, Teacher Report Form, and Youth Self Report). Structural equation modeling was performed to test mediation. Results were consistent with mediation of the relation between focused attention and aggression by SIP, namely via hostile interpretations and self-efficacy for aggression. Behavioral inhibition was linked to aggression, but this relation was not mediated by SIP. The relation between working memory and aggression was mediated by SIP, namely via hostile interpretations, aggressive response generation and via self-efficacy for aggressive responses. Bearing the cross-sectional design in mind, support was found for SIP skills as a mechanism linking EFs, in particular focused attention and working memory, to aggression, providing a viable explanation for the high vulnerability of adolescents with MBID for aggression.

Critical reappraisal of mechanistic links of copy number variants to dimensional constructs of neuropsychiatric disorders in mouse models

Copy number variants are deletions and duplications of a few thousand to million base pairs and are associated with extraordinarily high levels of autism spectrum disorder, schizophrenia, intellectual disability, or attention-deficit hyperactivity disorder. The unprecedented levels of robust and reproducible penetrance of copy number variants make them one of the most promising and reliable entry points to delve into the mechanistic bases of many mental disorders. However, the precise mechanistic bases of these associations still remain elusive in humans due to the many genes encoded in each copy number variant and the diverse associated phenotypic features. Genetically engineered mice have provided a technical means to ascertain precise genetic mechanisms of association between copy number variants and dimensional aspects of mental illnesses. Molecular, cellular, and neuronal phenotypes can be detected as potential mechanistic substrates for various behavioral constructs of mental illnesses. However, mouse models come with many technical pitfalls. Genetic background is not well controlled in many mouse models, leading to rather obvious interpretative issues. Dose alterations of many copy number variants and single genes within copy number variants result in some molecular, cellular, and neuronal phenotypes without a behavioral phenotype or with a behavioral phenotype opposite to what is seen in humans. In this review, I discuss technical and interpretative pitfalls of mouse models of copy number variants and highlight well-controlled studies to suggest potential neuronal mechanisms of dimensional aspects of mental illnesses. Mouse models of copy number variants represent toeholds to achieve a better understanding of the mechanistic bases of dimensions of neuropsychiatric disorders and thus for development of mechanism-based therapeutic options in humans.

Basal ganglia involvement in ARX patients: The reason for ARX patients very specific grasping?

The ARX (Aristaless Related homeoboX) gene was identified in 2002 as responsible for XLAG syndrome, a lissencephaly characterized by an almost complete absence of cortical GABAergic interneurons, and for milder forms of X-linked Intellectual Disability (ID) without apparent brain abnormalities. The most frequent mutation found in the ARX gene, a duplication of 24 base pairs (c.429_452dup24) in exon 2, results in a recognizable syndrome in which patients present ID without primary motor impairment, but with a very specific upper limb distal motor apraxia associated with a pathognomonic hand-grip, described as developmental Limb Kinetic Apraxia (LKA).

In this study, we first present ARX expression during human fetal brain development showing that it is strongly expressed in GABAergic neuronal progenitors during the second and third trimester of pregnancy. We show that although ARX expression strongly decreases towards the end of gestation, it is still present after birth in some neurons of the basal ganglia, thalamus and cerebral cortex, suggesting that ARX also plays a role in more mature neuron functioning. Then, using morphometric brain MRI in 13 ARX patients carrying c.429_452dup24 mutation and in 13 sex- and age-matched healthy controls, we show that ARX patients have a significantly decreased volume of several brain structures including the striatum (and more specifically the caudate nucleus), hippocampus and thalamus as well as decreased precentral gyrus cortical thickness. We observe a significant correlation between caudate nucleus volume reduction and motor impairment severity quantified by kinematic parameter of precision grip.

As basal ganglia are known to regulate sensorimotor processing and are involved in the control of precision gripping, the combined decrease in cortical thickness of primary motor cortex and basal ganglia volume in ARX dup24 patients is very likely the anatomical substrate of this developmental form of LKA.

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c.429_452dup24 in ARX is responsible for ID with Limb Kinetic Apraxia.

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During human brain development, ARX is expressed in GABAergic neuronal progenitors.

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ARX patients have a significantly decreased caudate nucleus volume by MRI.

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This caudate nucleus volume reduction is correlated with motor impairment severity.

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These anatomic findings may explain this developmental form of Limb Kinetic Apraxia.

