Error processing in high-functioning Autism Spectrum Disorders

Studies report error-processing abnormalities in high-functioning individuals with Autism Spectrum Disorders (ASD) that may be influenced by intelligence and autism severity. Error processing can be measured using the error-related negativity (ERN) and post-error positivity (Pe) components of the event-related potential (ERP), along with behavioral indices such as post-error reaction time (RT) slowing. We used a modified Flanker task to test the hypothesis that high-functioning individuals with ASD would show decreased amplitude ERN in 24 individuals with ASD and 21 age- and IQ-matched typically-developing control participants. Behaviorally, individuals with ASD committed more errors than controls, but groups did not significantly differ on RTs, although there was a trend-level difference in post-error slowing. For ERPs, ERN amplitude was significantly attenuated in individuals with ASD relative to controls; groups did not differ in Pe amplitude. Amplitude of the ERN was not significantly correlated with measures of intelligence, anxiety, behavioral inhibition, or general autism severity.     

Idiom Comprehension Deficits in High-Functioning Autism Spectrum Disorder Using a Korean Autism Social Language Task

Purpose

High-functioning autism spectrum disorder (ASD) involves pragmatic impairment of language skills. Among numerous tasks for assessing pragmatic linguistic skills, idioms are important to evaluating high-functioning ASD. Nevertheless, no assessment tool has been developed with specific consideration of Korean culture. Therefore, we designed the Korean Autism Social Language Task (KASLAT) to test idiom comprehension in ASD. The aim of the current study was to introduce this novel psychological tool and evaluate idiom comprehension deficits in high-functioning ASD.

Materials and Methods

The participants included 42 children, ages 6-11 years, who visited our child psychiatric clinic between April 2014 and May 2015. The ASD group comprised 16 children; the attention deficit hyperactivity disorder (ADHD) group consisted of 16 children. An additional 10 normal control children who had not been diagnosed with either disorder participated in this study. Idiom comprehension ability was assessed in these three groups using the KASLAT.

Results

Both ASD and ADHD groups had significantly lower scores on the matched and mismatched tasks, compared to the normal control children (matched tasks mean score: ASD 11.56, ADHD 11.56, normal control 14.30; mismatched tasks mean score: ASD 6.50, ADHD 4.31, normal control 11.30). However, no significant differences were found in scores of KASLAT between the ADHD and ASD groups.

Conclusion

These findings suggest that children with ASD exhibit greater impairment in idiom comprehension, compared to normal control children. The KASLAT may be useful in evaluating idiom comprehension ability.     

The Integrated Visual and Auditory Continuous Performance Test as a neuropsychological measure.

The Integrated Visual and Auditory (IVA) Continuous Performance Test (CPT) and Neuropsychological Impairment Scale (NIS) were completed by adults diagnosed with mild traumatic brain injury (mTBI), adults diagnosed with attention deficit hyperactivity disorder (ADHD), and controls. On the IVA CPT, the mTBI and ADHD groups performed significantly lower on the full and secondary scales for attention and response accuracy. For individual scales, the mTBI and ADHD groups showed lower performance on measures of reaction time, inattention, impulsivity, and variability of RT. The mTBI and ADHD groups showed similar patterns of performance on the IVA. On the NIS, the mTBI and ADHD groups reported more neuropsychological symptoms than the control group, and the mTBI group reported more neuropsychological symptoms than the ADHD group. The results are discussed in regard to changes in cognitive processing and sustained attention in individuals diagnosed with mTBI and ADHD.     

The intermediate visual and auditory continuous performance test as a neuropsychological measure.

