Visual sustained attention in a child psychiatric population

Pupillometry as a Window into Young Children's Sustained Attention

Sustained attention is critical to cognition, social competence, and academic success. Importantly, sustained attention undergoes significant development over the early childhood period. Yet, how sustained attention fluctuates over time on task has not been clearly outlined, particularly in young children. In this study, we provide a first test of whether the pupillary response can be used as an indicator of moment-to-moment sustained attention over time on task in young children. Children aged 5 to 7 years (N = 41) completed a psychomotor vigilance task, where they were asked to press a button as fast as possible at the onset of a target stimulus. We measured reaction times over the course of the task, pupil size prior to target onset (baseline pupil size), and pupil size in response to target onset (task-evoked pupil size). The results showed a stereotypical vigilance decrement in children's response times: as time on task increased, reaction times increased. Critically, children's task-evoked pupil size decreased over time on task, while no such change was present in baseline pupil size. These results suggest that young children's waning sustained attention may be linked to a decrease in alertness while overall arousal is maintained. We discuss the importance of leveraging pupillometry to understand the mechanisms of sustained attention over individuals and development.

Developmental Changes of Autistic Symptoms, ADHD Symptoms, and Attentional Performance in Children and Adolescents with Autism Spectrum Disorder

This study followed up ADHD/autistic symptoms and attentional performance in children/adolescents with ASD and typically developing ones (TD) over 5-7 years. The participants were stratified by age at baseline into child (< 12 years) and adolescent (12-19 years) groups. ADHD symptoms, especially hyperactivity, and attentional functions significantly improved during follow-up, more in children than in adolescents, in both ASD and TD. Significantly more omission errors and perseverations were noted in ASD than TD through the follow-up. Children with ASD had more improvement in reaction time while adolescents with ASD had less improvement in commission errors and detectability than TD. No correlation of attentional functions and ADHD symptoms in ASD implied different neural mechanisms of ADHD symptoms between ASD and ADHD.

Attentional Processes in Children With Attentional Problems or Reading Difficulties as Revealed Using Brain Event-Related Potentials and Their Source Localization

Visual attention-related processes include three functional sub-processes: alerting, orienting, and inhibition. We examined these sub-processes using reaction times, event-related potentials (ERPs), and their neuronal source activations during the Attention Network Test (ANT) in control children, attentional problems (AP) children, and reading difficulties (RD) children. During the ANT, electroencephalography was measured using 128 electrodes on three groups of Finnish sixth-graders aged 12–13 years (control = 77; AP = 15; RD = 23). Participants were asked to detect the direction of a middle target fish within a group of five fish. The target stimulus was either preceded by a cue (center, double, or spatial), or without a cue, to manipulate the alerting and orienting sub-processes of attention. The direction of the target fish was either congruent or incongruent in relation to the flanker fish, thereby manipulating the inhibition sub-processes of attention. Reaction time performance showed no differences between groups in alerting, orienting, and inhibition effects. The group differences in ERPs were only found at the source level. Neuronal source analysis in the AP children revealed a larger alerting effect (double-cued vs. non-cued target stimuli) than control and RD children in the left occipital lobe. Control children showed a smaller orienting effect (spatially cued vs. center-cued target stimuli) in the left occipital lobe than AP and RD children. No group differences were found for the neuronal sources related to the inhibition effect. The neuronal activity differences related to sub-processes of attention in the AP and RD groups suggest different underlying mechanisms for attentional and reading problems.

