ABSTRACT
There has been debate over whether disruptions in the mirror neuron system (MNS) play a key role in the core social deficits observed in autism spectrum disorders (ASD). EEG mu suppression during the observation of biological actions is believed to reflect MNS functioning, but understanding of the developmental progression of the MNS and EEG mu rhythm in both typical and atypical development is lacking. To provide a more thorough and direct exploration of the development of mu suppression in individuals with ASD, a sample of 66 individuals with ASD and 51 typically developing individuals of 6-17 years old were pooled from four previously published studies employing similar EEG methodology. We found a significant correlation between age and mu suppression in response to the observation of actions, both for individuals with ASD and typical individuals. This relationship was not seen during the execution of actions. Additionally, the strength of the correlation during the observation of actions did not significantly differ between groups. The results provide evidence against the argument that mirror neuron dysfunction improves with age in individuals with ASD and suggest, instead, that a diagnosis-independent developmental change may be at the root of the correlation of age and mu suppression.
Subject(s)
Child Development Disorders, Pervasive/complications , Cognition Disorders/etiology , Contingent Negative Variation/physiology , Neural Inhibition/physiology , Observation , Adolescent , Child , Cognition Disorders/diagnosis , Electroencephalography , Female , Humans , Male , Photic Stimulation , Statistics, NonparametricABSTRACT
Screening instruments for autism spectrum disorder (ASD) often generate many false positives. It is argued that these children may have other developmental difficulties and are also in need of thorough assessment and early intervention. The current study looked at the predictive validity of positive screens on the Checklist for Early Signs of Developmental Disorders (CESDD) and the Early Screening of Autistic Traits questionnaire (ESAT) at age 2 towards language, cognitive function, and symptom severity at age 4. Children who screened positive on the ESAT scored lower for both language and cognitive functioning at age 4 compared with children who screened negative on the ESAT. Also, the more signs of ASD that were recognized on the CESDD or ESAT, the lower the scores for language and cognitive functioning at age 4. False positive screens could be differentiated from true positive screens on the CESDD only in symptom severity score on the Autism Diagnostic Observation Schedule (ADOS). It seems that early screeners for ASD also detect children with other developmental disorders and that diagnostic instruments such as the ADOS are warranted to differentiate between children with ASD and other developmental problems.
Subject(s)
Child Development Disorders, Pervasive/diagnosis , Language Development , Mass Screening/standards , Checklist , Child Development Disorders, Pervasive/classification , Child, Preschool , Cognition , Diagnosis, Differential , False Positive Reactions , Female , Humans , Language Development Disorders , Male , Predictive Value of Tests , Psychiatric Status Rating Scales , Severity of Illness IndexABSTRACT
Several screening instruments for ASD in young children were developed during the last decades. Only few studies compare the discriminative power of these instruments in the same sample. In particular comparisons of instruments that use different informants are scarce in young children. The current study compared the discriminant ability of the Checklist for Early Signs of Developmental Disorders (CESDD) filled out by child care workers with that of frequently used parent questionnaires in a sample of 357 children between 5.57 and 48.13 months old who showed signs of ASD or language delay. The discriminant power of the CESDD was as good as that of parent questionnaires. Therefore, inclusion of child care workers in the early detection of ASD seems promising.
Subject(s)
Caregivers , Child Development Disorders, Pervasive/diagnosis , Early Diagnosis , Mass Screening/methods , Parents , Checklist , Child Care , Child, Preschool , Communication , Female , Humans , Infant , Interpersonal Relations , Male , Surveys and QuestionnairesABSTRACT
A new screening instrument for ASD was developed that can be filled out by child care workers: the Checklist for Early Signs of Developmental Disorders (CESDD). The predictive validity of the CESDD was evaluated in a population of 6,808 children between 3 and 39 months attending day-care centres in Flanders. The CESDD had a sensitivity of .80 and a specificity of .94. Based on the screening procedure used in this study, 41 children were diagnosed with ASD or got a working diagnosis of ASD. Thus, including child care workers' report on signs of ASD in screening procedures can help to identify cases of ASD at a young age.
Subject(s)
Child Day Care Centers , Child Development Disorders, Pervasive/diagnosis , Developmental Disabilities/diagnosis , Belgium , Checklist , Child, Preschool , Humans , Mass Screening , Population SurveillanceABSTRACT
OBJECTIVE: The effects of a promising pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD), atomoxetine, were studied on executive functions in both ADHD and reading disorder (RD) because earlier research demonstrated an overlap in executive functioning deficits in both disorders. In addition, the effects of atomoxetine were explored on lexical decision. METHODS: Sixteen children with ADHD, 20 children with ADHD + RD, 21 children with RD, and 26 normal controls were enrolled in a randomized placebo-controlled crossover study. Children were measured on visuospatial working memory, inhibition, and lexical decision on the day of randomization and following two 28-day medication periods. RESULTS: Children with ADHD + RD showed improved visuospatial working memory performance and, to a lesser extent, improved inhibition following atomoxetine treatment compared to placebo. No differential effects of atomoxetine were found for lexical decision in comparison to placebo. In addition, no effects of atomoxetine were demonstrated in the ADHD and RD groups. CONCLUSION: Atomoxetine improved visuospatial working memory and to a lesser degree inhibition in children with ADHD + RD, which suggests differential developmental pathways for co-morbid ADHD + RD as compared to ADHD and RD alone. CLINICAL TRIAL REGISTRY: B4Z-MC-LYCK, NCT00191906; http://clinicaltrials.gov/ct2/show/NCT00191906.