The Intermediate Visual and Auditory (IVA) Continuous Performance Test (CPT) and Neuropsychological Impairment Scale (NIS) were completed with adults diagnosed with mild traumatic brain injury (mTBI), adults diagnosed with Attention Deficit Hyperactivity Disorder (ADHD), and controls. On the IVACPT, the mTBI and ADHD groups performed significantly lower on the full and secondary scales for attention and response accuracy. For individual scales, the mTBI and ADHD groups showed lower performance on measures of reaction time, inattention, impulsivity, and variability of RT. The mTBI and ADHD groups showed similar patterns of performance on the IVA. On the NIS, the mTBI and ADHD groups reported more neuropsychological symptoms than the control group and the mTBI group reported more neuropsychological symptoms than the ADHD group. The results are discussed in regard to changes in cognitive processing and sustained attention in individuals diagnosed with mTBI and ADHD.     

Reaction time variability in children with ADHD symptoms and/or dyslexia

Reaction time (RT) variability on a Stop Signal task was examined among children with attention deficit hyperactivity disorder (ADHD) symptoms and/or dyslexia in comparison to typically developing (TD) controls. Children's go-trial RTs were analyzed using a novel ex-Gaussian method. Children with ADHD symptoms had increased variability in the fast but not the slow portions of their RT distributions compared to those without ADHD symptoms. The RT distributions of children with dyslexia were similar to those of TD-controls. It is argued that variability in responding may be underpinned by impairments in response preparation or timing during Stop Signal tasks.     

Reaction Time Variability in Children With ADHD Symptoms and/or Dyslexia

Reaction time (RT) variability on a Stop Signal task was examined among children with attention deficit hyperactivity disorder (ADHD) symptoms and/or dyslexia in comparison to typically developing (TD) controls. Children's go-trial RTs were analyzed using a novel ex-Gaussian method. Children with ADHD symptoms had increased variability in the fast but not the slow portions of their RT distributions compared to those without ADHD symptoms. The RT distributions of children with dyslexia were similar to those of TD-controls. It is argued that variability in responding may be underpinned by impairments in response preparation or timing during Stop Signal tasks.     

Time Reproduction Deficits at Young Adult Follow-Up in Childhood ADHD: The Role of Persistence of Disorder and Executive Functioning

No studies have examined if time reproduction deficits exist in children with attention deficit hyperactivity disorder (ADHD) by adulthood. We followed 131 ADHD and 71 community control (CC) cases for 20+ years to young adulthood at which time they were given a time reproduction task. The ADHD group made smaller time reproductions and showed greater variability of errors at the longer durations compared to CC cases, whether ADHD was still present or not at follow-up. Nonverbal working memory and design fluency tests were related to timing errors while anxiety and depression were not. Childhood ADHD is associated with timing deficits at adult follow-up.     

Can bipolar disorder-specific neuropsychological impairments in children be identified?

This study examined neuropsychological deficits among children with bipolar disorder while attending to its comorbidity with attention-deficit/hyperactivity disorder (ADHD). Seventy-three unmedicated children (ages 6-17 years) with Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) bipolar disorder plus ADHD (BPD + ADHD) were compared with 102 unmedicated children with ADHD without bipolar disorder, and 120 children without bipolar disorder or ADHD. Ninety-four percent of participants were Caucasian, 58% were male, and 42% were female. On average participants were of middle to upper socioeconomic status. Participants were assessed with a comprehensive neuropsychological battery and measures of academic achievement, school failure, and special education placement. Participants with BPD + ADHD and with ADHD were impaired in interference control, verbal learning, and arithmetic achievement and had higher rates of special school services. Across all of the measures of neuropsychological functioning, the only difference observed between youths with BPD + ADHD and youths with ADHD was that youths with BPD + ADHD performed more poorly on one measure of processing speed. Thus, comorbidity with ADHD may account for many of the neuropsychological deficits observed in children with bipolar disorder.     

