118 research outputs found
Mathematics anxiety in children with developmental dyscalculia
<p>Abstract</p> <p>Background</p> <p>Math anxiety, defined as a negative affective response to mathematics, is known to have deleterious effects on math performance in the general population. However, the assumption that math anxiety is directly related to math performance, has not yet been validated. Thus, our primary objective was to investigate the effects of math anxiety on numerical processing in children with specific deficits in the acquisition of math skills (Developmental Dyscalculia; DD) by using a novel affective priming task as an indirect measure.</p> <p>Methods</p> <p>Participants (12 children with DD and 11 typically-developing peers) completed a novel priming task in which an arithmetic equation was preceded by one of four types of priming words (positive, neutral, negative or related to mathematics). Children were required to indicate whether the equation (simple math facts based on addition, subtraction, multiplication or division) was true or false. Typically, people respond to target stimuli more quickly after presentation of an affectively-related prime than after one that is unrelated affectively.</p> <p>Result</p> <p>Participants with DD responded faster to targets that were preceded by both negative primes and math-related primes. A reversed pattern was present in the control group.</p> <p>Conclusion</p> <p>These results reveal a direct link between emotions, arithmetic and low achievement in math. It is also suggested that arithmetic-affective priming might be used as an indirect measure of math anxiety.</p
Working memory and inattentive behaviour in a community sample of children
BACKGROUND: Existing literature to date suggests a relationship between cognitive attention and working memory (WM), but the relationship between overt inattentive behaviour and WM is less clear. This study examined the relationship between WM and parent-rated inattentive behaviour in a community sample of 140 children aged 7–12 years. METHODS: Children completed 2 clinical (laboratory-based) measures of WM (auditory-verbal and visual-spatial) and a measure of real-life WM, designed specifically for this study, while their parents completed questionnaires about their child's inattentive behaviour and other areas of functioning. RESULTS: Findings indicated that poorer performance on WM tasks predicted inattentive behaviour. CONCLUSION: These results are consistent with previous research linking WM deficits and poor attention in ADHD and normal populations. The present findings support a controlled attention model of WM
Visual function and color vision in adults with Attention-Deficit/Hyperactivity Disorder
AbstractPurposeColor vision and self-reported visual function in everyday life in young adults with Attention-Deficit/Hyperactivity Disorder (ADHD) were investigated.MethodParticipants were 30 young adults with ADHD and 30 controls matched for age and gender. They were tested individually and completed the Visual Activities Questionnaire (VAQ), Farnsworth-Munsell 100 Hue Test (FMT) and A Quick Test of Cognitive Speed (AQT).ResultsThe ADHD group reported significantly more problems in 4 of 8 areas on the VAQ: depth perception, peripheral vision, visual search and visual processing speed. Further analyses of VAQ items revealed that the ADHD group endorsed more visual problems associated with driving than controls. Color perception difficulties on the FMT were restricted to the blue spectrum in the ADHD group. FMT and AQT results revealed slower processing of visual stimuli in the ADHD group.ConclusionA comprehensive investigation of mechanisms underlying visual function and color vision in adults with ADHD is warranted, along with the potential impact of these visual problems on driving performance
Cognition in Anxious Children with Attention Deficit Hyperactivity Disorder: A Comparison with Clinical and Normal Children
Background: Cognition in children with anxiety disorders (ANX) and comorbid Attention DeficitDisorder (ADHD) has received little attention, potentially impacting clinical and academicinterventions in this highly disabled group. This study examined several cognitive features relativeto children with either pure condition and to normal controls.Methods: One hundred and eight children ages 8–12 and parents were diagnosed by semistructuredparent interview and teacher report as having: ANX (any anxiety disorder except OCDor PTSD; n = 52), ADHD (n = 21), or ANX + ADHD (n = 35). All completed measures of academicability, emotional perception, and working memory. Clinical subjects were compared to 35 normalcontrols from local schools.Results: Groups did not differ significantly on age, gender, or estimated IQ. On analyses ofvariance, groups differed on academic functioning (Wide Range Achievement Test, p < .001),perception of emotion (auditory perception of anger, p < .05), and working memory (backwardsdigits, p < .01; backwards finger windows, p < .05; Chipasat task, p < .001). ANX + ADHD andchildren with ADHD did poorly relative to controls on all differentiating measures except auditoryperception of anger, where ANX + ADHD showed less sensitivity than children with ANX or withADHD.Conclusion: Though requiring replication, findings suggest that ANX + ADHD relates to greatercognitive and academic vulnerability than ANX, but may relate to reduced perception of anger
