Impact of IQ Discrepancy on Executive Function in High-Functioning Autism: Insight into Twice Exceptionality

Everyday Executive Function in Preschoolers with Autism and Links with Intellectual Functioning, Adaptive Behavior, and Autism Symptoms

Impairments in executive function (EF) among individuals with autism spectrum disorder and their association with negative academic, adaptive, and social functioning outcomes have been widely reported over the past 20 years. However, there remains a lack of understanding of EF in autism during the preschool period, an age at which several crucial abilities (including EF) emerge. The present study therefore sought to document everyday EF in preschool-aged children with autism and its associations with other clinical characteristics. Parents rated the EF of their preschool-aged child with autism (M = 30-65 months, N = 288) using the Behavior Rating Inventory of Executive Function-Preschool Version (BRIEF-P; Gioia, G. A., Espy, K. A., & Isquith, P. K. (2003). Behavior Rating Inventory of Executive Function-Preschool Version. Psychological Assessment Resources.). Intellectual quotient, adaptive behavior, and autism symptom severity were also assessed. Preschoolers with ASD displayed impairments in everyday EF, particularly in relation with inhibition and working memory. Greater challenges in EF were strongly associated with lower levels of adaptive behavior and a higher severity of autistic symptoms. To a lesser extent, EF challenges were also associated with lower levels of intellectual functioning. The early assessment and detection of EF difficulties in preschoolers with ASD may assist in developing and integrating specific intervention targets to improve these essential abilities within existing early intervention programs for ASD. This could help to maximize their effectiveness and limit the extent of difficulties these children may face growing up.

Children with Autism Spectrum Disorder of All Ages, Levels of Symptom Severity and General Cognitive Ability Display Low Processing Speed Index Scores Warranting Special Educational Assistance

The processing speed index (PSI) of the Wechsler intelligence scale for children (WISC-IV) has been found to predict a child's level of academic functioning. The consistently reported PSI weakness in children with autism spectrum disorder (ASD) therefore warrants special assistance and attempts at compensation for the disadvantages associated with these children's low PSI. We investigated the association of PSI scores with age, general cognitive ability [as measured by full-scale IQ (FSIQ)], symptom severity and discrepancy between the WISC-IV indices verbal comprehension (VCI) and perceptual reasoning (PRI) in 101 school children with ASD. The PSI weakness in children with ASD was not related to age, FSIQ, VCI-PRI discrepancy or any of the symptom measures. These findings suggest that school children with ASD independent of their age, level of cognitive ability, VCI-PRI profile and most notably independent of their symptom severity should be entitled to special assistance and compensation in educational settings.

An Exploratory Study of Executive Function Development in Children with Autism, after Receiving Early Intensive Behavioral Training

Objective: To examine the development of executive functions, in preschool children with autism spectrum disorders (ASD), receiving early intensive behavioral training (EIBI). Method: Executive functions (EF) were assessed with The Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P), by parents and preschool teachers at the time of diagnostic assessment and after 15 months of EIBI intervention. Ten children with ASD (M = 2.9 years, nine males) participated in the study. Reliable Change Index scores were computed for each of the participants in order to investigate any significant change in BRIEF-P T-scores. Results: Three children showed a significant improvement in EF, based on parent ratings. Four children showed a significant improvement in EF based on preschool teacher ratings. Conclusion: Findings indicating a reliable improvement in one third of preschool children with ASD receiving EIBI are encouraging but need to be replicated in larger scale controlled studies.

IQ discrepancy differentiates levels of fine motor skills and their relationship in children with autism spectrum disorders

PURPOSE

We investigated 1) the impact of differences in intelligence quotient discrepancy (IQD) on motor skills of preschool-aged children with autism spectrum disorders (ASD); 2) the relationships between IQD and motor skills in preschool-aged children with ASD.

METHODS

A total of 127 ASD preschool-aged children were divided into three groups according to the size of the IQD: IQD within 1 standard deviation (1SD; EVENIQ; n=81), discrepantly higher verbal intelligence quotient (VIQ; n=22; VIQ>performance intelligence quotient [PIQ] above 1SD [≥15 points]), and discrepantly higher PIQ (n=24; PIQ>VIQ above 1SD [≥15 points]). Children's IQD and motor skills were determined with the Wechsler Preschool and Primary Scale of Intelligence™ - Fourth Edition and the motor subtests of the Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT), respectively.