Reaction time performance in ADHD: improvement under fast-incentive condition and familial effects

BACKGROUND: Reaction time (RT) variability is one of the strongest findings to emerge in cognitive-experimental research of attention deficit hyperactivity disorder (ADHD). We set out to confirm the association between ADHD and slow and variable RTs and investigate the degree to which RT performance improves under fast event rate and incentives. Using a group familial correlation approach, we tested the hypothesis that there are shared familial effects on RT performance and ADHD. METHOD: A total of 144 ADHD combined-type probands, 125 siblings of the ADHD probands and 60 control participants, ages 6-18, performed a four-choice RT task with baseline and fast-incentive conditions. RESULTS: ADHD was associated with slow and variable RTs, and with greater improvement in speed and RT variability from baseline to fast-incentive condition. RT performance showed shared familial influences with ADHD. Under the assumption that the familial effects represent genetic influences, the proportion of the phenotypic correlation due to shared familial influences was estimated as 60-70%. CONCLUSIONS: The data are inconsistent with models that consider RT variability as reflecting a stable cognitive deficit in ADHD, but instead emphasize the extent to which energetic or motivational factors can have a greater effect on RT performance in ADHD. The findings support the role of RT variability as an endophenotype mediating the link between genes and ADHD.     

Executive functioning in hyperactive children as young adults: attention, inhibition, response perseveration, and the impact of comorbidity

Tests of several executive functions (EFs) as well as direct observations of symptoms of attention deficit hyperactivity disorder (ADHD) during testing were collected at the young adult follow-up (M = 20 years) on a large sample of hyperactive (H; N = 147) and community control (CC; N = 71) children. The EF tasks included tests of attention, inhibition, and response perseveration. The H group was subdivided into those with and without ADHD (+ or w/o) at follow-up. The H+ADHD group made significantly more inhibition errors than the CC group on a Continuous Performance Test (CPT) and showed more ADHD symptoms while performing the CPT. The H+ADHD group also displayed more ADHD symptoms during a letter cancellation task than did both the hyperactive w/o ADHD and CC groups. Both H groups showed slower reaction times during a Card Playing Task. That subset of hyperactive probands with Conduct Disorder (CD) displayed significantly more perseverative responding on that task than did those without CD, but otherwise it did not differ on any other measures. Current level of anxiety contributed adversely to both CPT commission errors and ADHD behavior during the CPT. Comorbid depression did not contribute to any group differences on these tests. Although developmental improvements were found in both the H and the CC groups in their CPT inattention and inhibition scores since adolescence, the H groups remained distinguishable from the CC groups over this period. We conclude that formerly hyperactive children manifest greater EF deficits at follow-up in the areas of inattention, disinhibition, and slowed reaction time and greater ADHD behavior during testing, but these problems are mostly confined to those with current ADHD. Response perseveration, however, was limited to those hyperactive children with CD by follow-up, consistent with Quay's theory of these two disorders.     

Executive Functioning in Hyperactive Children as Young Adults: Attention,Inhibition, Response Perseveration,and the Impact of Comorbidity

Tests of several executive functions (EFs) as well as direct observations of symptoms of attention deficit hyperactivity disorder (ADHD) during testing were collected at the young adult follow-up (M = 20 years) on a large sample of hyperactive (H; N = 147) and community control (CC; N = 71) children. The EF tasks included tests of attention, inhibition, and response perseveration. The H group was subdivided into those with and without ADHD (+ or w/o) at follow-up. The H+ADHD group made significantly more inhibition errors than the CC group on a Continuous Performance Test (CPT) and showed more ADHD symptoms while performing the CPT. The H+ADHD group also displayed more ADHD symptoms during a letter cancellation task than did both the hyperactive w/o ADHD and CC groups. Both H groups showed slower reaction times during a Card Playing Task. That subset of hyperactive probands with Conduct Disorder (CD) displayed significantly more perseverative responding on that task than did those without CD, but otherwise it did not differ on any other measures. Current level of anxiety contributed adversely to both CPT commission errors and ADHD behavior during the CPT. Comorbid depression did not contribute to any group differences on these tests. Although developmental improvements were found in both the H and the CC groups in their CPT inattention and inhibition scores since adolescence, the H groups remained distinguishable from the CC groups over this period. We conclude that formerly hyperactive children manifest greater EF deficits at follow-up in the areas of inattention, disinhibition, and slowed reaction time and greater ADHD behavior during testing, but these problems are mostly confined to those with current ADHD. Response perseveration, however, was limited to those hyperactive children with CD by follow-up, consistent with Quay's theory of these two disorders.     