Shared endo-phenotypes of default mode dsfunction in attention deficit/hyperactivity disorder and autism spectrum disorder

Categorical diagnoses from the Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD) manuals are increasingly found to be incongruent with emerging neuroscientific evidence that points towards shared neurobiological dysfunction underlying attention deficit/hyperactivity disorder and autism spectrum disorder. Using resting-state functional magnetic resonance imaging data, functional connectivity of the default mode network, the dorsal attention and salience network was studied in 1305 typically developing and diagnosed participants. A transdiagnostic hierarchical Bayesian modeling framework combining Indian Buffet Processes and Latent Dirichlet Allocation was proposed to address the urgent need for objective brain-derived measures that can acknowledge shared brain network dysfunction in both disorders. We identified three main variation factors characterized by distinct coupling patterns of the temporoparietal cortices in the default mode network with the dorsal attention and salience network. The brain-derived factors were demonstrated to effectively capture the underlying neural dysfunction shared in both disorders more accurately, and to enable more reliable diagnoses of neurobiological dysfunction. The brain-derived phenotypes alone allowed for a classification accuracy reflecting an underlying neuropathology of 67.33% (+/-3.07) in new individuals, which significantly outperformed the 46.73% (+/-3.97) accuracy of categorical diagnoses. Our results provide initial evidence that shared neural dysfunction in ADHD and ASD can be derived from conventional brain recordings in a data-led fashion. Our work is encouraging to pursue a translational endeavor to find and further study brain-derived phenotypes, which could potentially be used to improve clinical decision-making and optimize treatment in the future.

Neuropsychological Consequences for Survivors of Childhood Brain Tumor in Malaysia

Objective: This study aimed to evaluate neuropsychological consequences in survivors of childhood brain tumor.

Method: A case-control study was conducted over a period of 4 months in a tertiary referral center in Kuala Lumpur, Malaysia. Fourteen survivors of childhood brain tumor aged 7–18 years, who were off-treatment for at least 1 year and were in remission, and 31 unrelated healthy controls were recruited. The median age at diagnosis was 8.20 years (range: 0.92–12.96 years). The diagnoses of brain tumors were medulloblastoma, germ cell tumor, pineocytoma, pilocystic astrocytoma, suprasellar germinoma, and ependymoma. Eleven survivors received central nervous system irradiation. Seven tasks were selected from the Amsterdam Neuropsychological Tasks program to evaluate alertness (processing speed), and major aspects of executive functioning, such as working memory capacity, inhibition, cognitive flexibility, and sustained attention. Speed, stability and accuracy of responses were the main outcome measures.

Results: Survivors of childhood brain tumor showed statistically significant poorer performance on all tasks compared to healthy controls. Both processing speed and accuracy were impaired in the survivors, in particular under more complex task conditions. The survivors demonstrated deficits in alertness, sustained attention, working memory capacity, executive visuomotor control, and cognitive flexibility. Longer duration off treatment appeared to be correlated with poorer alertness, memory capacity, and inhibition.

Conclusion: Survivors of childhood brain tumor in our center showed impaired neuropsychological functioning. Development of less toxic treatment protocols is important to prevent late effects of cognitive deficits in survivors of childhood brain tumor.

Behavioral and Neural Sustained Attention Deficits in Disruptive Mood Dysregulation Disorder and Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Disruptive mood dysregulation disorder (DMDD), characterized by severe irritability, and attention-deficit/hyperactivity disorder (ADHD) are highly comorbid. This is the first study to characterize neural and behavioral similarities and differences in attentional functioning across these disorders.

METHOD

Twenty-seven healthy volunteers, 31 patients with DMDD, and 25 patients with ADHD (8 to 18 years old) completed a functional magnetic resonance imaging attention task. Group differences in intra-subject variability in reaction time (RT) were examined. The present functional magnetic resonance imaging analytic approach precisely quantified trial-wise associations between RT and brain activity.

