ABSTRACT
Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are associated with varied executive function (EF) difficulties. Callous-unemotional (CU) traits, a proposed antecedent of adult psychopathy, are often associated with intact or enhanced EF. Here we test whether CU traits may therefore modulate EF in ASD and ADHD, in which EF is typically impaired. We collected CU traits and measured event-related potentials (ERPs) that index EF during a cued-continuous performance test (CPT-OX) in boys with ASD, ADHD, comorbid ASD+ADHD and typical controls. We examined attentional orienting at cues (Cue-P3), inhibitory processing at non-targets (NoGo-P3) and conflict monitoring between target and non-target trials (Go-N2 vs. NoGo-N2). In children with ASD, higher CU traits were associated with an enhanced increase in N2 amplitude in NoGo trials compared to Go trials, which suggests relatively superior conflict monitoring and a potential cognitive strength associated with CU traits. The results emphasise the importance of considering the effects of co-occurring traits in the assessment of heterogeneity of EF profiles in neurodevelopmental disorders.
Subject(s)
Attention Deficit Disorder with Hyperactivity/physiopathology , Autism Spectrum Disorder/physiopathology , Executive Function/physiology , Adolescent , Child , Evoked Potentials , Female , Humans , Male , Pilot ProjectsABSTRACT
BACKGROUND: Substantial overlap has been reported between attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Deficits in executive function (EF) are characteristic of both disorders but these impairments have not been compared directly across pure and co-morbid cases using event-related potentials (ERPs). METHOD: Behavioural parameters and ERPs were recorded during a flankered cued-continuous performance test (CPT-OX) administered to 8-13-year-old boys with ASD (n = 19), ADHD (n = 18), co-morbid ASD + ADHD (n = 29) and typically developing controls (TD; n = 26). Preparatory processing (contingent negative variation, CNV) and attentional orienting (Cue-P3) at cues, response execution at targets (Go-P3), inhibitory processing at non-targets (NoGo-P3) and conflict monitoring between target and non-target trials (Go-N2 v. NoGo-N2) were examined. RESULTS: Categorical diagnoses and quantitative trait measures indicated that participants with ADHD (ADHD/ASD + ADHD) made more omission errors and exhibited increased reaction-time (RT) variability and reduced amplitude of the Cue-P3 and NoGo-P3 compared to TD/ASD participants. Participants with ASD (ASD/ ASD + ADHD) demonstrated reduced N2 enhancement from Go to NoGo trials compared to TD/ADHD participants. Participants with ASD-only displayed enhanced CNV amplitude compared to ASD + ADHD and TD participants. CONCLUSIONS: Children with ADHD show deficits in attentional orienting and inhibitory control whereas children with ASD show abnormalities in conflict monitoring and response preparation. Children with co-morbid ASD + ADHD present as an additive co-occurrence with deficits of both disorders, although non-additive effects are suggested for response preparation. Measuring ERPs that index attention and inhibition is useful in disentangling cognitive markers of ASD and ADHD and elucidating the basis of co-occurring ASD + ADHD to guide clinical assessment.
Subject(s)
Attention Deficit Disorder with Hyperactivity/physiopathology , Attention/physiology , Child Development Disorders, Pervasive/physiopathology , Evoked Potentials/physiology , Inhibition, Psychological , Psychomotor Performance/physiology , Adolescent , Attention Deficit Disorder with Hyperactivity/epidemiology , Child , Child Development Disorders, Pervasive/epidemiology , Comorbidity , Contingent Negative Variation/physiology , Event-Related Potentials, P300/physiology , Humans , MaleABSTRACT
UNLABELLED: BACKGROUND AND THE PURPOSE OF STUDY: Galanthus transcaucasicus Fomin (Amaryllidaceae) is an endemic species to the Caucasia and Alborz mountains in Iran which locally named "Gole-Barfi". While there are many reports on pharmacological activities of Galanthus species' alkaloids, there is no report on G. transcaucasicus and this article is the first phytochemical study on this species. METHODS: Extracted alkaloids from G. transcaucasicus bulbs were isolated using different chromatographic methods and the structures of the components were determined by physical and spectroscopic data. RESULTS: Five isoquinoline type alkaloids namely galanthamine (8.04%), narwedine (6.90%), lycorine (19.48%), caranine (3.45%) and tazettine (5.75%) of total alkaloid extract were isolated from the bulbs of Galanthus transcaucasicus Fomin. MAJOR CONCLUSION: Because of the presence of biologically active alkaloids especially galanthamine and the major alkaloid lycorine in Gol-e-Barfi, the plant may be used as a natural source for pharmaceutical purposes.