Does parental ADHD bias maternal reports of ADHD symptoms in children?

Within families, co-occurring attention-deficit/hyperactivity disorder (ADHD) in parents and children may be common. The authors evaluated the hypothesis that parental ADHD may lead to a reporting bias of ADHD symptoms in offspring. They combined 2 family case-controlled studies of ADHD using structured interviews. They compared rates of maternal reported ADHD symptoms among 3 groups of ADHD children: no parental ADHD (n = 231), mother with ADHD (n = 63), and father with ADHD (n = 57). With the exception of 1 symptom, the rates of reporting between groups did not differ. There was no evidence that the discrepancy between maternal reports and self-reports of symptoms differed by parental ADHD. Results were similar across child gender or referral status. These results do not support the notion that parental ADHD affects maternal reports of offspring ADHD.     

The effects of childhood disruptive disorder comorbidity on P3 event-related brain potentials in preadolescents with ADHD

The present study examined the degree to which the P300 component of the visual brain event-related potential and associated task performance deficits often observed in children with attention-deficit hyperactivity disorder (ADHD) are attributable to comorbid childhood disruptive disorders using a community sample of 11-year olds from the Minnesota Twin Family Study. Subjects were divided into "ADHD-pure" (ADHD without oppositional defiant disorder, ODD, or conduct disorder, CD), "ADHD-comorbid" (ADHD with ODD or CD), and comparison (no childhood disruptive disorder) groups using DSM-III-R diagnoses. Results showed that ADHD-comorbid but not ADHD-pure subjects displayed significant P3 amplitude reduction and poorer task performance compared to controls. No group effects for P3 latency or reaction time were seen. Although ADHD-comorbid children had marginally more ADHD symptoms compared to ADHD-pure children, this did not account for their reduced P3, suggesting that the observed neurobehavioral deficits reflected the effects of co-occurring childhood disruptive disorders.     

Neurocognitive Functioning Mediates the Prospective Association of Birth Weight With Youth ADHD Symptoms

Although birth weight is a potential causal risk factor for attention-deficit/hyperactivity disorder (ADHD) symptoms, both the specificity of this association and its mediating pathways are largely unknown. We carefully assessed youth with and without ADHD (i.e., Wave 1), and followed them prospectively for 2 years (i.e., Wave 2). We (a) tested the association of birth weight with Wave 2 ADHD symptoms, and (b) evaluated biologically plausible neurocognitive functions from Wave 1 as temporally ordered mediators of birth weight and Wave 2 ADHD symptoms in a multiple mediation framework. At Wave 1, 222 ethnically diverse youth (30% female; ages 5–10) completed the Digit Span, Vocabulary, Symbol Search, and Arithmetic subtests of the Wechsler Intelligence Scale for Children–IV. At both Wave 1 and Wave 2 (ages 7–13), multiple informants (i.e., parents, teachers) rated youth ADHD symptoms and co-occurring psychopathology using multiple methods (i.e., structured interview, rating scale). Controlling for demographic factors, gestational age, and co-occurring externalizing and internalizing psychopathology, birth weight inversely predicted Wave 2 ADHD symptoms across multiple methods and informants. Additionally, controlling for Wave 1 ADHD symptoms and relevant covariates, Wave 1 Arithmetic uniquely mediated the association of birth weight with multi-method/informant Wave 2 ADHD symptoms. These findings suggest that birth weight is a relatively specific risk factor for youth ADHD symptoms and they implicate individual differences in fluid reasoning as a preliminary causal mediator of this association. We discuss implications for future research evaluating causal mechanisms underlying risk factors for ADHD.     