Copy number elevation of 22q11.2 genes arrests the developmental maturation of working memory capacity and adult hippocampal neurogenesis

Working memory capacity, a critical component of executive function, expands developmentally from childhood through adulthood. Anomalies in this developmental process are seen in individuals with autism spectrum disorder (ASD), schizophrenia and intellectual disabilities (ID), implicating this atypical process in the trajectory of developmental neuropsychiatric disorders. However, the cellular and neuronal substrates underlying this process are not understood. Duplication and triplication of copy number variants of 22q11.2 are consistently and robustly associated with cognitive deficits of ASD and ID in humans, and overexpression of small 22q11.2 segments recapitulates dimensional aspects of developmental neuropsychiatric disorders in mice. We capitalized on these two lines of evidence to delve into the cellular substrates for this atypical development of working memory. Using a region- and cell-type-selective gene expression approach, we demonstrated that copy number elevations of catechol-O-methyl-transferase (COMT) or Tbx1, two genes encoded in the two small 22q11.2 segments, in adult neural stem/progenitor cells in the hippocampus prevents the developmental maturation of working memory capacity in mice. Moreover, copy number elevations of COMT or Tbx1 reduced the proliferation of adult neural stem/progenitor cells in a cell-autonomous manner in vitro and migration of their progenies in the hippocampus granular layer in vivo. Our data provide evidence for the novel hypothesis that copy number elevations of these 22q11.2 genes alter the developmental trajectory of working memory capacity via suboptimal adult neurogenesis in the hippocampus.

Everyday executive function in focal onset pediatric epilepsy on the parent-report BRIEF2

Executive function (EF) difficulties are a core neuropsychological feature of pediatric epilepsy, and parent-report measures of EF concerns are an important complement to task-based EF measures. The Behavior Rating Inventory of Executive Function (BRIEF) has shown sensitivity to parent-reported EF concerns in epilepsy and other pediatric populations. We compared profiles of parent-reported EF concerns using the BRIEF and its revision, the BRIEF2, in 117 pediatric patients with focal onset epilepsy to examine the clinical utility of the revised scale. We then compared BRIEF2 profiles between patients and age- and gender-matched healthy controls. Among patients, profiles on the BRIEF did not globally differ from the BRIEF2, and agreement was very good across scales. Patients and controls differed significantly on the BRIEF2, with patients showing higher EF difficulties reported by parents across most scales. High rates of clinical elevation among patients emerged on the Task Monitor, Plan/Organize, Working Memory, and Shift scales. Younger age of epilepsy onset, chronic epilepsy, and right hemisphere seizure focus were associated with higher parent-reported EF concerns. Findings suggest that the BRIEF2 demonstrates similar performance to the BRIEF among pediatric patients with focal onset epilepsy who are most at risk in the areas of task monitoring, working memory, planning and organization, and flexibility. These findings are informative when comparing literature across versions and provide additional insight into the nature of parent-reported EF difficulties among children with focal onset epilepsy.

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.

Memory and linguistic/executive functions of children with borderline intellectual functioning

Children with Borderline Intellectual Functioning (BIF) have received a minimal amount of research attention and have been studied in conjunction with Intellectual and Developmental Disabilities. The present study intends to broaden the knowledge of BIF, by analyzing domains such as verbal memory and visual memory, as well as tasks that rely simultaneously on memory, executive functions, and language. A cross-sectional, comparison study was carried out between a group of 40 children with BIF (mean age = 10.03; 24 male and 16 female), and a control group of 40 normal children of the same age, gender, and socioeconomic level as the BIF group. The WISC-III Full Scale IQs of the BIF group ranged from 71 to 84. The following instruments were used: Word List, Narrative Memory, Rey Complex Figure, Face Memory, Rapid Naming (both RAN and RAS tests), and Verbal Fluency. The results showed deficits in children with BIF in verbal short-term memory, rapid naming, phonemic verbal fluency, and visual short-term memory, specifically in a visual recognition task, when compared with the control group. Long-term verbal memory was impaired only in older children with BIF and long-term visual memory showed no deficit. Verbal short-term memory stands out as a limitation and visual long-term memory as a strength. Correlations between the WISC-III and neuropsychological tests scores were predominantly low. The study expands the neuropsychological characterization of children with BIF and the implications of the deficits and strengths are stressed.

Problem-solving styles in autism spectrum disorder and the development of higher cognitive functions

The Vygotsky Blocks Test assesses problem-solving styles within a theoretical framework for the development of higher mental processes devised by Vygotsky. Because both the theory and the associated test situate cognitive development within the child's social and linguistic context, they address conceptual issues around the developmental relation between language and thought that are pertinent to development in autism. Our aim was to document the performance of adults with autism spectrum disorder on the Vygotsky Blocks Test, and our results showed that they made more errors than the typically developing participants and that these errors correlated with performance IQ. The autism spectrum disorder group also required more cues than the typically developing group to discern the conceptual structure of the blocks, a pattern that correlated with Autism Diagnostic Observational Schedule-Communication and Imagination/Creativity sub-scales. When asked to categorize the blocks in new ways, the autism spectrum disorder participants developed fewer principles on which to base new categorizations, which in contrast to the typically developing group correlated with verbal IQ and with the Imagination/Creativity sub-scale of the ADOS. These results are in line with a number of existing findings in the autism spectrum disorder literature and confirm that conceptualization in autism spectrum disorder seems to rely more on non-verbal and less on imaginative processes than in typically developing individuals. The findings represent first steps to the possibility of outlining a testable account of psychological development in autism spectrum disorder that integrates verbal, non-verbal and social factors into the transition from elementary to higher level processes.

