Componentes de las pruebas de atención y función ejecutiva en niños con trastorno por déficit de atención/hiperactividad

ADHD Endophenotypes in Caribbean Families

Objective: The aim of this study is to contrast the genetics of neuropsychological tasks in individuals from nuclear families clustering ADHD in a Caribbean community. Method: We recruited and clinically characterized 408 individuals using an extensive battery of neuropsychological tasks. The genetic variance underpinning these tasks was estimated by heritability. A predictive framework for ADHD diagnosis was derived using these tasks. Results: We found that individuals with ADHD differed from controls in tasks of mental control, visuospatial ability, visuoverbal memory, phonological and verbal fluency, verbal and semantic fluency, cognitive flexibility, and cognitive ability. Among them, tasks of mental control, visuoverbal memory, phonological fluency, semantic verbal fluency, and intelligence had a significant heritability. A predictive model of ADHD diagnosis using these endophenotypes yields remarkable classification rate, sensitivity, specificity, and precision values (above 80%). Conclusion: We have dissected new cognitive endophenotypes in ADHD that can be suitable to assess the neurobiological and genetic basis of ADHD.

Verbal fluency in right brain damage: dissociations among production criteria and duration

This study aimed to verify dissociations in the performance of verbal fluency tasks with different production criteria and duration following vascular right-hemisphere damage. We tested the hypothesis that longer fluency tasks would be more sensitive in identifying deficits in the sample. The relationship between verbal fluency performance and sustained attention was also investigated. Forty adults with vascular right-hemisphere damage were assessed using verbal fluency tasks with three different production criteria (unconstrained, phonemic, and semantic fluencies from the Montreal Communication Evaluation Battery). Performance deficits in 1-min and 2-min fluency tasks were calculated (Z score) and compared (chi-square). Results did not suggest a difference in sensitivity between the task lengths in detecting cognitive impairment. However, double dissociations were found, highlighting the contribution of extended verbal fluency tasks to neuropsychological assessment. Analyses also showed that participants exhibited greater levels of impairment in the semantic fluency task. No relationship was identified between performance in sustained attention tasks and verbal fluency tasks, regardless of the latter's duration. The combined use of longer and shorter fluency tasks in the assessment of patients with right brain damage may contribute to the identification of different executive function impairments in this sample.

Structure and Invariance of Executive Functioning Tasks across Socioeconomic Status: Evidence from Spanish-Speaking Children

The aim of the present study was to analyze the latent structure of executive functions (EFs) in Spanish-speaking children and to test measurement invariance across socioeconomic status (SES). We sampled 248 children, aged 8 to 12, who were divided into two groups: 124 children from a medium socioeconomic status (MSS) and 124 children from a low socioeconomic status (LSS). We applied a neuropsychological battery consisting of various EF tasks and performed confirmatory factor analysis (CFA) and multi-group CFA (MGCFA). CFA showed best fit for the three factor solution: (a) Working memory, (b) Cognitive flexibility, and (c) Inhibition. Moreover, the MGCFA revealed that the three-factor solution was invariant (configural, metric, and structural) across SES, allowing valid comparison between the groups (MSS and LSS) of factors. Finally, bifactorial MANOVA revealed a significant effect of SES and group age but not for the interaction between the two in the three EF dimensions indicative of quantitative group differences. Results are discussed in terms of the dimensional nature of the EF construct and the effects of SES on executive functioning.

Executive dysfunction screening and intelectual coefficient measurement in children with attention deficit hyperactivity disorder

OBJECTIVE: To perform a complete Intelligence quotient (IQ) measurement (verbal, performance, and total) and subsequently, to compare executive function (EF) measurements in subgroups of children with attention deficit-hyperactivity disorder (ADHD) with a control group. METHOD: We studied a group of children from 7-12 years of age from public elementary schools. Children were selected by means of Diagnostic and Statistical Manual of Mental Disorders-IV-Revised (DSM-IV-R) parent and teacher questionnaires for ADHD. EFs were screened by Weschler Intelligence Scale for Children (WISC-R) performance intelligence quotient (IQ) determination of the following sub-tests: picture completion; block designs, and object assembly tests. Simultaneously, total (T-), performance (P-), and verbal (V-) IQs were measured for each patient. RESULTS: We studied 26 control subjects, and 35 children with ADHD. Numbers of children in each ADHD sub-type group were as follows: 15 in the combined group (-C), 13 in the inattentive group (-I), and 7 in hyperactivity group (-H). We found significant lower EF scores in picture arrangement (F=3.76, df 3,57, p=0.01), block design (F=4.55, df 3,57, p<0.01), and object assembly (F=4.52, df 3,57, p<0.01). Post-hoc analysis showed that differences were located among ADHD-C, ADHD-I, and ADHD-H groups when compared with controls. We found significantly lower cognitive scores in the ADHD-I group as follows: P-IQ (F=3.57, df 3,57, p=0.02), and T-IQ (F=2.90, df 3,57, p=0.04). CONCLUSION: Our results showed that screening of EF alteration in children with ADHD is easy and rapid by means of certain P-IQ determination sub-scales of the WISC test; moreover, complementary IQ determination can be measured simultaneously. Overall, children with ADHD exhibited an EF alteration. ADHD-I children demonstrated lower P-IQ, and T-IQ scores than control children.