Memory In Boys Research Articles

Single-dose effects of methylphenidate and atomoxetine on functional connectivity during an n-back task in boys with ADHD

RationaleWorking memory deficits and associated neurofunctional abnormalities are frequently reported in attention-deficit/hyperactivity disorder (ADHD). Methylphenidate and atomoxetine improve working memory performance and increase activation of regions under-functioning in ADHD. Additionally, methylphenidate has been observed to modulate functional networks involved in working memory. No research, however, has examined the effects of atomoxetine or compared the two drugs.ObjectivesThis study aimed to test methylphenidate and atomoxetine effects on functional connectivity during working memory in boys with ADHD.MethodsWe tested comparative effects of methylphenidate and atomoxetine on functional connectivity during the n-back task in 19 medication-naïve boys with ADHD (10–15 years old) relative to placebo and assessed potential normalisation effects of brain dysfunctions under placebo relative to 20 age-matched neurotypical boys. Patients were scanned in a randomised, double-blind, cross-over design under single doses of methylphenidate, atomoxetine, and placebo. Controls were scanned once, unmedicated.ResultsPatients under placebo showed abnormally increased connectivity between right superior parietal gyrus (rSPG) and left central operculum/insula. This hyperconnectivity was not observed when patients were under methylphenidate or atomoxetine. Furthermore, under methylphenidate, patients showed increased connectivity relative to controls between right middle frontal gyrus (rMFG) and cingulo-temporo-parietal and striato-thalamic regions, and between rSPG and cingulo-parietal areas. Interrogating these networks within patients revealed increased connectivity between both rMFG and rSPG and right supramarginal gyrus under methylphenidate relative to placebo. Nonetheless, no differences across drug conditions were observed within patients at whole brain level. No drug effects on performance were observed.ConclusionsThis study shows shared modulating effects of methylphenidate and atomoxetine on parieto-insular connectivity but exclusive effects of methylphenidate on connectivity increases in fronto-temporo-parietal and fronto-striato-thalamic networks in ADHD.

Association between the Use of Folic Acid Supplements during Pregnancy and Children's Cognitive Function at 7-9 Years of Age in the INMA Cohort Study.

This study investigated the association between maternal low (<400 μg/day) or high (≥1000 μg/day) folic acid supplements (FAs) use during pregnancy and the attentional function and working memory in boys and girls at age 7–9. A longitudinal analysis based on 1609 mother–child pairs from the Spanish Infancia y Medio Ambiente Project was carried out. Multivariable regression analyses revealed that, compared to the recommended FAs use, a low FAs use during the second period of pregnancy was associated with a lower alertness in all children (β = 18.70 ms; 95% CI: 7.51; 29.89) and in girls (β = 30.01 ms; 95% CI: 12.96; 47.01), and with a lower N-back Task performance in boys (d’ number 2-back (β = −0.25; 95% CI: −0.49; 0.01)). A high FAs use throughout the two periods of pregnancy was associated with a better N-back Task performance only in girls (d’ number 2-back (β = 0.28; 95% CI: 0.01; 0.56) and d’ number 3-back (β = 0.32; 95% CI: 0.08; 0.56)). The maternal use of FAs beyond the periconceptional period may affect children’s attentional function and working memory at age 7–9 differently for boys and girls.

Associations of Prenatal Urinary Bisphenol A Concentrations with Child Behaviors and Cognitive Abilities.

Background:Prenatal bisphenol A (BPA) exposure has been associated with adverse neurodevelopment in epidemiological studies. However, prior studies had limited statistical power to examine sex-specific effects, and few examined child cognition.Objectives:We estimated the association between prenatal BPA exposure and child neurobehavior at 3 y of age in a prospective cohort of 812 mothers and their children.Methods:We measured BPA concentration in urine samples collected at wk gestation among women enrolled in a 10-city Canadian cohort study. At approximately 3 y of age, we assessed children’s cognitive abilities with the Wechsler Primary and Preschool Scale of (WPPSI-III) and two scales of the Behavior Rating Inventory of Executive Function–Preschool (BRIEF-P). Parents reported children’s behavior using the Behavior Assessment System for Children–2 (BASC-2) and the Social Responsiveness Scale™ – 2. (SRS-2). We estimated covariate-adjusted differences in neurobehavioral outcomes with a doubling in BPA concentration and sex-specific associations.Results:BPA was not associated with WPPSI-III scores; child sex did not modify these associations. The association between BPA and BRIEF-P scores was modified by child sex (). For example, a doubling of BPA concentration was associated with 1-point (95% CI: 0.3, 1.7) poorer working memory in boys and 0.5-point (95% CI: , 0.1) better scores in girls. BPA was not associated with most BASC-2 scales; however, it was associated with more internalizing and somatizing behaviors in boys, but not in girls ( ). A doubling of BPA concentration was associated with poorer SRS-2 scores [ ( 95% CI: 0, 0.7)]; this association was not modified by sex.Conclusion:Prenatal urinary BPA concentration was associated with some aspects of child behavior in this cohort, and some associations were stronger among boys. https://doi.org/10.1289/EHP984

