Differences in the intellectual profile of children with intellectual vs. learning disability

Etiology of Borderline Intellectual Functioning

Borderline intellectual functioning (BIF), characterized by intelligence quotient scores between 70 and 85, can lead to challenges in daily life. This review explored the multifaceted nature of BIF by examining the interplay between genetic predisposition, prenatal/perinatal factors, environmental influences, and underlying medical conditions.

Questioning cognitive heterogeneity and intellectual functioning in fetal alcohol spectrum disorders from the Wechsler Intelligence Scale for Children

Introduction: Fetal Alcohol Spectrum Disorders (FASD) are characterized by a variety of multiple cognitive and behavioral impairments, with intellectual, attentional, and executive impairments being the most commonly reported. In populations with multiple neurodevelopmental disorders, the Full Scale Intelligence Quotient (FSIQ) may not be a proper measure of intellectual abilities, rarely interpreted in FASD clinical practice because the heterogeneity of the cognitive profile is deemed too strong. We propose a quantitative characterization of this heterogeneity, of the strengths and weaknesses profile, and a differential analysis between global cognitive (FSIQ) and elementary reasoning abilities in a large retrospective monocentric FASD sample. Methods: Using clinical and cognitive data (Wechsler Intelligence Scale for Children) from 107 children with FASD, we characterized subject heterogeneity (variance and scatter of scaled/composite scores), searched for strengths and weaknesses, and specified intellectual functioning in terms of FSIQ and elementary reasoning (General Abilities Index, Highest Reasoning Scaled Score), in comparison with standardization norms and a Monte-Carlo-simulated sample from normalization data. Results: Performance of children with FASD was lower on all subtests, with a significant weakness in working memory and processing speed. We found no increase in the variance and scatter of the scores, but a discordance between the assessment of global cognitive functioning (28% borderline, 23% deficient) and that of global and elementary reasoning abilities (23-9% borderline, 15-14% deficient). Conclusion: Our results question the notion of WISC profile heterogeneity in FASD and point to working memory and processing speed over-impairment, with global repercussions but most often preserved elementary reasoning abilities.

The Intellectual Profile of Adults with Specific Learning Disabilities

Despite growing research on adults with specific learning disabilities (SLDs), evidence concerning their intellectual profile remains scarce. The present study examined the results of the administration of the Wechsler Adult Intelligence Scale-Fourth Edition to 301 adults diagnosed with SLDs and compared them to the results obtained from previous studies with a large sample of children with SLDs. The results showed that: (1) as observed among children, adults with SLDs also presented higher scores in the subtests implying reasoning (associated with the General Ability Index, GAI) and lower scores in the subtests involving working memory and processing speed; (2) the discrepancy between full-scale IQ and the GAI had a good predictive value in discriminating adults with and without SLDs; (3) the four-factor hierarchical structure of intelligence proposed for the general adult population held for adults with SLDs as well, even though there were substantial differences in the loadings and a five-factor structure could be more appropriate; (4) similarities as well as strong differences were present between adults and children with SLDs. In adults, scores on subtests were generally lower, particularly in working memory and processing speed. However, in some cases, scores were equal or even higher (as in the "Similarity" subtest) among adults, meaning that the discrepancy between the full scale and the GAI was accentuated.

Cognitive Profile Discrepancies among Typical University Students and Those with Dyslexia and Mixed-Type Learning Disorder

BACKGROUND

Previous studies have identified areas of cognitive weakness in children diagnosed with Specific Learning Disorder (SLD), in the areas of working memory and processing speed in particular. In adulthood, this literature is still scant, and no studies have compared the cognitive profile of university students with dyslexia (DD) with that of students with Mixed-type SLD.

METHOD

Thus, in this study, the WAIS-IV was used to examine the cognitive functioning of three groups of university students: students with DD, with Mixed-type SLD, and typical students. Statistical analyses were performed to examine differences in WAIS-IV FSIQ, main, and additional indexes and subtests.

RESULTS

The results showed strengths in perceptual reasoning and good verbal comprehension abilities in both the DD and Mixed-type SLD group, with weaknesses in working memory and processing speed, leading to a pattern of a better General Ability Index (GAI) than Cognitive Proficiency Index (CPI) in both clinical groups. Thus, discrepancies between GAI and CPI, well documented in children with SLD, still manifest in adulthood in university students. Our findings also revealed worse cognitive performance in university students with mixed learning disorder relative to students with only a reading deficit.

CONCLUSIONS

The cognitive features and distinctive subtest profiles that emerged should guide the assessment and the definitions of intervention programs, special educational needs, and strategies of compensation.

Low discriminative power of WISC cognitive profile in developmental dyscalculia

BACKGROUND

The role of domain-general cognitive abilities in the etiology of Developmental Dyscalculia (DD) is a hotly debated issue.

AIMS

In the present study, we tested whether WISC-IV cognitive profiles can be useful to single out DD.

METHODS AND PROCEDURES

Using a stringent 2-SD cutoff in a standardized numeracy battery, we identified children with DD (N = 43) within a clinical sample referred for assessment of learning disability and compared them in terms of WISC cognitive indexes to the remaining children without DD (N = 100) employing cross-validated logistic regression.