Shared and Disorder-Specific Event-Related Brain Oscillatory Markers of Attentional Dysfunction in ADHD and Bipolar Disorder

Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) often present with overlapping symptoms and cognitive impairments, such as increased fluctuations in attentional performance measured by increased reaction-time variability (RTV). We previously provided initial evidence of shared and distinct event-related potential (ERP) impairments in ADHD and BD in a direct electrophysiological comparison, but no study to date has compared neural mechanisms underlying attentional impairments with finer-grained brain oscillatory markers. Here, we aimed to compare the neural underpinnings of impaired attentional processes in ADHD and BD, by examining event-related brain oscillations during a reaction-time task under slow-unrewarded baseline and fast-incentive conditions. We measured cognitive performance, ERPs and brain-oscillatory modulations of power and phase variability in 20 women with ADHD, 20 women with BD (currently euthymic) and 20 control women. Compared to controls, both ADHD and BD groups showed increased RTV in the baseline condition and increased RTV, theta phase variability and lower contingent negative variation in the fast-incentive condition. Unlike controls, neither clinical group showed an improvement from the slow-unrewarded baseline to the fast-incentive condition in attentional P3 amplitude or alpha power suppression. Most impairments did not differ between the disorders, as only an adjustment in beta suppression between conditions (lower in the ADHD group) distinguished between the clinical groups. These findings suggest shared impairments in women with ADHD and BD in cognitive and neural variability, preparatory activity and inability to adjust attention allocation and activation. These overlapping impairments may represent shared neurobiological mechanisms of attentional dysfunction in ADHD and BD, and potentially underlie common symptoms in both disorders.     

Inhibitory processes in adults with persistent childhood onset ADHD

The theory that attention-deficit/hyperactivity disorder (ADHD) stems from a deficit in an executive behavioral inhibition process has been little studied in adults, where the validity of ADHD is in debate. This study examined, in high-functioning young adults with persistent ADHD and a control group, 2 leading measures of inhibitory control: the antisaccad task and the negative priming task. ADHD adults showed weakened ability to effortfully stop a refle ve or anticipated oculomotor response but had normal ability to automatically suppress irrelevant information. Results suggest that an inhibitory deficit in ADHD is confined to effortful inhibition of motor response, that antisaccade and negative priming tasks index distinct inhibition systems, and that persistence of ADHD symptoms into adulthood is associated with persistence of executive motor inhibition deficits.     

Reaction time variability in ADHD: A meta-analytic review of 319 studies

Individuals with ADHD are characterized as ubiquitously slower and more variable than their unaffected peers, and increased reaction time (RT) variability is considered by many to reflect an etiologically important characteristic of ADHD. The present review critically evaluates these claims through meta-analysis of 319 studies of RT variability in children, adolescents, and adults with ADHD relative to typically developing (TD) groups, clinical control groups, and themselves (subtype comparisons, treatment and motivation effects). Random effects models corrected for measurement unreliability and publication bias revealed that children/adolescents (Hedges' g = 0.76) and adults (g = 0.46) with ADHD demonstrated greater RT variability relative to TD groups. This increased variability was attenuated by psychostimulant treatment (g = − 0.74), but unaffected by non-stimulant medical and psychosocial interventions. Individuals with ADHD did not evince slower processing speed (mean RT) after accounting for RT variability, whereas large magnitude RT variability deficits remained after accounting for mean RT. Adolescents and adults with ADHD were indistinguishable from clinical control groups, and children with ADHD were only minimally more variable than clinical control children (g = 0.25). Collectively, results of the meta-analysis indicate that RT variability reflects a stable feature of ADHD and other clinical disorders that is robust to systematic differences across studies.     