Executive and motivational processes in adolescents with Attention-Deficit-Hyperactivity Disorder (ADHD)
BACKGROUND: The objective of the current study was to examine performance and correlates of performance on a decision-making card task involving risky choices (Iowa Gambling Task) in adolescents with ADHD and comparison controls. Forty-four participants with ADHD and 34 controls were administered measures of estimated intellectual ability, working memory, and the card task. Also, behavioural ratings were obtained from parents and teachers. RESULTS: Adolescents with ADHD scored lower on the measures of intellectual ability, working memory, and made less advantageous selections on the card task compared to controls. Performance on measures of intellectual ability and working memory were unrelated to card task performance in both the ADHD and control samples. Parent ratings of hyperactivity/impulsivity were significantly associated with card task performance in the adolescents with ADHD, but not in controls. CONCLUSION: These findings demonstrate impaired decision-making in adolescents with ADHD, and the separability of motivational and executive function processes, supporting current dual pathway models of ADHD
Prosocial skills may be necessary for better peer functioning in children with symptoms of disruptive behavior disorders
Children with disruptive behavior disorders experience substantial social challenges; however, the factors that account for (i.e., mediate), or influence (i.e., moderate), peer problems are not well understood. This study tested whether symptoms of Oppositional Defiant Disorder and Conduct Disorder were associated with peer impairment and whether prosocial skills mediated or moderated these associations. Teacher ratings were gathered for 149 children (Mage = 9.09, SD = 1.71, 26% female) referred for behavioral concerns to an urban child psychiatry clinic. Path-analytic linear regressions testing mediation and moderation effects showed that prosocial skills significantly moderated the negative effects of symptoms of Conduct Disorder on peer impairment. Children showed less peer impairment only when they had relatively few conduct symptoms and high prosocial skills. Measurement of prosocial skills, in addition to conduct problems, may best capture factors which contribute to peer problems of children with disruptive behaviors
MEG event-related desynchronization and synchronization deficits during basic somatosensory processing in individuals with ADHD
<p>Abstract</p> <p>Background</p> <p>Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent, complex disorder which is characterized by symptoms of inattention, hyperactivity, and impulsivity. Convergent evidence from neurobiological studies of ADHD identifies dysfunction in fronto-striatal-cerebellar circuitry as the source of behavioural deficits. Recent studies have shown that regions governing basic sensory processing, such as the somatosensory cortex, show abnormalities in those with ADHD suggesting that these processes may also be compromised.</p> <p>Methods</p> <p>We used event-related magnetoencephalography (MEG) to examine patterns of cortical rhythms in the primary (SI) and secondary (SII) somatosensory cortices in response to median nerve stimulation, in 9 adults with ADHD and 10 healthy controls. Stimuli were brief (0.2 ms) non-painful electrical pulses presented to the median nerve in two counterbalanced conditions: unpredictable and predictable stimulus presentation. We measured changes in strength, synchronicity, and frequency of cortical rhythms.</p> <p>Results</p> <p>Healthy comparison group showed strong event-related desynchrony and synchrony in SI and SII. By contrast, those with ADHD showed significantly weaker event-related desynchrony and event-related synchrony in the alpha (8–12 Hz) and beta (15–30 Hz) bands, respectively. This was most striking during random presentation of median nerve stimulation. Adults with ADHD showed significantly shorter duration of beta rebound in both SI and SII except for when the onset of the stimulus event could be predicted. In this case, the rhythmicity of SI (but not SII) in the ADHD group did not differ from that of controls.</p> <p>Conclusion</p> <p>Our findings suggest that somatosensory processing is altered in individuals with ADHD. MEG constitutes a promising approach to profiling patterns of neural activity during the processing of sensory input (e.g., detection of a tactile stimulus, stimulus predictability) and facilitating our understanding of how basic sensory processing may underlie and/or be influenced by more complex neural networks involved in higher order processing.</p
