Cognitive control in children with learning disabilities: neuromarker for deficient executive functions

Longitudinal investigation in children and adolescents with ADHD and healthy controls: A 2-year ERP study

Cross-sectional group comparisons have shown altered neurocognitive and neurophysiological profiles in individuals with attention-deficit/hyperactivity disorder (ADHD). We report a two-year longitudinal observational study of ADHD children and adolescents (N = 239) regarding ADHD symptoms, behavioral metrics, and event-related potentials (ERP) and compared them to healthy controls (N = 91). The participants were assessed up to five times with a cued Go/NoGo task while ERPs were recorded. We fitted the trajectories of our variables of interest with univariate and bivariate latent growth curve models. At baseline, the ADHD group had increased reaction time variability, higher number of omission and commission errors, and attenuated CNV and P3d amplitudes compared to controls. The task performance in terms of behavioral metrics improved in both groups over two years; however, with differential patterns: the decrease in reaction time and omission errors were stronger in the control group, and the reduction of commission errors was more substantial in the ADHD group. The cueP3, CNV, and N2d amplitudes changed slightly over two years, with negligible differences between both groups. Furthermore, the parent-rated symptom burden in the ADHD group decreased by 22 % (DSM-5-based questionnaire). We did not identify any associations between the changes in symptoms and the changes in the behavioral or neurophysiological metrics. The lack of association between the changes in symptoms and the behavioral or ERP metrics supports the trait liability hypothesis, which claims that the neurocognitive deficits are independent of symptom alleviation. Furthermore, the change in symptom burden was substantial, questioning the stability of the reported ADHD symptoms.

The Effect of Perceptual-Motor Training on Executive Functions in Children with Non-Verbal Learning Disorder

PURPOSE

Research shows an atypical cognitive process in children with nonverbal learning disorder (NLD) compared to typically developing children, but a wealth of information indicates that physical activity can influence cognitive processes. However, little is known about the effects of perceptual-motor training and its impact on the cognitive process of children with NLD. Thus, the major goals of this study are to compare the executive functions (EFs) in children with NLD with typically developing children and then to investigate the effect of perceptual-motor training on EFs of children with NLD.

METHODS

To achieve the first goal, 400 typically developing (IQ >80) and NLD children (7-13 years old) were randomly selected in the city of Mashhad, Iran, during the period 2017-2018. As for the second goal, 50 children with NLD were randomly assigned to an experimental or control group. To evaluate executive functions, Delis-Kaplan executive function system test was used at the pretest, posttest, and 3-month follow-up. The experimental group received the Werner and Reini's perceptual-motor training program in sixteen 45-min sessions (three sessions per week), but the control group did not receive any intervention.

RESULTS

The results showed that children with NLD were significantly weaker than typically developing children in London Tower Test (t (38) = -4.662, p <0.01), Trail Making Test (t (33.926) = -3.11, p <0.01), Card Sorting Test (t (38) = -3.427, p <0.01), and Stroop Color Test (t (30.035) = -5.876, p <0.01). The Pilates training had an obvious effect on enhancing the performance of participants in the experimental group (p<0.001), but similar results were not observed in the control group.

CONCLUSION

Children with NLD have problems in EFs, but perceptual-motor training can be used as an effective intervention for these children.

The Effect of Background Music on Inhibitory Functions: An ERP Study

The influence of background music on cognitive functions is still a matter of debate. In this study, we investigated the influence of background music on executive functions (particularly on inhibitory functions). Participants completed a standardized cued Go/NoGo task during three different conditions while an EEG was recorded (1: with no background music, 2: with relaxing, or 3: with exciting background music). In addition, we collected reaction times, omissions, and commissions in response to the Go and NoGo stimuli. From the EEG data, event-related potentials (ERPs) were calculated for the Go and NoGo trials. From these ERPs, the N2 and P3 components were specifically analyzed since previous studies have shown that these components (and particularly the Go-NoGo difference waves) are strongly associated with inhibitory functions. The N2 and P3 components of the difference waves (N2d and P3d) were used for statistical analyses. The statistical analyses revealed no differences between the three conditions in terms of amplitudes and latencies of the N2d and P3d components. In addition, reaction times, omissions, and commissions were comparable across all conditions. Our results suggest that in the context of this paradigm, music as background acoustic stimulation has no detrimental effects on the performance of a Go/NoGo task and neural underpinnings.