RESULTS

One-way analysis of variance revealed significant group differences for the fine motor domain of the CDIIT and the visual-motor coordination subtest (F=3.37-4.38, p<0.05). Children with discrepantly higher PIQ were associated with better fine motor skills than were children with even IQD and those with discrepantly higher VIQ, and vice versa. IQD (PIQ - VIQ) had significant positive correlations with the fine motor domain and fine motor subtests of the CDIIT (r=0.18-0.29, p<0.05).

CONCLUSION

The IQD can identify different levels of fine motor skills in preschool-aged children with ASD. This study suggests important implications for clinicians, therapists, and researchers: discrepantly higher PIQ could be related to better visual-motor coordination, and discrepantly higher VIQ could be related to poor visual-motor coordination. Furthermore, the results support that when therapists are working with preschool-aged children with ASD who are developing fine motor skills or undertaking fine motor tasks related to visual-motor coordination, they may need to pay attention to the children's IQD.

Measuring Mentalizing Ability: A Within-Subject Comparison between an Explicit and Implicit Version of a Ball Detection Task

The concept of mentalizing has been widely studied, but almost exclusively through tasks with explicit instructions. Recent studies suggest that people also mentalize on a more implicit level. However, to our knowledge, no study to date has directly contrasted the effects of implicit and explicit mentalizing processes on an implicit dependent measure within-subjects. We implemented this by using two versions of an object detection task, differing only on secondary catch questions. We hypothesized that if explicit mentalizing relies on complementary processes beyond those underlying implicit mentalizing, this would be reflected in enhanced belief effects in the explicit version. Twenty-eight healthy adults watched movies in which, during the first phase, both they themselves and another agent formed a belief about the location of a ball, and although irrelevant, these beliefs could influence their ball detection reaction times in the second phase. After this response phase, there were occasional catch questions that were different for the explicit and implicit task version. Finally, self-report measures of autism spectrum disorder (ASD) symptomatology were included, as the literature suggests that ASD is related to a specific deficit in implicit mentalizing. Both in the explicit and implicit version, belief conditions had a significant effect on reaction times, with responses being slower when neither the participant nor the other agent expected the ball to be present compared to all other conditions. Importantly, after the implicit version, participants reported no explicit mentalizing awareness. In our neurotypical sample, ASD symptoms were not found to correlate with either explicit or implicit mentalizing. In conclusion, the reaction time patterns in the explicit and implicit version of the task show strikingly similar effects of mentalizing, indicating that participants processed beliefs to the same extent regardless of whether they mentalized explicitly or implicitly, with no additional effects for explicit processing.

Sex-Related Cognitive Profile in Autism Spectrum Disorders Diagnosed Late in Life: Implications for the Female Autistic Phenotype

Females with high-functioning ASD are known to camouflage their autistic symptoms better than their male counterparts, making them prone to being under-ascertained and delayed in diagnostic assessment. Thus far the underlying cognitive processes that enable such successful socio-communicative adaptation are not well understood. The current results show sex-related differences in the cognitive profile of ASD individuals, which were diagnosed late in life exclusively. Higher verbal abilities were found in males (n = 69) as opposed to higher processing speed and better executive functions in females with ASD (n = 38). Since both sexes remained unidentified during childhood and adolescence, these results are suggestive for sex-distinctive cognitive strategies as an alternative to typically-developed reciprocal social behavior and social mimicry in high functioning ASD.

Intelligence quotient discrepancy indicates levels of motor competence in preschool children at risk for developmental delays

PURPOSE

This study aimed to establish 1) whether a group difference exists in the motor competence of preschool children at risk for developmental delays with intelligence quotient discrepancy (IQD; refers to difference between verbal intelligence quotient [VIQ] and performance intelligence quotient [PIQ]) and 2) whether an association exists between IQD and motor competence.

METHODS

Children's motor competence and IQD were determined with the motor subtests of the Comprehensive Developmental Inventory for Infants and Toddlers and Wechsler Preschool and Primary Scale of Intelligence™ - Fourth Edition. A total of 291 children were included in three groups: NON-IQD (n=213; IQD within 1 standard deviation [SD]), VIQ>PIQ (n=39; VIQ>PIQ greater than 1 SD), and PIQ>VIQ (n=39; PIQ>VIQ greater than 1 SD).