HPA axis function predicts development of working memory in boys with FXS

The present study examines verbal working memory over time in boys with fragile X syndrome (FXS) compared to nonverbal mental-age (NVMA) matched, typically developing (TD) boys. Concomitantly, the relationship between cortisol—a physiological marker for stress—and verbal working memory performance over time is examined to understand the role of physiological mechanisms in cognitive development in FXS. Participants were assessed between one and three times over a 2-year time frame using two verbal working memory tests that differ in complexity: memory for words and auditory working memory with salivary cortisol collected at the beginning and end of each assessment. Multilevel modeling results indicate specific deficits over time on the memory for words task in boys with FXS compared to TD controls that is exacerbated by elevated baseline cortisol. Similar increasing rates of growth over time were observed for boys with FXS and TD controls on the more complex auditory working memory task, but only boys with FXS displayed an association of increased baseline cortisol and lower performance. This study highlights the benefit of investigations of how dynamic biological and cognitive factors interact and influence cognitive development over time.

HPA axis function predicts development of working memory in boys with FXS

HPA axis function predicts development of working memory in boys with FXS

Association between Serum Copper Status and Working Memory in Schoolchildren.

Trace elements such as copper are essential micronutrients. Traditionally, copper has been studied in the context of micronutrient deficiencies. Recent studies in both animals and humans, however, have revealed that elevated blood copper can also have adverse effects on cognitive function since free copper can cross the blood-brain barrier and subsequently impose oxidative stress to neuronal cells. However, most of these human studies were conducted in adult populations with and without cognitive decline, and there are few studies on the effect of excess copper on cognitive function in children. This project seeks to look at the effects of elevated copper levels on cognitive development in a population of school age children (ages 10–14 years with mean age of 12.03 years and standard deviation (SD) of 0.44) from Jintan, China. Briefly, serum copper levels and working memory test scores were collected from a sample of 826 children with a mean serum copper level of 98.10 (SD 0.75). Copper level was considered as a categorical variable (taking the first group as those with as ≤84.3 μg/dL, the second group as >84.3 and ≤110.4 μg/dL, and the third group as >110.4 μg/dL with the cut-off values defined by the first and third quartiles of the sample). Results showed a significant association between high copper levels (>110.4 μg/dL) and poorer working memory in boys but this association was not seen in lower copper levels in either sex. These results suggests that in school age children, like in adults, elevated copper levels have the potential to adversely affect cognition.

Acetylcholinesterase Activity and Neurodevelopment in Boys and Girls

Organophosphate exposures can affect children's neurodevelopment, possibly due to neurotoxicity induced by acetylcholinesterase (AChE) inhibition, and may affect boys more than girls. We tested the hypothesis that lower AChE activity is associated with lower neurobehavioral development among children living in Ecuadorian floricultural communities. In 2008, we examined 307 children (age: 4-9 years; 52% male) and quantified AChE activity and neurodevelopment in 5 domains: attention/executive functioning, language, memory/learning, visuospatial processing, and sensorimotor (NEPSY-II test). Associations were adjusted for demographic and socioeconomic characteristics and height-for-age, flower worker cohabitation, and hemoglobin concentration. Mean ± standard deviation AChE activity was 3.14 ± 0.49 U/mL (similar for both genders). The range of scores among neurodevelopment subtests was 5.9 to 10.7 U (standard deviation: 2.6-4.9 U). Girls had a greater mean attention/executive functioning domain score than boys. In boys only, there were increased odds ratios of low (<9th percentile) neurodevelopment among those in the lowest tertile versus the highest tertile of AChE activity (odds ratios: total neurodevelopment: 5.14 [95% confidence interval (CI): 0.84 to 31.48]; attention/executive functioning domain: 4.55 [95% CI: 1.19 to 17.38], memory/learning domain: 6.03 [95% CI: 1.17 to 31.05]) after adjustment for socioeconomic and demographic factors, height-for-age, and hemoglobin. Within these domains, attention, inhibition and long-term memory subtests were most affected. Low AChE activity was associated with deficits in neurodevelopment, particularly in attention, inhibition, and memory in boys but not in girls. These critical cognitive skills affect learning and academic performance. Added precautions regarding secondary occupational pesticide exposure would be prudent.

Understanding Phonological Memory Deficits in Boys with Attention-Deficit/Hyperactivity Disorder (ADHD): Dissociation of Short-term Storage and Articulatory Rehearsal Processes

The current study dissociated and examined the two primary components of the phonological working memory subsystem--the short-term store and articulatory rehearsal mechanism--in boys with ADHD (n = 18) relative to typically developing boys (n = 15). Word lists of increasing length (2, 4, and 6 words per trial) were presented to and recalled by children following a brief (3 s) interval to assess their phonological short-term storage capacity. Children's ability to utilize the articulatory rehearsal mechanism to actively maintain information in the phonological short-term store was assessed using word lists at their established memory span but with extended rehearsal times (12 s and 21 s delays). Results indicate that both phonological shortterm storage capacity and articulatory rehearsal are impaired or underdeveloped to a significant extent in boys with ADHD relative to typically developing boys, even after controlling for age, SES, IQ, and reading speed. Larger magnitude deficits, however, were apparent in short-term storage capacity (ES = 1.15 to 1.98) relative to articulatory rehearsal (ES = 0.47 to 1.02). These findings are consistent with previous reports of deficient phonological short-term memory in boys with ADHD, and suggest that future attempts to develop remedial cognitive interventions for children with ADHD will need to include active components that require children to hold increasingly more information over longer time intervals.