RESULTS

Group differences manifested in the relation between RT and brain activity (all regions: p < .01, F > 2.54, partial eta-squared [ηp2] > 0.06). Patients with DMDD showed specific alterations in the right paracentral lobule, superior parietal lobule, fusiform gyrus, and cerebellar culmen. In contrast, patients with DMDD and those with ADHD exhibited blunted compensatory increases in activity on long RT trials. In addition, youth with DMDD exhibited increased activity in the postcentral gyrus, medial frontal gyrus, and cerebellar tonsil and declive (all regions: p < .05, F > 2.46, ηp2 > 0.06). Groups in the imaging sample did not differ significantly in intra-subject variability in RT (F2,79 = 2.664, p = .076, ηp2 = 0.063), although intra-subject variability in RT was significantly increased in youth with DMDD and ADHD when including those not meeting strict motion and accuracy criteria for imaging analysis (F2,96 = 4.283, p = .017, ηp2 = 0.083).

CONCLUSION

Patients with DMDD exhibited specific alterations in the relation between pre-stimulus brain activity and RT. Patients with DMDD and those with ADHD exhibited similar blunting of compensatory neural activity in frontal, parietal, and other regions. In addition, patients with DMDD showed increased RT variability compared with healthy youth. This work is the first to identify common and unique behavioral and neural signatures of DMDD and ADHD.

Diminished Infant P50 Sensory Gating Predicts Increased 40-Month-Old Attention, Anxiety/Depression, and Externalizing Symptoms

OBJECTIVE

When behavioral problems resulting from attentional difficulties present, often in preschool, it is unknown whether these problems represent preexisting altered brain development or new brain changes. This study examines whether infant sensory gating of auditory evoked potentials predicts parent-reported behavior at 40 months.

METHOD

P50 sensory gating, an auditory evoked potential measure reflective of inhibitory processes in the brain, was measured in 50 infants around 70 days old. Parents, using the Child Behavior Checklist, reported on the child's behavior at 40 months.

RESULTS

Controlling for gender, infants with diminished sensory gating had more problems later with externalizing behavior ( F = 4.17, ndf = 1, ddf = 46, p = .047), attentional problems ( F = 5.23, ndf = 1, ddf = 46, p = .027), and anxious/depressed symptoms ( F = 5.36, ndf = 1, ddf = 46, p = .025).

CONCLUSION

Diminished infant P50 sensory gating predicts attention symptoms 3 years later. These results support the hypothesis that preschool attentional dysfunction may relate to altered brain development that is detectable years prior to symptom onset.

Time-on-task effects in children with and without ADHD: depletion of executive resources or depletion of motivation?

Children with attention-deficit/hyperactivity disorder (ADHD) are characterized by deficits in their executive functioning and motivation. In addition, these children are characterized by a decline in performance as time-on-task increases (i.e., time-on-task effects). However, it is unknown whether these time-on-task effects should be attributed to deficits in executive functioning or to deficits in motivation. Some studies in typically developing (TD) adults indicated that time-on-task effects should be interpreted as depletion of executive resources, but other studies suggested that they represent depletion of motivation. We, therefore, investigated, in children with and without ADHD, whether there were time-on-task effects on executive functions, such as inhibition and (in)attention, and whether these were best explained by depletion of executive resources or depletion of motivation. The stop-signal task (SST), which generates both indices of inhibition (stop-signal reaction time) and attention (reaction time variability and errors), was administered in 96 children (42 ADHD, 54 TD controls; aged 9-13). To differentiate between depletion of resources and depletion of motivation, the SST was administered twice. Half of the participants was reinforced during second task performance, potentially counteracting depletion of motivation. Multilevel analyses indicated that children with ADHD were more affected by time-on-task than controls on two measures of inattention, but not on inhibition. In the ADHD group, reinforcement only improved performance on one index of attention (i.e., reaction time variability). The current findings suggest that time-on-task effects in children with ADHD occur specifically in the attentional domain, and seem to originate in both depletion of executive resources and depletion of motivation. Clinical implications for diagnostics, psycho-education, and intervention are discussed.