Resting state EEG oscillatory power differences in ADHD college students and their peers
Response variability in Attention-Deficit/Hyperactivity Disorder: a neuronal and glial energetics hypothesis
BACKGROUND: Current concepts of Attention-Deficit/Hyperactivity Disorder (ADHD) emphasize the role of higher-order cognitive functions and reinforcement processes attributed to structural and biochemical anomalies in cortical and limbic neural networks innervated by the monoamines, dopamine, noradrenaline and serotonin. However, these explanations do not account for the ubiquitous findings in ADHD of intra-individual performance variability, particularly on tasks that require continual responses to rapid, externally-paced stimuli. Nor do they consider attention as a temporal process dependent upon a continuous energy supply for efficient and consistent function. A consideration of this feature of intra-individual response variability, which is not unique to ADHD but is also found in other disorders, leads to a new perspective on the causes and potential remedies of specific aspects of ADHD. THE HYPOTHESIS: We propose that in ADHD, astrocyte function is insufficient, particularly in terms of its formation and supply of lactate. This insufficiency has implications both for performance and development: H1) In rapidly firing neurons there is deficient ATP production, slow restoration of ionic gradients across neuronal membranes and delayed neuronal firing; H2) In oligodendrocytes insufficient lactate supply impairs fatty acid synthesis and myelination of axons during development. These effects occur over vastly different time scales: those due to deficient ATP (H1) occur over milliseconds, whereas those due to deficient myelination (H2) occur over months and years. Collectively the neural outcomes of impaired astrocytic release of lactate manifest behaviourally as inefficient and inconsistent performance (variable response times across the lifespan, especially during activities that require sustained speeded responses and complex information processing). TESTING THE HYPOTHESIS: Multi-level and multi-method approaches are required. These include: 1) Use of dynamic strategies to evaluate cognitive performance under conditions that vary in duration, complexity, speed, and reinforcement; 2) Use of sensitive neuroimaging techniques such as diffusion tensor imaging, magnetic resonance spectroscopy, electroencephalography or magnetoencephalopathy to quantify developmental changes in myelination in ADHD as a potential basis for the delayed maturation of brain function and coordination, and 3) Investigation of the prevalence of genetic markers for factors that regulate energy metabolism (lactate, glutamate, glucose transporters, glycogen synthase, glycogen phosphorylase, glycolytic enzymes), release of glutamate from synaptic terminals and glutamate-stimulated lactate production (SNAP25, glutamate receptors, adenosine receptors, neurexins, intracellular Ca(2+)), as well as astrocyte function (α(1), α(2 )and β-adrenoceptors, dopamine D1 receptors) and myelin synthesis (lactate transporter, Lingo-1, Quaking homolog, leukemia inhibitory factor, and Transferrin). IMPLICATIONS OF THE HYPOTHESIS: The hypothesis extends existing theories of ADHD by proposing a physiological basis for specific aspects of the ADHD phenotype – namely frequent, transient and impairing fluctuations in functioning, particularly during performance of speeded, effortful tasks. The immediate effects of deficient ATP production and slow restoration of ionic gradients across membranes of rapidly firing neurons have implications for daily functioning: For individuals with ADHD, performance efficacy would be enhanced if repetitive and lengthy effortful tasks were segmented to reduce concurrent demands for speed and accuracy of response (introduction of breaks into lengthy/effortful activities such as examinations, motorway driving, assembly-line production). Also, variations in task or modality and the use of self- rather than system-paced schedules would be helpful. This would enable energetic demands to be distributed to alternate neural resources, and energy reserves to be re-established. Longer-term effects may manifest as reduction in regional brain volumes since brain areas with the highest energy demand will be most affected by a restricted energy supply and may be reduced in size. Novel forms of therapeutic agent and delivery system could be based on factors that regulate energy production and myelin synthesis. Since the phenomena and our proposed basis for it are not unique to ADHD but also manifests in other disorders, the implications of our hypotheses may be relevant to understanding and remediating these other conditions as well
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