OUTCOMES AND RESULTS

Both groups showed higher Verbal Comprehension and Perceptual Reasoning than Working Memory and Processing Speed, and DD scores were generally lower. Predictive accuracy of WISC indexes in identifying DD individuals was low (AUC = 0.67) and it dropped to chance level in discriminating DD from selected controls (N = 43) with average math performance but matched on global IQ. The inclusion of a visuospatial memory score as an additional predictor did not improve classification accuracy.

CONCLUSIONS AND IMPLICATIONS

These results demonstrate that cognitive profiles do not reliably discriminate DD from non-DD children, thereby weakening the appeal of domain-general accounts.

Perceiving Oneself to Be Integrated into the Peer Group: A Protective Factor against Victimization in Children with Learning Disabilities

Bullying is still a widespread social problem that needs serious attention. To date, research on this topic has shown that understanding the phenomenon requires a psychosocial perspective. The primary goal of the study is to identify the factors that contribute to the victimization of students with learning disabilities. The hypothesis is that the victimization experiences of this group of students can be explained by some socio-relational dynamics. Using a mediation model, this study demonstrates that perceived social integration completely mediates the association between the presence of learning disabilities and victimization experiences. This implies that students with learning disabilities are primarily victimized when they are not socially integrated into their class group. The implications for diagnosis and treatment are discussed.

The structure, profile, and diagnostic significance of intelligence in children with ADHD are impressively similar to those of children with a specific learning disorder

This study examines the structure, profile, and diagnostic significance of intelligence in a group of 948 children diagnosed with attention deficit/hyperactivity disorder (ADHD) assessed with the WISC-IV and compared with children with specific learning disorders (SLDs) and with typically developing children. Based on four indexes, the WISC-IV configuration found in TD resulted applicable to ADHD, but with generally lower loadings on g. The Perceptual Reasoning and Verbal Comprehension indexes not only had higher loadings compared to the other two indexes but also represented the relative strengths of children with ADHD, as previously observed for children with SLD. In fact, the WISC pattern could be successfully used for discriminating between ADHD and TD, but not between ADHD and SLD. The latter result was not due to a co-occurrence of a learning disorder because the presence or absence of an associated diagnosis of SLD negligibly affected the pattern observed in ADHD. We concluded that the characteristics of intelligence in children with ADHD can be relevant for assessing this disorder, and that ADHD and SLDs share largely similar underlying cognitive features.

WISC-IV and Rey Auditory Verbal Learning Test Indicators of Specific Learning Disorder and Discrepant Academic Achievement

Though several studies have been undertaken to explore the correlates of academic achievement, there is a dearth of studies relating to the cognitive profiles of children who show marked discrepancies between their cognitive potential and actual academic achievement. The present study was undertaken in this context. The study was conducted on a sample of 308 students in the age range of 12–16 years, drawn from different schools in Kerala, India. The participants belonged to four groups, that is, Underachievers, Normal achievers, Overachievers, and those with Specific Learning Disorders (SLD). WISC-IV India and Rey Auditory Verbal Learning Test (RAVLT) were used for assessing cognitive functions. Results indicated that the SLD group could be discriminated from the other three groups in terms of Digit span, Letter-Number sequencing, Working Memory Index, and Processing Speed Index. Further, a retention score obtained from RAVLT could discriminate between the SLD and UA groups. Discriminant analysis of the variables resulted in the extraction of two significant functions composed of three variables of WISC and two variables of RAVLT. The results indicated that the different groups of scholastically backward children, though similar in their overall IQ, had distinct and characteristic cognitive profiles.

Students with dyslexia between school and university: Post-diploma choices and the reasons that determine them. An Italian study

Although the number of students with dyslexia enrolled in Italian universities is constantly growing, their presence remains relatively limited. The aim of this study was therefore to investigate the choices made by students with dyslexia in relation to university studies, and the underlying reasons for their choices. This study also compares these choices for students with and without dyslexia. In all, 440 high school students and their families agreed to take part in this project. Socio-demographic data was collected for the 47 students with dyslexia and 47 class-matched students without dyslexia, along with information on their current schools and their future educational plans. A specially developed questionnaire was used for the students, in combination with structured interviews with their families. The results show significant differences between these groups regarding both choices for university studies and the underlying motivations for these choices. Furthermore, certain psychological and emotional factors are implicated here in the decisions of the students with dyslexia regarding both university studies and their underlying reasons. Future research is needed to further investigate these factors in the educational choices of students with dyslexia.

Reading and spelling disorders in a school-based population screening in Sicily (Italy)

This research was carried out according to the Italian Consensus Conference on Specific Learning Disability guidelines for screening initiatives. It describes a three-year screening project involving 2.469 students, aged 8-15 years, from various classes of primary, lower and upper secondary schools of Sicily. Students were assessed for reading and spelling skills. Overall, 4.9% met the risk criteria for suspected reading disorder, 6.1% for spelling disorder, while 8.5% for both conditions. Results showed that out of 932 pupils in the primary school, 4.6% met the risk criteria for reading disorder and 6.5% for spelling disorder; out of 855 pupils of the lower secondary school, 5.3% for reading disorder and 5.5% for spelling disorder; out of 652 pupils of the upper secondary school, 4.9% for reading disorder and 6.1% for spelling disorder. No significant difference in the prevalence of students at risk of reading disorder or spelling disorder, within the three grade-levels over 3 years, was found. At project conclusion further clinical investigation to verify the screening results on student sub-sample (57%) was carried out. The percentage of students with SLD was equal to 3.15%, in the primary school, 3.76% in the lower secondary school and 2.51%, in the upper secondary school.