Neurocognitive Phenotypes in Severe Childhood Psychiatric Disorders

This study investigated the presence of potential neurocognitive phenotypes within a severe childhood psychiatric sample. A medical chart review was conducted for 106 children who received a neuropsychological evaluation during children's psychiatric inpatient program hospitalization. A hierarchical cluster analysis was conducted to identify distinct clinical clusters based on neurocognitive measures. Cluster analysis identified four distinct clusters, subsequently labeled neurocognitive phenotypes: "intact cognition" (27%), "global dysfunction" (20%), "organization/planning" (21%), and "inhibition-memory" (32%). Significant differences were identified in history of legal involvement and antipsychotic medications at hospital admission. Differences between none-minimal and moderate-high neurocognitive dysfunction were identified in age, amount of diagnoses and antipsychotic medications at admission, and hospital length of stay. Current findings provide preliminary evidence of underlying neurocognitive phenotypes within severe childhood psychiatric disorders. Findings highlight the importance of neuropsychological evaluation in the treatment of childhood psychiatric disorders.

Animal-Assisted Interventions for Children with Attention Deficit/Hyperactivity Disorder: A Theoretical Review and Consideration of Future Research Directions

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prevalent neurodevelopmental disorders and is characterized by core symptoms of inattention, impulsivity, and hyperactivity. Given the limitations of the existing treatment strategies, it seems necessary to consider the further exploration of alternative treatment approaches. In this review, the application and complementary use of animal-assisted interventions to the treatment of ADHD were discussed. Several mechanisms including calming, socializing, motivating, and cognitive effects of animal-assisted interventions were explored. Since studies directly investigating these effects on ADHD are scarce, so each of them were examined in terms of how it could benefit the treatment of ADHD. These effects can have a positive effect on several core symptoms of ADHD.

The DiViSA's Predictive Validity by Age: An Objective Online Test of Attention

The purpose of this study was to analyze the DiViSA's predictive validity in school-age children. To do so, two groups of school-age children were compared: one with low school achievement (N = 1,174), and one with typical development (N = 1,426). The obtained results show that: (1) in all grades, children with poor school performance exhibited lower levels of attention and task organization, greater hastiness, and made more commission errors; (2) the combination of variables that best differentiated between groups was not the same in all grades; (3) level of organization improved with age in the low-school-achievement group, and did not in the typical-development group; (4) the data regarding sensitivity (81% to 93%) and specificity (79% to 90%), for the first time computed for each grade separately, support the test's predictive validity in the grades we evaluated. The discussion focuses on the DiViSA test's usefulness in diagnosing attention problems. It is the first computerized test to include separate scores for: (a) how children complete the task (organization) and (2) the source of their errors (distraction or hastiness).

Reaction Time and Attention: Toward a New Standard in the Assessment of ADHD? A Pilot Study

This pilot study shows results of an experiment comparing reaction times (RTs) and attentional performance between an ADHD group of 30 children and 30 controls, both Spanish speaking. The experiment was carried out using the Seville computerized neuropsychological battery (SNB).

OBJECTIVE

This study had two goals: One was to test sensitivity of SNB for attention deficits in ADHD and the second was to detect differences in RTs between ADHD and controls. Possible explanations and implications of such differences are also discussed.

METHOD

SNB computerized system was used to assess RTs and accuracy, and alternate forms of continuous performance task were used.

RESULTS

Results showed high sensitivity of some of the SNB tests, especially cancellation tests. RTs were significantly different between groups.

CONCLUSION

SNB represents a helpful tool for detection of attention deficits, and RT indices represent the most significant variable in differentiation of both groups studied.

Anxiety Disorders Comorbidity in Children and Adolescents with Attention Deficit Hyperactivity Disorder

INTRODUCTION

Our aim is to investigate the prevalence of comorbidity of anxiety disorders (AD) among patients newly diagnosed with attention deficit hyperactivity disorder (ADHD) and to compare symptom severity of ADHD and sociodemographic parameters between patients with and without AD.

