Objective: Individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) are often characterized as inconsistent across many contexts. ADHD is also associated with deficits in executive function. We examined the relationships between response time variability on five brief computer tasks to parents’ ratings of ADHD-related features and executive function in a group of children with a broad range of ADHD symptoms from none to full diagnosis. Methods: We tested 98 children (mean age 9.9±1.4 yrs; 66 boys) from community clinics on short Tasks of Executive Control (TEC) and the Eriksen Flanker Task, while a parent completed the Conners Parent Rating Scale and Behavior Rating Inventory of Executive Function. Results: Variability for two of the TEC tasks explained significant proportions of the variance of all five ADHD-related Conners subscales and several executive function subscales. By contrast, variability on the flanker task or mean response times for any task were not associated with any rating scale. Conclusions: The significant dimensional relationships observed between variability measures and parent ratings support the utility of response time variability as an objective measure in ADHD and aspects of executive functioning that is superior to response time means or accuracy measures.

Abnormal patterns of touch processing have been linked to core symptoms in ASD. This study examined the relation between tactile processing patterns and social problems in 44 children and adolescents with ASD, aged 6-14 (M = 8.39 ± 2.35). Multiple linear regression indicated significant associations between touch processing and social problems. No such relationships were found for social problems and autism severity. Within touch processing, patterns of hyper-responsiveness and hypo-responsiveness best predicted social problems, whereas sensory-seeking did not. These results support that atypical touch processing in individuals with ASD might be contributing to the social problems they present. Moreover, it the need to explore more in depth the contribution of sensory features to the ASD phenotype.

Greater intra-subject variability (ISV) in response time is a heritable endophenotype of Attention-Deficit/Hyperactivity Disorder (ADHD). Spontaneous low frequency oscillations (LFO; 0.01–0.1 Hz) observed in brain functional magnetic resonance signals might account for such behavioral variability. Recently, we demonstrated that ISV in response time (RT) explained ratings of ADHD symptoms. Building on this finding, here we hypothesized that LFO in RT time-series would explain these ratings, both independently and in addition to RT coefficient of variation (CV). To measure RT-LFO, we applied Morlet wavelet transform to the previously collected RT data. Our community sample consisted of 98 children (including 66 boys, mean age 9.9±1.4 years), who completed four computer Tasks of Executive Control. Conners’ Parent Rating Scale ratings were obtained. RT-LFO of three tasks significantly explained ratings of inattention, hyperactivity and three global Conners subscales. Additionally, RT-LFO during two tasks that included an inhibitory component increased the proportions of variance explained in subscales of both inattention and hyperactivity/impulsivity, beyond the effects of RT-CV. Three specific low frequency bands (Slow 5: 0.01-0.027 Hz; Slow 4: 0.027-0.073 Hz; Slow 3: 0.073-0.20 Hz) were strongly related to the ADHD scales. We conclude that RT-LFO predict dimensional ratings of ADHD symptoms both independently and in addition to RTCV. Results suggest that frequency analyses are a suitable methodology to link behavioral responses to putative underlying physiological processes.

Key Clinical MessageWe report on a male patient with severe autistic disorder, lack of oral language, and dysmorphic features who carries a rare interstitial microdeletion of 4.96 Mb at chromosome 6q14.1-q15. The patient also harbors a maternally inherited copy number gain of 1.69 Mb at chromosome Xp22.31, whose pathogenicity is under debate.