Cognitive differences between adults with traumatic brain injury and specific learning disorder

Background: Impaired working memory, attention, and processing speed are common in individuals with traumatic brain injury (TBI) and specific learning disorder (SLD). Yet, there is a paucity of research that has examined cognitive differences between these groups.Objective: The current study examined potential group differences between individuals with TBI and SLD on performance-based tests of working memory, attention, and processing speed. Subsequently, the study examined whether just processing speed tests could discriminate persons with TBI versus SLD.Method: The authors analyzed archival data to assess differences between 39 adult participants with moderate-severe TBI versus 57 adult participants with SLD on the Trail Making Test Part A, Trail Making Test Part B, Digit Span test, and Symbol Search test.Results: 95% confidence intervals revealed that participants with TBI performed significantly worse on the Trail Making Test Part A and Symbol Search test. Logistic regression analysis procedures revealed that Trail Making Test Part A was the most sensitive discriminator.Conclusion: Diagnosis of moderate-severe TBI compared to SLD can be determined by poor performance on measures of visual scanning and processing speed. These findings may be used for diagnostic interpretation and treatment planning by clinicians.

Long-term cognitive, executive, and behavioral outcomes of moderate and late preterm at school age

BACKGROUND

There is increasing concern that moderate preterm (32-33 weeks' gestation) and late preterm (34-36 weeks' gestation) birth may be associated with minor neurodevelopmental problems affecting poor school performance.

PURPOSE

We explored the cognitive function, cognitive visual function, executive function, and behavioral problems at school age in moderate to late preterm infants.

METHODS

Children aged 7-10 years who were born at 32+0 to 36+6 weeks of gestation and admitted to the neonatal intensive care unit from August 2006 to July 2011 at the National Health Insurance Service Ilsan Hospital were included. We excluded children with severe neurologic impairments, congenital malformations, or chromosomal abnormalities. Neuropsychological assessments consisted of 5 neuropsychological tests and 3 questionnaires.

RESULTS

A total of 37 children (mean age, 9.1±1.2 years) participated. The mean gestational age at birth was 34.6±7.5 weeks, while the mean birth weight was 2,229.2±472.8 g. The mean full-scale intelligence quotient was 92.89±11.90; 24.3% scored between 70 and 85 (borderline intelligence functioning). An abnormal score was noted for at least one of the variables on the attention deficit hyperactivity disorder diagnostic system for 65% of the children. Scores below borderline function for executive quotient and memory quotient were 32.4% and 24.3%, respectively. Borderline or clinically relevant internalizing problems were noted in 13.5% on the Child Behavior Check List. There were no significant associations between perinatal factors or socioeconomic status and cognitive, visual perception, executive function, or behavior outcomes.

CONCLUSION

Moderate to late preterm infants are at risk of developing borderline intelligence functioning and attention problems at early school age. Cognitive and executive functions that are important for academic performance must be carefully monitored and continuously followed up in moderate to late preterm infants.

Intellectual profile in school-aged children with borderline intellectual functioning

BACKGROUND

Little is currently known about borderline intellectual functioning (BIF), a condition characterized by an intelligence quotient between one and two standard deviations below the average, that affects about 14% of the population.

AIMS

The present study aimed to analyze the intellectual profile of school-aged children with BIF.

METHOD AND PROCEDURE

The WISC-IV was administered to 204 children with BIF attending Italian primary and lower secondary school, and their profile was compared with that of a control group of typically developing (TD) children.

RESULTS

The WISC-IV profile of the children with BIF differed from that of the TD children, and the former's performance was worse than the latter's in all the measures considered. The children with BIF also showed significant differences between the four main factor indices, scoring lowest for working memory, while the TD control group's profile was flat (as expected on the grounds of standardization criteria). No differences were found between the profiles of children with versus without a comorbid neurodevelopmental disorder.

DISCUSSION

Our results support the hypothesis that individuals with BIF have a characteristic profile with specific weaknesses.

Processing Speed is Impaired in Adults with Autism Spectrum Disorder, and Relates to Social Communication Abilities

Autism spectrum disorder (ASD) is characterized by a variety of social and non-social behavioral deficits. One potential mechanism that could unify this diverse profile of behaviors is slower processing speed. Seventy-six high-functioning adults with ASD were compared to 64 matched controls on standardized measures of processing speed. Participants with ASD were significantly slower on all measures, and on the composite score from the three tests (d's > .65). ASD participants with slower processing speeds scored higher on the ADOS Communication and Reciprocal Social Interaction scale (r = .34). These findings provide evidence of slower processing speeds in adults with ASD, and that this may be contributing to impairments in social communication skills. Interventions that improve processing speed might improve social communication abilities in ASD.