Editorial: Identifying the cognitive and physiological underpinning of child psychiatric conditions

The February issue11 Articles in this issue (with italicised names below) can be found at: http://onlinelibrary.wiley.com/doi/10.1111/jcpp.2011.53.issue-2/issuetoc. represents several important approaches and domains found in contemporary psychology and psychiatry. First, several studies examined the links between child cognition and child outcomes. These studies are important because they attempt to move beyond broad diagnostic categories to a deeper understanding of their cognitive underpinnings. Shoemaker and colleagues examined the relationship between inhibition and working memory in preschool children with attention-deficit hyperactivity disorder (ADHD), disruptive behavioral disorder (DBD) and ADHD + DBD. The results of their study suggested that, as expected, children with ADHD showed significant inhibition deficits. Interestingly, children with DBD showed inhibition deficits, especially in situations with motivational incentives. Romens and Pollak examined the relationship between child maltreatment, depression, and attention bias. Results indicated that maltreated children displayed increased attention for depression-related stimuli, especially when provided with depression-related cues. The results of this study also suggested that children who ruminated demonstrated heightened and stable patterns of attention to depression-related cues. Rhodes and colleagues conducted a systematic analysis of memory in boys with ADHD and oppositional defiant disorder (ODD). These researchers asserted that combined ADHD+ODD constitutes comorbidity between two distinct conditions, as opposed to different expressions of the same underlying etiology. As noted in their commentary, Jarrold and Hall raised several important issues concerning limitations of the Rhodes et al. study. These were, in turn, addressed by a response by Coghill and Rhodes. The reader is encouraged to consider Rhodes et al., Jarrold & Hall., and Coghill & Rhodes in their totality. Additionally, the current issue presents several papers addressing issues related to autism spectrum disorders (ASD). Kim and Lord examined the combined use of the Autism Diagnostic Interview-Revise (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS). Their study suggested that these measures tap additive dimensions of ASD, which leads to more stable and accurate diagnoses. Peters and colleagues examined autism-related features and behaviors in children with Angelman syndrome. This study is important because it examined this issue in children with chromosomal deletions. In particular, children with Class I deletions were more likely to show greater impairments in social affect and more repetitive behaviors than children with Class II deletions. These characteristics also appeared to persist longitudinally. Geluk and colleagues examined the longitudinal association between autistic symptoms and delinquent behavior in childhood arrestees, finding that autistic symptoms are more prevalent in these children compared to the unselected population. This study raises important questions concerning the interpretation of behavior as related to autism or related to delinquency in this population of children. Finally, a set of papers in this issue addressed the relationship between behavioral measures, physiological measures, and complex child outcomes. First, Wetter and El-Sheikh examined growth trajectories on internalizing symptoms in children, as predicted by maternal internalizing behavior and children’s basal respiratory sinus arrhythmia (RSA), which is a measure of parasympathetic nervous system functioning. Results suggested that child physiological measures predict a portion of the substantial individual differences in children with familial risk for psychopathology. Kossowsky and colleagues suggested that separation from mother led to greater sympathetic nervous responsivity in children with separation anxiety disorder compared to controls. Murray and colleagues suggested that anxious mothers are no different from non-anxious mothers under typical conditions. However, mothers with anxiety disorders show difficulties when placed under stress. Tan and colleagues examined emotional reactivity and regulation in anxious versus nonanxious children using a cell phone-based study. What was most interesting about this study, aside from the ecological validity of the design, was the finding that, similar to the Murray et al. study, persons at risk for anxiety demonstrated difficulties in response to challenging events, but appeared to be no different from controls in other conditions. Finally, Kujawa and colleagues studied electrocortical reactivity to emotional faces in young children, and their relationship with parental depression. Children of mothers with a history of depression were more likely to show reduced physiological responses for faces with emotional content, suggesting that this response may be a biomarker for (as opposed to a consequence of) depression. Taken together, the studies contained in this issue demonstrate that child psychology and psychiatry are beginning to systematically integrate cognitive and physiological measures into theory. This is important, not only because of increased explanation of the substantial heterogeneity found in most diagnostic categories, but also because of the potential for developing cognitive or physiological biomarkers that can be employed to better identify, treat, or prevent childhood disorders.

Working memory subsystems and task complexity in young boys with Fragile X syndrome: Working memory in boys with FXS

Working memory subsystems and task complexity in young boys with Fragile X syndrome: Working memory in boys with FXS