METHODS

Among 1683 children and adolescents admitted to Kocaeli University Medical Faculty, Child and Adolescent Mental Health Outpatient Clinic, 447 children and adolescents, who were preliminarily diagnosed as ADHD by clinical interview based on Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), were invited to participate in the second phase of the study. Kiddie Schedule for Affective Disorder and Schizophrenia, Present and Lifetime-Turkish Version were applied to children and adolescents with ADHD and one of their parents to support the diagnoses of both ADHD and AD. Mothers, fathers, and teachers of the children were asked to complete DSM-IV-Based Child and Adolescent Behavior Disorders Screening and Rating Scale.

RESULTS

Our study group comprised 170 children and adolescents diagnosed with ADHD of whom 19.4% were girls and 80.6% were boys; 27.6% of patients diagnosed with ADHD showed AD comorbidity. Age of the parents at birth of the patients with AD was significantly lower than that of patients without AD.

CONCLUSION

In line with the previous studies, the comorbidity rate of AD was found to be higher among patients with ADHD than general population and clinical sample without ADHD. The possibility of comorbidity of AD in patients with ADHD should be considered because higher rates of AD are observed in ADHD and comorbidities of AD.

Annual research review: Infant development, autism, and ADHD--early pathways to emerging disorders

BACKGROUND

Autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD) are two of the most common neurodevelopmental disorders, with a high degree of co-occurrence.

METHODS

Prospective longitudinal studies of infants who later meet criteria for ASD or ADHD offer the opportunity to determine whether the two disorders share developmental pathways.

RESULTS

Prospective studies of younger siblings of children with autism have revealed a range of infant behavioral and neural markers associated with later diagnosis of ASD. Research on infants with later ADHD is less developed, but emerging evidence reveals a number of relations between infant measures and later symptoms of inattention and hyperactivity.

CONCLUSIONS

We review this literature, highlighting points of convergence and divergence in the early pathways to ASD and ADHD.

Cortical thickness and inattention/hyperactivity symptoms in young children: a population-based study

BACKGROUND

While many neuroimaging studies have investigated the neurobiological basis of attention deficit hyperactivity disorder (ADHD), few have studied the neurobiology of attention problems in the general population. The ability to pay attention falls along a continuum within the population, with children with ADHD at one extreme of the spectrum and, therefore, a dimensional perspective of evaluating attention problems has an added value to the existing literature. Our goal was to investigate the relationship between cortical thickness and inattention and hyperactivity symptoms in a large population of young children.

METHOD

This study is embedded within the Generation R Study and includes 6- to 8-year-old children (n = 444) with parent-reported attention and hyperactivity measures and high-resolution structural imaging data. We investigated the relationship between cortical thickness across the entire brain and the Child Behavior Checklist Attention Deficit Hyperactivity Problems score.

RESULTS

We found that greater attention problems and hyperactivity were associated with a thinner right and left postcentral gyrus. When correcting for potential confounding factors and multiple testing, these associations remained significant.

CONCLUSIONS

In a large, population-based sample we showed that young (6- to 8-year-old) children who show more attention problems and hyperactivity have a thinner cortex in the region of the right and left postcentral gyrus. The postcentral gyrus, being the primary somatosensory cortex, reaches its peak growth early in development. Therefore, the thinner cortex in this region may reflect either a deviation in cortical maturation or a failure to reach the same peak cortical thickness compared with children without attention or hyperactivity problems.

Executive function in MCDD and PDD-NOS: a study of inhibitory control, attention regulation and behavioral adaptivity

A proportion of children within the autism spectrum is at risk for severe deregulation of thought, emotion and behaviour resulting in (symptoms of) psychotic disorders over the course of development. In an attempt to identify this subgroup, children with PDD-NOS, subtype MCDD (n = 24) were compared to children with PDD-NOS (n = 23) on executive function (EF) skills. Significant differences emerged, always to the disadvantage of the children with PDD-NOS, subtype MCDD on various EF measures. The findings suggest compromised attention regulation and impaired inhibitory control in children with MCDD, which may help explain high levels of thought problems which are frequently observed in these children. Our findings provide evidence for recognizing a PDD subcategory of MCDD that is of specific interest with regard to long-term developmental risks involved.