Lexical decision performance using the divided visual field technique following training in adults with intellectual disabilities with and without Down syndrome

Studies of brain lateralization in individuals with non-specific intellectual disability and Down syndrome suggest atypical brain lateralization to speech perception. According to the biological dissociation model, the right hemisphere (RH) mediates speech perception and the left hemisphere (LH) mediates motor control in Down syndrome. The current study aimed to test, for the first time, brain lateralization in both non-specific intellectual disability and Down syndrome, compared to individuals with typical development. Furthermore, bilateral word presentation was utilized to assess interhemispheric communication. Twenty adults with non-specific intellectual disability, 14 adults with Down syndrome, and 30 adults with typical development participated in the study. Participants in the non-specific intellectual disability and Down syndrome groups were trained to perform the task prior to the experiment. The results showed that whereas hemispheric lateralization did not differ between individuals with non-specific intellectual disability and typical development, individuals with DS showed reduced brain lateralization in comparison to adults with typical development. All three groups showed no significant difference between words presented to the LH and bilaterally. Our results also show that individuals with intellectual disabilities can benefit from training programmes and that they may perform equally as fast as their typically developing peers.

The intellectual profile of children with autism spectrum disorders may be underestimated: A comparison between two different batteries in an Italian sample

Intelligence measures are typically used in the assessment of children with autism spectrum disorders (ASD), but there is a paucity of research on the implications of such testing. In the present study, we examined children with ASD using two of the most largely adopted instruments, i.e., the WISC-IV, arguably the most utilized scale in the world; and the Leiter-3, a nonverbal scale that also excludes, from the IQ calculation, working memory and processing speed, which are points of weakness in ASD. Results showed that IQ and indices of these two batteries are strongly correlated. However, the WISC-IV IQ might underestimates the potential of children with ASD, particularly in children with a low functioning profile. These hold true for both the full scale IQ and three out of four indices of the WISC-IV, with remarkable implications for both assessment and treatment of these children. Practitioners working with children with ASD should be aware that the battery that they are using might severely affect the estimation of these children's potential.

Specific conditions for a selective deficit in memory for order in children with dyslexia

Short-term memory (STM) models distinguish between item and order memorization. The present study aims to explore how item and order STM are affected by the nature of the stimuli, the sequential versus simultaneous mode of presentation, the visual versus auditory presentation modality, the possibility of verbal recoding. A total of 20 children with dyslexia were matched one-by-one with 20 typically reading children on sex, age (8-14 years), and grade. Computerized STM tasks were administered while manipulating type (item vs. order), stimuli (letters vs. colors), sequentiality, input and output modality, as well as the presence/absence of articulatory suppression and distractors. General Linear Model analyses were conducted on accuracy scores for item and order STM. Both item and order recall scores were lower for children with dyslexia. Although order STM in the visual input condition turned out to be more impaired than item STM in the dyslexic group, both item and order memory impairments become evident when verbal recoding is prevented through articulatory suppression. Moreover, dyslexic children, unlike typical readers, were not facilitated by the linguistic nature of the stimuli to be remembered. The present findings suggest that the often-reported selective impairment of serial memory in dyslexia is restricted to stimuli that are verbal in nature or can be verbally recoded, whereas both item and order memory impairments become evident when verbal recoding is prevented through articulatory suppression. The presence of distractors is particularly detrimental to STM in the dyslexic group. The sensitivity to distractors, suppression, and stimuli in STM is predictive of reading performance.

Short Forms of Wechsler Scales Assessing the Intellectually Gifted Children Using Simulation Data

Intellectual giftedness is usually defined in terms of having a very high Intellectual Quotient (IQ). The intellectual capacity is assessed by a standardized test such as the Wechsler Intelligence Scale for Children (WISC). However, the identification of intellectually gifted children (IGC) often remains time-consuming. A short-form WISC can be used as a screening instrument. The practitioners and researchers in this field can then make a more in-depth evaluation of the IGC's cognitive and socioemotional characteristics if needed. The aim of our study is thus to determine the best short tests, in terms of their psychometric qualities, for the identification of IGC. The current study is composed of three-step analyses. Firstly, we created nine IQs short forms (IQ_SF) with 2-subtests, and nine IQ_SF with 4-subtests from the WISC-IV (Wechsler, 2005). Secondly, we estimated psychometric parameters (i.e., reliability and validity) from empirical and simulated dataset with WISC-IV. The difference in the estimation of psychometric qualities of each IQ_SF from the simulated data is very close to those derived from empirical data. We thus selected the three best IQ_SF based on these psychometrics parameters estimated from simulated datasets. For each selected short form of the WISC-IV, we estimated the screening quality in our sample of IGC. Thirdly, we created IQ_SF with 2- and 4-subtests from the WISC-V (Wechsler, 2016) with simulated dataset. We then highlighted the three best short forms of WISC-V based on the estimated psychometric parameters. The results are interpreted in terms of validity, reliability and screening quality of IGC. In spite of the important changes in the WISC-V, our findings show that the 2-subtest form, Similitaries + Matrix Reasoning, and 4-subtest form, Similitaries + Vocabulary + Matrix Reasoning + Block Design, are the most efficient to identify the IGC at the two recent versions of Wechsler scales. Finally, we discuss the advantages and drawbacks of a brief assessment of intellectual aptitudes for the identification of the IGC.