RESULTS

The results of one-way analysis of variance indicated significant differences among the subgroups for the "Gross and fine motor" subdomains of the Comprehensive Developmental Inventory for Infants and Toddlers, especially on the subtests of "body-movement coordination" (F=3.87, P<0.05) and "visual-motor coordination" (F=6.90, P<0.05). Motor competence was significantly worse in the VIQ>PIQ group than in the NON and PIQ>VIQ groups. Significant negative correlations between IQD and most of the motor subtests (r=0.31-0.46, P<0.01) were found only in the VIQ>PIQ group.

CONCLUSION

This study demonstrates that 1) IQD indicates the level of motor competence in preschoolers at risk for developmental delays and 2) IQD is negatively associated with motor competence in preschoolers with significant VIQ>PIQ discrepancy. The first finding was that preschoolers with VIQ>PIQ discrepancy greater than 1 SD performed significantly worse on motor competence than did preschoolers without significant IQD and preschoolers with PIQ>VIQ discrepancy greater than 1 SD. However, preschoolers with significant PIQ>VIQ discrepancy performed better on motor competence than did preschoolers without significant IQD, though the difference was not statistically significant. The second finding was that preschoolers with larger VIQ>PIQ discrepancy had worse motor competence in visual-motor integration and body-movement coordination. Professionals should pay attention to the motor development of children with VIQ>PIQ discrepancy and evaluate children's IQD along with their motor competence.

Asperger syndrome and nonverbal learning difficulties in adult males: self- and parent-reported autism, attention and executive problems

A specific overlap between Asperger syndrome (AS) and nonverbal learning difficulties (NLD) has been proposed, based on the observation that, as a group, people with AS tend to have significantly higher verbal IQ (VIQ) than performance IQ (PIQ), one of the core features of NLD. The primary aim was to assess the longer term outcome of NLD--broken down into persistent and transient forms. The present study of 68 individuals was performed in the context of a larger prospective longitudinal study to late adolescence/early adult life of 100 boys with AS. Using self- and parent-report measures, we studied the longer term outcome of the NLD (defined as VIQ > PIQ by 15 points) as regards social communication, repetitive behaviour, attention, and executive function (EF) was studied. Three subgroups were identified: (1) Persistent NLD (P-NLD), (2) Childhood "only" NLD (CO-NLD) and (3) Never NLD (NO-NLD). The P-NLD group had the worst outcome overall. The CO-NLD group had better reported EF scores than the two other AS subgroups. There were no differences between the subgroups regarding social communication, repetitive behaviour, or attentional skills. Low PIQ increased the risk of ADHD symptoms. In the context of AS in males, P-NLD carries a relatively poor outcome, particularly with regard to self-reported EF. However, CO-NLD appears to entail a significantly better outcome. The results underscore the importance of analysing the cognitive profile both at diagnosis and after several years, so as to be able to formulate a realistic prognosis.

Executive functioning in children with ASD: an analysis of the BRIEF

The Behavior Rating Inventory of Executive Functions (BRIEF) screens for executive function deficits in 5- to 18-year-olds. Data of three autism subgroups, according to DSM-IV-TR criteria (N = 35 Autistic Disorder, N = 27 Asperger's Disorder and N = 65 PDD-NOS), were analyzed. The total group has elevated scores on almost all BRIEF scales. The Shift scale is clinically elevated, reflecting a deficit in cognitive flexibility. The BRIEF scales are not found to discriminate among the autism spectrum disorder (ASD) subgroups. The relation between BRIEF and IQ is complex. Possible influencing factors are discussed. Finally, it is recommended to omit the Negativity scale as a validity index in children with ASD and to consider a high score on this index as a unique characteristic of their BRIEF profile, reflecting rigidity problems.

Age related differences of executive functioning problems in everyday life of children and adolescents in the autism spectrum

Numerous studies investigated executive functioning (EF) problems in people with autism spectrum disorders (ASD) using laboratory EF tasks. As laboratory task performances often differ from real life observations, the current study focused on EF in everyday life of 118 children and adolescents with ASD (6-18 years). We investigated age-related and individual differences in EF problems as reported by parents on the Behavioral Rating Inventory Executive Functions (BRIEF: Gioia et al. in Behavior rating inventory of executive function. Psychological Assessment Resources, Odesse 2000), and examined the association with autism severity. Inhibition problems were mostly found in the youngest group (6- to 8-year-olds), whereas problems with planning where more evident for 12- to 14-year-olds as compared to 9- to 11-year-olds. In a subsample of participants meeting the ADOS ASD cut-off criteria the age related differences in planning were absent, while problems with cognitive flexibility were less apparent in 15- to 18-year-olds, compared to 9- to 11-, and 12- to 14-year olds. EF problems surpassing the clinical cutoff were only observed in 20% (planning) to 51% (cognitive flexibility) of the children and adolescents, and no relation was found with ASD symptom severity. This underlines the heterogeneous nature of ASD.