The effect of different stimulus attributes on the attentional performance of children with attention deficit/hyperactivity disorder and dyslexia

While teachers have traditionally used the interesting objects to increase student attention in the classroom, evidence supporting the effectiveness of this method is lacking. The present study investigated the influence of different stimulus attributes for typical developing students and for students with attention deficit/hyperactivity disorder (ADHD) and dyslexia. Thirty children with ADHD, 30 children with dyslexia, and 30 typical developing students were tested using a measuring tool that was constructed by the authors to assess their sustained attention and selective attention on the geometric-figure assessment and the interesting-figure assessment. The geometric-figure assessment included a square, circle, trapezium, and triangle; and the interesting-figure assessment included a house, cat, hand, and tree. While the typical developing group showed better selective attention on the geometric-figure assessment, there was no difference between the dyslexic group and the ADHD group with respect to selective attention. Furthermore, the typical developing and dyslexic groups did not differ in the geometric-figure assessment in sustained attention and were both better in this area than the ADHD group. In the interesting-figure assessment, the typical developing and dyslexic groups performed similarly in sustained attention, but selective attention of the dyslexic group improved more than the ADHD group, similar to the typical developing group. Both selective attention of the dyslexic group and sustained attention of the ADHD group showed positive significant differences in the interesting-figure assessment, but sustained attention of the dyslexic group and selective attention of the ADHD group showed little difference in the interesting-figure assessment. Surprisingly, the typical developing group did not show any significant difference in the interesting-figure assessment, possibly because they had previously demonstrated a ceiling effect in the geometric-figure assessment.

Psychometric Properties of a Test for ADHD Based on Binocular Rivalry

The psychometric properties of a Binocular Rivalry (BR)-based test on a group of 159 participants (57 with attention deficit hyperactivity disorder, ADHD) aged between 6 and 15 years are presented. Two factors, which explained 56.82% of the variance, were obtained by exploratory factor analysis: (a) Alternations and Duration of exclusive dominances, and (b) Decision time. Reliability was excellent (Cronbach’s α = .834 and .884). The ADHD group showed fewer alternations and longer duration of dominances and decision time than the control group. Correlations between measures of BR, IQ, working memory, and processing speed of the WISC-IV, and ADHD symptoms, assessed by parents and teachers, ranged between low and medium.

Conners' continuous performance test (CCPT-II) in children with ADHD, ODD, or a combined ADHD/ODD diagnosis

The current study investigated if results on the Conners' Continuous Performance Test (CCPT-II) could discriminate between children with ADHD (n = 59), ODD (n = 10), ADHD+ODD (n = 15), and normal controls (n =160), and how the results are associated with and explained by the intellectual function of the child. The sample was derived from the Bergen Child Study (BCS), a longitudinal, ongoing, population-based study of children's development and mental health. CCPT-II performance did not differentiate between the three diagnostic groups (i.e., ADHD, ODD, and ADHD+ODD). Children with ODD (with or without comorbid ADHD) did not differ from children in the control group on any CCPT-II parameters. Children with ADHD made statistically significant more errors of omissions and showed a more variable response time to targets than the control group. The correlations between CCPT-II measures and IQ were mild to moderate, and there was a statistically significant group difference in IQ: Children with ADHD, and children with ADHD+ODD, obtained lower IQ scores than normal controls. A hierarchical multiple regression analysis showed that IQ, but not diagnostic group status, was significant predictors of CCPT-II performance. CCPT-II performance should be interpreted with caution when assessing ADHD and/or ODD in children.