Prevalence of Developmental Dyslexia in Spanish University Students

A recent concern in the field of dyslexia studies is the lack of awareness and attention to university students suffering from this condition. If this problem is serious in countries where the relative opacity of the writing system allows for an early detection and, therefore, effective interventions, it is most critical in countries where transparent spelling makes such detection difficult, except in the most severe cases. In Spain, the diagnosis of dyslexia is rare among university-level adults. The present study pursues three aims: (a) to put forward a screening instrument for the detection of university students at risk of dyslexia, (b) to determine the ratio of university students that could be at risk of dyslexia by means of two different procedures, and (c) to create awareness for a disorder that causes hitherto unrecognized difficulties for an important subgroup of the college population. Six hundred and eighty-six university students in four different fields of study within the general area of Social Sciences from a public University in Madrid completed a Spanish-adapted version of a protocol including stress assignment, spelling words and nonwords, and timed phonological working memory of reading and writing task. Results showed that between 1.6% and 6.4% of this population could be at risk of suffering dyslexia. Such risk is not evenly distributed across the four fields of study. As for gender, the first criterion used yields 1.8 males at risk for every female, but the second criterion has as many males as females at risk. Women were significantly better than men in word spelling. Spelling was best predicted by the timed phonological working memory task of reading and writing.

Enhancing the comprehension of visual metaphors in individuals with intellectual disability with or without down syndrome

This study is the first to investigate the effectiveness of deep and shallow intervention programs in the acquisition of visual metaphor comprehension in individuals with non-specific intellectual disability (NSID; aged 15-59, N = 53) or Down syndrome (DS; aged 15-52, N = 50). The deep intervention program was based on dynamic assessment model for enhancing analogical thinking. The shallow intervention program involves memorizing a metaphorical relationship between pairs of pictures. Visual metaphor comprehension was measured by the construction of a metaphorical connection between pairs of pictures. The results indicated that both etiology groups exhibited poor understanding of visual metaphors before the intervention. A significant improvement was observed in both interventions and both etiology groups, with greater improvement among individuals who underwent the deep processing. Moreover, the latter procedure led to greater generalization ability. The results also indicated that vocabulary contributed significantly to understanding unstudied metaphors and that participants with poorer linguistic abilities exhibited greater improvement in their metaphorical thinking. Thus, individuals with ID with or without DS are able to recruit the higher-order cognitive abilities required for visual metaphor comprehension.

Analyzing Global Components in Developmental Dyscalculia and Dyslexia

The study examined whether developmental deficits in reading and numerical skills could be expressed in terms of global factors by reference to the rate and amount (RAM) and difference engine (DEM) models. From a sample of 325 fifth grade children, we identified 5 children with dyslexia, 16 with dyscalculia, 7 with a “mixed pattern,” and 49 control children. Children were asked to read aloud words presented individually that varied for frequency and length and to respond (either vocally or manually) to a series of simple number tasks (addition, subtraction, number reading, and number comparisons). Reaction times were measured. Results indicated that the deficit of children with dyscalculia and children with a mixed pattern on numerical tasks could be explained by a single global factor, similarly to the reading deficit shown by children with dyslexia. As predicted by the DEM, increases in task difficulty were accompanied by a corresponding increase in inter-individual variability for both the reading and numerical tasks. These relationships were constant across the four groups of children but differed in terms of slope and intercept on the x-axis, indicating that two different general rules underlie performance in reading and numerical skills. The study shows for the first time that, as previously shown for reading, also numerical performance can be explained with reference to a global factor. The advantage of this approach is that it takes into account the over-additivity effect, i.e., the presence of larger group differences in the case of more difficult conditions over and above the characteristics of the experimental conditions. It is concluded that reference to models such as the RAM and DEM can be useful in delineating the characteristics of the dyscalculic deficit as well as in the description of co-morbid disturbances, as in the case of dyslexia and dyscalculia.

Local and global processing in block design tasks in children with dyslexia or nonverbal learning disability

Visuo-constructive and perceptual abilities have been poorly investigated in children with learning disabilities. The present study focused on local or global visuospatial processing in children with nonverbal learning disability (NLD) and dyslexia compared with typically-developing (TD) controls. Participants were presented with a modified block design task (BDT), in both a typical visuo-constructive version that involves reconstructing figures from blocks, and a perceptual version in which respondents must rapidly match unfragmented figures with a corresponding fragmented target figure. The figures used in the tasks were devised by manipulating two variables: the perceptual cohesiveness and the task uncertainty, stimulating global or local processes. Our results confirmed that children with NLD had more problems with the visuo-constructive version of the task, whereas those with dyslexia showed only a slight difficulty with the visuo-constructive version, but were in greater difficulty with the perceptual version, especially in terms of response times. These findings are interpreted in relation to the slower visual processing speed of children with dyslexia, and to the visuo-constructive problems and difficulty in using flexibly-experienced global vs local processes of children with NLD. The clinical and educational implications of these findings are discussed.