A systems biology approach to identify intelligence quotient score-related genomic regions, and pathways relevant to potential therapeutic treatments

Although the intelligence quotient (IQ) is the most popular intelligence test in the world, little is known about the underlying biological mechanisms that lead to the differences in human. To improve our understanding of cognitive processes and identify potential biomarkers, we conducted a comprehensive investigation of 158 IQ-related genes selected from the literature. A genomic distribution analysis demonstrated that IQ-related genes were enriched in seven regions of chromosome 7 and the X chromosome. In addition, these genes were enriched in target lists of seven transcription factors and sixteen microRNAs. Using a network-based approach, we further reconstructed an IQ-related pathway from known human pathway interaction data. Based on this reconstructed pathway, we incorporated enriched drugs and described the importance of dopamine and norepinephrine systems in IQ-related biological process. These findings not only reveal several testable genes and processes related to IQ scores, but also have potential therapeutic implications for IQ-related mental disorders.

Differences between Children with Dyslexia Who Are and Are Not Gifted in Verbal Reasoning

New findings are presented for children in grades 1 to 9 who qualified their families for a multi-generational family genetics study of dyslexia (impaired word decoding/spelling) who had either superior verbal reasoning (n=33 at or above 1 2/3 standard deviation, superior or better range; 19% of these children) or average verbal reasoning (n=31 below population mean, but above - 2/3 standard deviation, average range; 18% of these children). Evidence-based rationale and results supporting the tested hypotheses are provided: (a) twice exceptional students with superior verbal reasoning and dyslexia significantly outperformed those with average verbal reasoning and dyslexia on reading, spelling, morphological, and syntactic skills, (b) but not on verbal working-memory behavioral markers of genetically based dyslexia related to impaired phonological and orthographic word-form storage and processing, naming orthographic symbols (phonological loop), writing orthographic symbols (orthographic loop), and supervisory attention (focus, switch, sustain, or monitor attention). Superior verbal reasoning may mask dyslexia if only very low achievement is used to identify this disorder of oral word reading and written spelling. Instruction for twice exceptional students who have dyslexia, but are also verbally gifted, should focus not only on oral word reading and written spelling but also the impaired working memory components within intellectually engaging lesson sets. These findings for gifted students with dyslexia are situated within the broader context of the many kinds of twice exceptionalities related to specific learning disabilities that exist in school-age children and youth.

IQdb: an intelligence quotient score-associated gene resource for human intelligence

Intelligence quotient (IQ) is the most widely used phenotype to characterize human cognitive abilities. Recent advances in studies on human intelligence have identified many new susceptibility genes. However, the genetic mechanisms involved in IQ score and the relationship between IQ score and the risk of mental disorders have won little attention. To address the genetic complexity of IQ score, we have developed IQdb (http://IQdb.cbi.pku.edu.cn), a publicly available database for exploring IQ-associated human genes. In total, we collected 158 experimental verified genes from literature as a core dataset in IQdb. In addition, 46 genomic regions related to IQ score have been curated from literature. Based on the core dataset and 46 confirmed linked genomic regions, more than 6932 potential IQ-related genes are expanded using data of protein–protein interactions. A systematic gene ranking approach was applied to all the collected and expanded genes to represent the relative importance of all the 7090 genes in IQdb. Our further systematic pathway analysis reveals that IQ-associated genes are significantly enriched in multiple signal events, especially related to cognitive systems. Of the 158 genes in the core dataset, 81 are involved in various psychotic and mental disorders. This comprehensive gene resource illustrates the importance of IQdb to our understanding on human intelligence, and highlights the utility of IQdb for elucidating the functions of IQ-associated genes and the cross-talk mechanisms among cognition-related pathways in some mental disorders for community.

Database URL: http://IQdb.cbi.pku.edu.cn.