A Review of Functioning of Attentional Components in Children With Attention-Deficit/Hyperactivity Disorder and Learning Disabilities

Attention is considered to be the foundation of most cognitive and neuropsychological processes and it is often the subject of study in the common childhood disorder, attention-deficit/hyperactivity disorder (ADHD). This article reviews studies on the attentional functioning of children with subtypes of ADHD and children with learning disabilities (LD). First, an overview of ADHD including current conceptualisation and cognitive theories of the disorder are outlined. Second, attention is described as a multidimensional construct consisting of a number of components. This model of attention will be used as a framework for reviewing studies in the ADHD literature. In particular, the following comparisons of children will be examined: (1) ADHD compared with non-disordered controls, (2) ADHD compared with LD, and (3) hyperactivity/impulsive forms of ADHD compared with inattentive ADHD. Finally, the implications of a multi-modal framework of attention will be discussed within the context of theory and treatment of ADHD.

Sustained Attention Development during the Toddlerhood to Preschool Period: Associations with Toddlers' Emotion Regulation Strategies and Maternal Behavior

The current study examined the role of maternal behavior and toddlers' emotion regulation strategies in the development of children's sustained attention abilities. Participants for this study included 447 children (232 girls) obtained from three different cohorts participating in a larger ongoing longitudinal study. When the children were 2 years of age, mothers brought their children to the laboratory and were videotaped during several tasks designed to elicit emotion regulation and mother- child interaction. Sustained attention was also measured at the same visit via a laboratory task and in a subsequent visit when children were 4.5 years of age. Results indicated that toddlers' use of help-seeking emotion regulation strategies was positively related to sustained attention while avoidance behaviors and maternal behavior characterized by high levels of overcontrolling/intrusiveness were negatively related to sustained attention at age 2. Significant interactions emerged such that high levels of maternal warmth/responsiveness buffered the negative associations between low use of distraction and high use of self-comforting emotion regulation strategies and sustained attention at age 2. Maternal behavior characterized by high levels of warmth/responsiveness also predicted greater growth in sustained attention from age 2 to 4.5. These findings are discussed in terms of how maternal behaviors and children's use of active versus passive emotion regulation strategies relate to sustained attention abilities.

Interference control in children with first episode major depression: a brief report

The ability to deal with sources of conflict, that is, interference control, was evaluated in a group of 11 children with first episode Major Depression and a peer control group. To this end, the Eriksen and Schultz (1979) task was used. Here, the participant is presented with a stimulus that simultaneously activates two conflicting response channels: One response is activated by the instructions, whereas the other response is activated by elements in the array that strongly invite an alternative - yet incorrect - response. Findings provided no evidence for an undisturbed interference control nor impaired overall processing speed in children with first episode Major Depression.

A systematic review of prospective studies on attention problems and academic achievement

OBJECTIVE

Our aim was to provide an overview of prospective studies that have addressed the association between attention problems (AP, i.e. symptoms of hyperactivity and inattentiveness) and academic achievement (AA).

METHOD

We conducted a systematic search in the literature. Normal population studies and clinical studies were included. The methodological quality of each study was evaluated by objective criteria. A best evidence synthesis was used to determine the strengths of the association.

RESULTS

Sixteen studies were included. We found convincing evidence for a negative association between AP and AA. After controlling for intelligence, comorbidity, and socioeconomic status (SES), the association between the hyperactive symptoms of AP and AA was non-significant in two studies.

CONCLUSION

Children with AP are at risk for lower AA and subsequent adverse outcomes later in life. Interventions in affected children should focus on their behavioural and educational development.