Movement cognition and narration of the emotions treatment versus standard speech therapy in the treatment of children with borderline intellectual functioning: a randomized controlled trial

BACKGROUND

Borderline intellectual functioning (BIF) is defined as a "health meta-condition… characterized by various cognitive dysfunctions associated with an intellectual quotient (IQ) between 71 and 85 which determines a deficit in the individual's functioning both in the restriction of activities and in the limitation of social participation". It can be caused by many factors, including a disadvantaged background and prematurity. BIF affects 7-12% of primary school children that show academic difficulties due to poor executive functioning. In many children with BIF, language, movement and social abilities are also affected, making it difficult to take part in daily activities. Dropping out of school and psychological afflictions such as anxiety and depression are common in children with BIF. This study investigates whether an intensive rehabilitation program that involves all of the areas affected in children with BIF (Movement, Cognition and Narration of emotions, MCNT) is more effective than Standard Speech Therapy (SST).

METHODS

This is a multicenter interventional single blind randomized controlled study. Children aged between 6 to 11 years who attend a mainstream primary school and have multiple learning difficulties, behavioral problems and an IQ ranging between 85 to 70 have been enrolled. Participants are randomly allocated to one of three groups. The first group receives individual treatment with SST for 45 min, twice a week for 9 months. The second group receives the experimental treatment MCNT for 3 h per day, 5 days/ week for 9 months and children work in small groups. The third group consists of children on a waiting list for the SST for nine months.

DISCUSSION

BIF is a very frequent condition with no ad hoc treatment. Over the long term, there is a high risk to develop psychiatric disorders in adulthood. Due to its high social impact, we consider it very important to intervene during childhood so as to intercept the remarkable plasticity of the developing brain.

TRIAL REGISTRATION

"Study Let them grow: A new intensive and multimodal Treatment for children with borderline intellectual functioning based on Movement, Cognition and Narration of emotions", retrospectively registered in ISRCTN Register with ISRCTN81710297 at 2017-01-09.

The Contributions of Memory and Vocabulary to Non-Verbal Ability Scores in Adolescents with Intellectual Disability

It is usually assumed that performance on non-verbal intelligence tests reflects visual cognitive processing and that aspects of working memory (WM) will be involved. However, the unique contribution of memory to non-verbal scores is not clear, nor is the unique contribution of vocabulary. Thus, we aimed to investigate these contributions. Non-verbal test scores for 17 individuals with intellectual disability (ID) and 39 children with typical development (TD) of similar mental age were compared to determine the unique contribution of visual and verbal short-term memory (STM) and WM and the additional variance contributed by vocabulary scores. No significant group differences were found in the non-verbal test scores or receptive vocabulary scores, but there was a significant difference in expressive vocabulary. Regression analyses indicate that for the TD group STM and WM (both visual and verbal) contributed similar variance to the non-verbal scores. For the ID group, visual STM and verbal WM contributed most of the variance to the non-verbal test scores. The addition of vocabulary scores to the model contributed greater variance for both groups. More unique variance was contributed by vocabulary than memory for the TD group, whereas for the ID group memory contributed more than vocabulary. Visual and auditory memory and vocabulary contributed significantly to solving visual non-verbal problems for both the TD group and the ID group. However, for each group, there were different weightings of these variables. Our findings indicate that for individuals with TD, vocabulary is the major factor in solving non-verbal problems, not memory, whereas for adolescents with ID, visual STM, and verbal WM are more influential than vocabulary, suggesting different pathways to achieve solutions to non-verbal problems.

Cognitive Clusters in Specific Learning Disorder

The heterogeneity among children with learning disabilities still represents a barrier and a challenge in their conceptualization. Although a dimensional approach has been gaining support, the categorical approach is still the most adopted, as in the recent fifth edition of the Diagnostic and Statistical Manual of Mental Disorders. The introduction of the single overarching diagnostic category of specific learning disorder (SLD) could underemphasize interindividual clinical differences regarding intracategory cognitive functioning and learning proficiency, according to current models of multiple cognitive deficits at the basis of neurodevelopmental disorders. The characterization of specific cognitive profiles associated with an already manifest SLD could help identify possible early cognitive markers of SLD risk and distinct trajectories of atypical cognitive development leading to SLD. In this perspective, we applied a cluster analysis to identify groups of children with a Diagnostic and Statistical Manual-based diagnosis of SLD with similar cognitive profiles and to describe the association between clusters and SLD subtypes. A sample of 205 children with a diagnosis of SLD were enrolled. Cluster analyses (agglomerative hierarchical and nonhierarchical iterative clustering technique) were used successively on 10 core subtests of the Wechsler Intelligence Scale for Children-Fourth Edition. The 4-cluster solution was adopted, and external validation found differences in terms of SLD subtype frequencies and learning proficiency among clusters. Clinical implications of these findings are discussed, tracing directions for further studies.