Skill-related physical fitness versus aerobic fitness as a predictor of executive functioning in children with intellectual disabilities or borderline intellectual functioning

Children with intellectual disabilities (ID) or borderline intellectual disabilities (BIF) often demonstrate impairments in executive functioning (EF). Studies in typically developing children show that aerobic fitness (AF) is positively related with EF. Skill-related physical fitness (SF) might, however, be a stronger predictor of EF than AF, as cognitive challenges are inherent in application of these skills. In this study, AF and SF were examined simultaneously in relationship with domains of EF in children with ID or BIF. Seventy-three children (age range 8-11; 51 boys) with ID (IQ range 56-79) or BIF (IQ range 71-79) were measured annually over a period of 4 years on AF (20-m endurance shuttle run test) and SF (plate tapping and 10×5m run). EF was measured with the Stroop Color-Word test (inhibition), Trailmaking and Fluency test (cognitive flexibility), Self-ordered pointing task (working memory) and the Tower of London (planning). Multilevel models showed that SF was significantly associated with inhibition and both measures of cognitive flexibility, but in the same models no significant associations between AF and EF were found. In addition, age was significantly related to working memory and cognitive flexibility, favouring the older children. In children with ID or BIF, SF is of greater importance than AF in relationship with core domains of EF.

Verlauf exekutiver Funktionen bei Vorschulkindern mit Entwicklungsauffälligkeiten

Zusammenfassung. Verschiedene Entwicklungsauffälligkeiten wie ADHS-Symptome, spezifische Sprachentwicklungsschwierigkeiten (SSES) oder auch niedrige Intelligenz (NI) gehen mit Schwierigkeiten in den exekutiven Funktionen und der Selbstregulation einher. In der vorliegenden längsschnittlichen Studie absolvierten 22 Kinder mit ADHS-Symptomen, 24 Kinder mit SSES und 24 Kinder mit NI sowie 35 unauffällige Kontrollkinder im Alter von 5 und 6 Jahren Aufgaben zu allen drei Komponenten exekutiver Funktionen nach dem Modell von Miyake et al. (2000) – Updating, Shifting, Inhibition. Die Ergebnisse belegen sowohl überlappende als auch spezifische Schwierigkeiten für die einzelnen Störungsbilder: Kinder mit ADHS-Symptomen zeigten Defizite in Shifting und Inhibition, Kinder mit SSES ebenfalls beim Shifting, Kinder mit NI insbesondere beim Updating. Im letzten Kindergartenjahr konnten Kinder mit NI und SSES ihre Leistungen in der Inhibition an das Niveau der Kontrollgruppe angleichen, Kinder mit ADHS-Symptomen blieben jedoch hinter den anderen Gruppen zurück. Die Befunde können Anlass sein, spezifische Interventionsmaßnahmen zu entwickeln.

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.

The impact of behavioural executive functioning and intelligence on math abilities in children with intellectual disabilities

BACKGROUND

Little is known about the role of behavioural executive functioning (EF) skills and level of intelligence (IQ) on math abilities in children with mild to borderline intellectual disabilities.

METHOD

Teachers of 63 children attending a school for special education (age: 10 to 13 years; IQ: 50 to 85) filled out a Behaviour Rating Inventory for Executive Function for each student. Furthermore, students took a standardised national composite math test and a specific math test on measurement and time problems. Information on level of intelligence was gathered through school records. Multiple regression analyses were performed to test direct, moderating and mediating effects of EF and IQ on math performance.

RESULTS

Behavioural problems with working memory and flexibility had a direct negative effect on math outcome, while concurrently, level of intelligence had a positive effect. The effect of IQ on math skills was moderated by problems with inhibition: in children with a clinical level of inhibition problems, there was no effect of level of intelligence on math performance.

CONCLUSIONS

Findings suggest that in students with mild to borderline intellectual disabilities and math difficulties, it is important to address their strengths and weaknesses with respect to EF and adjust instruction and remedial intervention accordingly.

The Role of Executive Functions in Social Cognition among Children with Down Syndrome: Relationship Patterns

Many studies show a link between social cognition, a set of cognitive and emotional abilities applied to social situations, and executive functions in typical developing children. Children with Down syndrome (DS) show deficits both in social cognition and in some subcomponents of executive functions. However this link has barely been studied in this population. The aim of this study is to investigate the links between social cognition and executive functions among children with DS. We administered a battery of social cognition and executive function tasks (six theory of mind tasks, a test of emotion comprehension, and three executive function tasks) to a group of 30 participants with DS between 4 and 12 years of age. The same tasks were administered to a chronological-age control group and to a control group with the same linguistic development level. Results showed that apart from deficits in social cognition and executive function abilities, children with DS displayed a slight improvement with increasing chronological age and language development in those abilities. Correlational analysis suggested that working memory was the only component that remained constant in the relation patterns of the three groups of participants, being the relation patterns similar among participants with DS and the language development control group. A multiple linear regression showed that working memory explained above 50% of the variability of social cognition in DS participants and in language development control group, whereas in the chronological-age control group this component only explained 31% of the variability. These findings, and specifically the link between working memory and social cognition, are discussed on the basis of their theoretical and practical implications for children with DS. We discuss the possibility to use a working memory training to improve social cognition in this population.