Variability of Response Time as a Predictor of Methylphenidate Treatment Response in Korean Children with Attention Deficit Hyperactivity Disorder

Purpose

Methylphenidate (MPH) is an effective medication for the treatment of attention deficit hyperactivity disorder (ADHD). However, about 30% of patients do not respond to or are unable to tolerate MPH. Based on previous findings, we hypothesized that great variability in response time (RT) among Korean children with ADHD on a computerized continuous performance attention test would be related to poor MPH treatment response.

Materials and Methods

Children (ages 6-18 years) with ADHD were recruited for a prospective 12-week, open-labeled, multicenter study to examine optimal dosage of OROS methylphenidate. Of the 144 subjects selected, 28 dropped out due to adverse events, medication noncompliance, or follow-up loss, and an additional 26 subjects with comorbid disorders were excluded from statistical analyses. We defined ''responders'' as subjects who received a score of less than 18 on the attention deficit hyperactivity disorder rating scale (ARS; Korean version, K-ARS) and a score of 1 or 2 on the Clinical Global Impression-Improvement scale (CGI-I). RT variability was assessed with the ADHD diagnostic system (ADS).

Results

Fifty-nine (67%) subjects responded to MPH treatment. The non-responders showed greater RT variability at baseline (Mann Whitney U = 577.0, p < 0.01). Baseline RT variability was a significant predictor of MPH response (Nagelkerke R² = 0.136, p < 0.01). It predicted 94.9% of responder, 17.2% of non-responder and 69.3% of overall group.

Conclusion

High RT variability may predict poor response to MPH treatment in children with ADHD.     

Differentiating major depressive disorder in youths with attention deficit hyperactivity disorder

BACKGROUND: Youths with attention deficit hyperactivity disorders (ADHD) frequently have comorbid major depressive disorders (MDD) sharing overlapping symptoms. Our objective was to examine which depressive symptoms best discriminate MDD among youths with ADHD. METHODS: One-hundred-eleven youths with ADHD (5.2-17.8 years old) and their parents completed interviews with the K-SADS-PL and respective versions of the child or the parent Mood and Feelings Questionnaire (MFQ-C, MFQ-P). Controlling for group differences, logistic regression was used to calculate odds ratios reflecting the accuracy with which various depressive symptoms on the MFQ-C or MFQ-P discriminated MDD. Stepwise logistic regression then identified depressive symptoms that best discriminated the groups with and without MDD, using cross-validated misclassification rate as the criterion. RESULTS: Symptoms that discriminated youths with MDD (n=18) from those without MDD (n=93) were 4 of 6 mood/anhedonia symptoms, all 14 depressed cognition symptoms, and only 3 of 11 physical/vegetative symptoms. Mild irritability, miserable/unhappy moods, and symptoms related to sleep, appetite, energy levels and concentration did not discriminate MDD. A stepwise logistic regression correctly classified 89% of the comorbid MDD subjects, with only age, anhedonia at school, thoughts about killing self, thoughts that bad things would happen, and talking more slowly remaining in the final model. LIMITATIONS: Results of this study may not generalize to community samples because subjects were drawn largely from a university-based outpatient psychiatric clinic. CONCLUSIONS: These findings stress the importance of social withdrawal, anhedonia, depressive cognitions, suicidal thoughts, and psychomotor retardation when trying to identify MDD among ADHD youths.     

Temporal Reward Discounting in Children with Attention Deficit/Hyperactivity Disorder (ADHD), and Children with Autism Spectrum Disorder (ASD): A Systematic Review

ABSTRACT

Children with ADHD and ASD may present differences in the affective-motivational processes. We systematically review the literature regarding temporal discounting in children up to 12 years with ADHD and ASD. Six articles were included, five studies with ADHD children (n = 231), one with ASD children (n = 21), all including typically developing children as controls (n = 210). Five studies (four with ADHD and one with ASD) found greater temporal reward discounting for clinical groups. Occurrence of ADHD appears to rush even more the decision-making process at this stage of development, but there is still a lack in the literature, especially evaluating individuals with ASD.