Intelligence and Executive Functions: A Comprehensive Assessment of Intellectually Gifted Children

OBJECTIVE

Executive functions (EFs) play a key role in cognitive and behavioral functioning. Their multiple forms and implications for daily life behaviors mean they are sometimes equated with intelligence. Several elements even suggest that intellectually gifted children (IGC) may present better executive functioning than typical developing children (TDC, children with intelligence in the average range). However, no study has ever completely tested this hypothesis by a comprehensive assessment of EFs in IGC.

METHOD

Results of 30 IGC and 35 TDC aged from 6 to 16 years old were compared through a comprehensive assessment of EFs (inhibition, flexibility, and planning), comprising performance-based and daily life measures.

RESULTS

IGC did not differ from TDC in EF performance-based measures. However, they scored higher in parents' and some teachers' ratings, suggesting higher indicators of difficulties in daily life.

CONCLUSIONS

Contrary to expectations, high intellectual level does not appear to be associated with superior EFs. Surprisingly, parents and teachers of IGC reported more complaints about their executive functioning in everyday life. We put forward different hypotheses to explain this contrast. Further research is needed to better understand this phenomenon, in which neuropsychology has a fundamental role to play.

Associations of executive and functional outcomes with full-score intellectual quotient among ADHD adults

Associations between executive and functional impairment, intelligence, and attention deficit hyperactivity disorder (ADHD) have been scarcely investigated among adult populations and lead to inconsistent results. This study tested the impact of intellectual level on executive and functional impairment in a clinical sample of adults diagnosed with ADHD. Participants were recruited in a specialized center for the diagnosis and treatment of ADHD (n=66, mean age=27.9 ± 10.8). Measures included intellectual quotient (IQ, Wechsler Adult Intelligence Scale) categorized as ≤110 or >110, the continuous performance test (CPT3^TM), grade retention, educational attainment, and having an activity (job or studies). Participants with a higher IQ had significantly better functional outcomes than participants with a standard IQ: higher educational attainment, lower grade retention, and often having an activity. Participants with higher IQ performed significantly better on all CPT variables assessing executive functioning. Intelligence seemed to work as a protective factor for executive and functional outcomes in a clinical population of ADHD adults and might reduce long-lasting detrimental consequences in life.

First report of two successive deletions on chromosome 15q13 cytogenetic bands in a boy and girl: additional data to 15q13.3 syndrome with a report of high IQ patient

15q13.3 syndrome is associated with a wide spectrum of neurological disorders. Among a cohort of 150 neurodevelopmental cases, we identified two patients with two close proximity interstitial hemizygous deletions on chromosome 15q13. Using high-density microarrays, we characterized these deletions and their approximate breakpoints. The second deletion in both patients overlaps in a small area containing CHRNA7 where the gene is partially deleted. The CHRNA7 is considered a strong candidate for the 15q13.3 deletion syndrome's pathogenicity. Patient 1 has cognitive impairment, learning disabilities, hyperactivity and subtle dysmorphic features whereas patient 2 has mild language impairment with speech difficulty, mild dysmorphia, heart defect and interestingly a high IQ that has not been reported in 15q13.3 syndrome patients before. Our study presents first report of such two successive deletions in 15q13.3 syndrome patients and a high IQ in a 15q13.3 syndrome patient. Our study expands the breakpoints and phenotypic features related to 15q13.3 syndrome.

No significant brain volume decreases or increases in adults with high-functioning autism spectrum disorder and above average intelligence: a voxel-based morphometric study

Autism spectrum disorder (ASD) is increasingly being recognized as an important issue in adult psychiatry and psychotherapy. High intelligence indicates overall good brain functioning and might thus present a particularly good opportunity to study possible cerebral correlates of core autistic features in terms of impaired social cognition, communication skills, the need for routines, and circumscribed interests. Anatomical MRI data sets for 30 highly intelligent patients with high-functioning autism and 30 pairwise-matched control subjects were acquired and analyzed with voxel-based morphometry. The gray matter volume of the pairwise-matched patients and the controls did not differ significantly. When correcting for total brain volume influences, the patients with ASD exhibited smaller left superior frontal volumes on a trend level. Heterogeneous volumetric findings in earlier studies might partly be explained by study samples biased by a high inclusion rate of secondary forms of ASD, which often go along with neuronal abnormalities. Including only patients with high IQ scores might have decreased the influence of secondary forms of ASD and might explain the absence of significant volumetric differences between the patients and the controls in this study.