The importance of working memory for school achievement in primary school children with intellectual or learning disabilities

BACKGROUND

Given the well-known relation between intelligence and school achievement we expect children with normal intelligence to perform well at school and those with intelligence deficits to meet learning problems. But, contrary to these expectations, some children do not perform according to these predictions: children with normal intelligence but sub-average school achievement and children with lower intelligence but average success at school. Yet, it is an open question how the unexpected failure or success can be explained.

AIMS

This study examined the role of working memory sensu Baddeley (1986) for school achievement, especially for unexpected failure or success.

METHOD AND PROCEDURES

An extensive working memory battery with a total of 14 tasks for the phonological loop, the visual-spatial sketchpad and central executive skills was presented in individual sessions to four groups of children differing in IQ (normal vs. low) and school success (good vs. poor).

OUTCOMES AND RESULTS

Results reveal that children with sub-average school achievement showed deficits in working memory functioning, irrespective of intelligence. By contrast, children with regular school achievement did not show deficits in working memory, again irrespective of intelligence.

CONCLUSIONS AND IMPLICATIONS

Therefore working memory should be considered an important predictor of academic success that can lead both to unexpected overachievement and failure at school. Individual working memory competencies should be taken into account with regard to diagnosis and intervention for children with learning problems.

Social Competence in Children with Borderline Intellectual Functioning: Delayed Development of Theory of Mind Across All Complexity Levels

Borderline intellectual functioning (BIF) is characterized by heterogeneous cognitive difficulties, with an intelligence quotient (IQ) between 70 and 85 points, and a failure to meet the developmental and sociocultural standards for personal independence and social responsibility required in daily life. The fact that this population still remain a marginal clinical category, with no ad hoc diagnostic and therapeutic approaches, has stimulated the present research. Our goal was to study children with BIF investigating the development of Theory of Mind (ToM) as a pillar of social competence. Children with BIF (N = 28, 16 male/12 female, and mean age 9.46 ± 1.26 years) and children with typical development (TD; N = 31, 17 male/14 female; mean age 8.94 years ± 0.99) underwent a neurocognitive assessment and a ToM assessment. Children with BIF showed a significant lower performance across all the levels of ToM development investigated compared to the control group, and a correlation between executive functions and the advanced levels of ToM reasoning. These results constitute a first step in the direction of defining the clinical profile of children with BIF concerning ToM development, opening the way to future interventions in order to support the developmental evolution of this population in an adaptive direction.

Role of Class III phosphoinositide 3-kinase in the brain development: possible involvement in specific learning disorders

Class III phosphoinositide 3-kinase (PIK3C3 or mammalian vacuolar protein sorting 34 homolog, Vps34) regulates vesicular trafficking, autophagy, and nutrient sensing. Recently, we reported that PIK3C3 is expressed in mouse cerebral cortex throughout the developmental process, especially at early embryonic stage. We thus examined the role of PIK3C3 in the development of the mouse cerebral cortex. Acute silencing of PIK3C3 with in utero electroporation method caused positional defects of excitatory neurons during corticogenesis. Time-lapse imaging revealed that the abnormal positioning was at least partially because of the reduced migration velocity. When PIK3C3 was silenced in cortical neurons in one hemisphere, axon extension to the contralateral hemisphere was also delayed. These aberrant phenotypes were rescued by RNAi-resistant PIK3C3. Notably, knockdown of PIK3C3 did not affect the cell cycle of neuronal progenitors and stem cells at the ventricular zone. Taken together, PIK3C3 was thought to play a crucial role in corticogenesis through the regulation of excitatory neuron migration and axon extension. Meanwhile, when we performed comparative genomic hybridization on a patient with specific learning disorders, a 107 Kb-deletion was identified on 18q12.3 (nt. 39554147-39661206) that encompasses exons 5-23 of PIK3C3. Notably, the above aberrant migration and axon growth phenotypes were not rescued by the disease-related truncation mutant (172 amino acids) lacking the C-terminal kinase domain. Thus, functional defects of PIK3C3 might impair corticogenesis and relate to the pathophysiology of specific learning disorders and other neurodevelopmental disorders. Acute knockdown of Class III phosphoinositide 3-kinase (PIK3C3) evokes migration defects of excitatory neurons during corticogenesis. PIK3C3-knockdown also disrupts axon outgrowth, but not progenitor proliferation in vivo. Involvement of PIK3C3 in neurodevelopmental disorders might be an interesting future subject since a deletion mutation in PIK3C3 was detected in a patient with specific learning disorders (SLD).

Utility of the General Ability Index (GAI) and Cognitive Proficiency Index (CPI) with survivors of pediatric brain tumors: Comparison to Full Scale IQ and premorbid IQ estimates

INTRODUCTION

Pediatric brain tumor survivors are at risk for working memory and processing speed impairment. The General Ability Index (GAI) provides an estimate of intellectual functioning that is less influenced by working memory and processing speed than a Full Scale IQ (FSIQ). The Cognitive Proficiency Index (CPI) provides a measure of efficient information processing derived from working memory and processing speed tasks. We examined the utility of the GAI and CPI to quantify neurocognitive outcomes in a sample of pediatric brain tumor survivors.