Subject(s)
Adrenergic Uptake Inhibitors/therapeutic use , Attention Deficit Disorder with Hyperactivity/drug therapy , Decision Making/drug effects , Dyslexia/drug therapy , Executive Function/drug effects , Propylamines/therapeutic use , Atomoxetine Hydrochloride , Attention Deficit Disorder with Hyperactivity/complications , Attention Deficit Disorder with Hyperactivity/psychology , Child , Cross-Over Studies , Dose-Response Relationship, Drug , Dyslexia/complications , Dyslexia/psychology , Humans , Inhibition, Psychological , Memory/drug effects , Neuropsychological Tests , Reading , Treatment OutcomeABSTRACT
Individuals with Autism Spectrum Disorder (ASD) are characterised by an impaired imitation, thought to be critical for early affective, social and communicative development. One neurological system proposed to underlie this function is the mirror neuron system (MNS) and previous research has suggested a dysfunctional MNS in ASD. The EEG mu frequency, more precisely the reduction of the mu power, is considered to be an index for mirror neuron functioning. In this work, EEG registrations are used to evaluate the mirror neuron functioning of twenty children with high functioning autism (HFA) between 8 and 13 years. Their mu suppression to self-executed and observed movement is compared to typically developing peers and related to age, intelligence and symptom severity. Both groups show significant mu suppression to both self and observed hand movements. No group differences are found in either condition. These results do not support the hypothesis that HFA is associated with a dysfunctional MNS. The discrepancy with previous research is discussed in light of the heterogeneity of the ASD population.
Subject(s)
Autistic Disorder/physiopathology , Brain/physiopathology , Motor Activity/physiology , Neurons/physiology , Visual Perception/physiology , Adolescent , Analysis of Variance , Child , Child Development/physiology , Electroencephalography , Female , Hand , Humans , Intelligence/physiology , Male , Neuropsychological Tests , Photic Stimulation , Severity of Illness IndexABSTRACT
The nature of the comorbidity between Attention-Deficit/Hyperactivity Disorder (ADHD) and Reading Disability (RD) was examined using a double dissociation design. Children were between 8 and 12 years of age and entered into four groups: ADHD only (n = 24), ADHD+RD (n = 29), RD only (n = 41) and normal controls (n = 26). In total, 120 children participated in the study; 38 girls and 82 boys. Both ADHD and RD were associated with impairments in inhibition and lexical decision, although inhibition and lexical decision were more severely impaired in RD than in ADHD. Visuospatial working memory deficits were specific to children with only ADHD. It is concluded that there was overlap on lexical decision and to a lesser extent on inhibition between ADHD and RD. In ADHD, impairments were dependent on IQ, which suggest that the overlap in lexical decision and inhibition is different in origin for ADHD and RD. The ADHD only group was specifically characterized by deficits in visuospatial working memory. Hence, no double dissociation between ADHD and RD was found on executive functioning and lexical decision.
Subject(s)
Attention Deficit Disorder with Hyperactivity/psychology , Dyslexia/psychology , Age Factors , Attention Deficit Disorder with Hyperactivity/complications , Attention Deficit Disorder with Hyperactivity/diagnosis , Child , Dyslexia/complications , Dyslexia/diagnosis , Female , Humans , Intelligence , Male , Memory , Neuropsychological Tests , Psychiatric Status Rating Scales , Regression AnalysisABSTRACT
The current study compared high-functioning children with autism (HFA) and a peer control group on an immediate arousal task measuring response inhibition. In one condition go stimuli were presented whereas in another condition a tone preceded the go stimulus. The tone caused an immediate arousal effect, which resulted in a reaction time decrease and an error rate increase. It was expected that children with HFA would produce a higher error rate in comparison with normal peers, since they might be less able to suppress immediate arousal. However, the HFA group outperformed the control group, indicating neither arousal regulation deficit nor response inhibition deficit.
Subject(s)
Arousal/physiology , Autistic Disorder/psychology , Inhibition, Psychological , Reaction Time/physiology , Adolescent , Analysis of Variance , Child , Female , Humans , Male , Peer Group , Psychomotor Performance , Reference Values , Task Performance and Analysis , Time FactorsABSTRACT
The aim of the current study was to evaluate arousal modulation and response inhibition in adults with high functioning autism (HFA). Using a go/no-go paradigm with varying presentation rate, it was found that performance efficiency (Mean RT, Standard Deviation of RT and Errors of Commission) in adults with HFA was the same as in the control group in the condition with a slow (6 s) and medium (2 s) presentation rate, but that it decreased in the condition with a fast presentation rate (1 s): many errors of commission were made in this condition. Findings were interpreted in terms of an arousal modulation deficiency that interfered with the capacity to inhibit responses in HFA.