METHOD

GAI, CPI, and FSIQ scores from the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) were examined for 57 pediatric brain tumor survivors (ages 6-16 years) treated with cranial radiation therapy (RT).

RESULTS

GAI scores were higher than FSIQ and CPI scores, both p < .001. Lower CPI scores were associated with history of craniospinal irradiation and time since RT. Lower FSIQ and GAI scores were associated with higher RT dose and time since RT. The rate of clinically significant GAI-FSIQ discrepancies in our sample was greater than that observed in the WISC-IV standardization sample, p < .001. Estimated premorbid IQ scores were higher than GAI, p < .01, and FSIQ scores, p < .001.

CONCLUSIONS

Pediatric brain tumor survivors exhibit weaker cognitive proficiency than that expected for age, while general reasoning ability remains relatively spared. The GAI may be useful to quantify the intellectual potential of a survivor when appropriate accommodations are in place for relative cognitive proficiency weaknesses. The CPI may be a particularly sensitive outcome measure of treatment-related cognitive change in this population.

WISC-IV Intellectual Profiles in Italian Children With Specific Learning Disorder and Related Impairments in Reading, Written Expression, and Mathematics

The fifth edition of theDiagnostic and Statistical Manual of Mental Disordersgrouped specific learning disabilities in the single diagnostic category of specific learning disorder (SLD), with specifiers for impairments in reading, written expression, and mathematics. This study aimed at investigating the intellectual profile, assessed with the fourth edition of theWechsler Intelligence Scale for Children(WISC-IV), of 172 children with a diagnosis of SLD, compared to 74 clinical referral controls. WISC-IV intellectual functioning in children with SLD was characterized by a significant discrepancy between general ability and cognitive proficiency (General Ability Index [GAI] > Cognitive Proficiency Index [CPI]), and worse performances on the Similarities, Digit Span, Letter-Number Sequencing, and Coding subtests, supporting models of multiple cognitive deficits at the basis of neurodevelopmental disorders as SLD. GAI was the best and more conservative measure provided by the WISC-IV to identify intellectual functioning in children with SLD, and the intellectual discrepancy between GAI and CPI could be considered a "cognitive sign" for the presence of SLD in a single diagnostic category. Cognitive deficits differed in subtypes of impairment (reading, written expression, and mathematics), supporting their distinction for empirical, educational, and rehabilitative purposes. These findings need further replication in larger samples and in comparison to typically developing children.

Neuropsychological Profiles of Written Expression Learning Disabilities Determined by Concordance-Discordance Model Criteria

Children with specific learning disabilities (SLD) have disparate neuropsychological processing deficits that interfere with academic achievement in spelling, writing fluency, and/or written expression (WE). Although there are multiple potential causes of WE SLD, there is a paucity of research exploring this critical academic skill from a neuropsychological perspective. This study examined the neuropsychological profiles of WE SLD subtypes defined using the concordance-discordance model (C-DM) of SLD identification. Participants were drawn from a sample of 283 children (194 boys, 89 girls) aged 6 years to 16 years old (M(age) = 9.58 years, SD = 2.29 years) referred for comprehensive neuropsychological evaluations in school settings and subsequently selected based on C-DM determined spelling, writing fluency, and WE SLD. WE SLD subtypes differed on several psychomotor, memory, and executive function measures (F range = 2.48-5.07, p range = .049 to <.001), suggesting that these children exhibit distinct patterns of neuropsychological processing strengths and weaknesses. Findings have relevance for differential diagnosis of WE subtypes, discriminating WE SLD subtypes from low WE achievement, and developing differentiated evidence-based instruction and intervention for children with WE SLD. Limitations and future research will be addressed.

Abnormal development of sensory-motor, visual temporal and parahippocampal cortex in children with learning disabilities and borderline intellectual functioning

Borderline intellectual functioning (BIF) is a condition characterized by an intelligence quotient (IQ) between 70 and 85. BIF children present with cognitive, motor, social, and adaptive limitations that result in learning disabilities and are more likely to develop psychiatric disorders later in life. The aim of this study was to investigate brain morphometry and its relation to IQ level in BIF children. Thirteen children with BIF and 14 age- and sex-matched typically developing (TD) children were enrolled. All children underwent a full IQ assessment (WISC-III scale) and a magnetic resonance (MR) examination including conventional sequences to assess brain structural abnormalities and high resolution 3D images for voxel-based morphometry analysis. To investigate to what extent the group influenced gray matter (GM) volumes, both univariate and multivariate generalized linear model analysis of variance were used, and the varimax factor analysis was used to explore variable correlations and clusters among subjects. Results showed that BIF children, compared to controls have increased regional GM volume in bilateral sensorimotor and right posterior temporal cortices and decreased GM volume in the right parahippocampal gyrus. GM volumes were highly correlated with IQ indices. The present work is a case study of a group of BIF children showing that BIF is associated with abnormal cortical development in brain areas that have a pivotal role in motor, learning, and behavioral processes. Our findings, although allowing for little generalization to the general population, contribute to the very limited knowledge in this field. Future longitudinal MR studies will be useful in verifying whether cortical features can be modified over time even in association with rehabilitative intervention.