Effects of maternal and paternal smoking on attentional control in children with and without ADHD

Maternal smoking during pregnancy is a risk factor for attention-deficit/hyperactivity disorder (ADHD), but data on its adverse effects on cognitive functioning are sparse and inconsistent. Since the effect of maternal smoking during pregnancy may be due to correlated genetic risk factors rather than being a pure environmental effect, we examined the effect of prenatal exposure to smoking on attentional control, taking into account the effects of both maternal and paternal smoking, and examined whether these effects were genetically mediated by parental genotypes. We further examined whether the effect of prenatal exposure to smoking on attentional control interacted with genotypes of the child. Participants were 79 children with ADHD, ascertained for the International Multi-centre ADHD Gene project (IMAGE), and 105 normal controls. Attentional control was assessed by a visual continuous performance task. Three genetic risk factors for ADHD (DRD4 7-repeat allele of the exon 3 variable number of tandem repeats (VNTR), DAT1 10/10 genotype of the VNTR located in the 3' untranslated region, and the DAT1 6/6 genotype of the intron 8 VNTR) were included in the analyses. Paternal smoking had a negative effect on attentional control in children with ADHD and this effect appeared to be mediated by genetic risk factors. The prenatal smoking effect did not interact with genotypes of the child. Maternal smoking had no main effect on attentional control, which may be due to lower smoking rates. This study suggests that the effects of paternal smoking on attentional control in children with ADHD should be considered a proxy for ADHD and/or smoking risk genes. Future studies should examine if the results can be generalized to other cognitive domains.

Variability of attention processes in ADHD: observations from the classroom

OBJECTIVE

Classroom- and laboratory-based efforts to study the attentional problems of children with ADHD are incongruent in elucidating attentional deficits; however, none have explored within- or between-minute variability in the classroom attentional processing in children with ADHD.

METHOD

High and low attention groups of ADHD children defined via cluster analysis, and 36 typically developing children, were observed while completing academic assignments in their general education classrooms.

RESULTS

All children oscillated between attentive and inattentive states; however, children in both ADHD groups switched states more frequently and remained attentive for shorter durations relative to typically developing children.

CONCLUSION

Overall differences in attention and optimal ability to maintain attention among the groups are consistent with laboratory studies of increased ADHD-related interindividual and intergroup variability but inconsistent with laboratory results of increased intra-individual variability and attention decrements over time.

A new behavioral test for assessment of drug effects on attentional performance and its validity in cynomolgus monkeys

The assessment of drug effects on attention is important in non-clinical pharmacology, for both evaluation of safety and therapeutic efficacy of medicinal products. In the present study, we have developed a two-lever choice behavioral test to assess drug effects on attentional performance in monkeys. In each trial of this experiment, one of two lamps in front of a monkey was randomly illuminated for a brief period of time and the monkey was required to press a lever beneath the lamp 30 times to obtain a food reward. The percentage of correct responses, response latency of correct choice responses and response speed were measured. Using this test, we examined the effects of three sedative drugs, diazepam (0.25, 1 and 4 mg/kg, i.g.), ethanol (0.5, 1 and 2 g/kg, i.g.), and pentobarbital (0.25, 1 and 4 mg/kg, i.v.). Diazepam and pentobarbital lengthened response latency without significantly affecting the percentage of correct responses, response and response speed, suggesting selective disruptive effects on attentional performance. In contrast, ethanol at the high dose tested caused deterioration in all three measurements, which is thought to reflect a general sedative effect including motor impairment as reflected by lengthening response speed. It is suggested that the present behavioral test method could detect drug effects on attentional performance in monkeys and could be a useful tool for safety assessment in drug development.

Model comparison for automatic characterization and classification of average ERPs using visual oddball paradigm

OBJECTIVE

To determine whether automated classifiers can be used for correctly identifying target categorization responses from averaged event-related potentials (ERPs) along with identifying appropriate features and classification models for computer-assisted investigation of attentional processes.

METHODS

ERPs were recorded during a target categorization task. Automated classification of average target ERPs versus average non-target ERPs was performed by extracting different combinations of features from the P300 and N200 components, which were used to train six classifiers: Euclidean classifier (EC), Mahalanobis discriminant (MD), quadratic classifier (QC), Fisher linear discriminant (FLD), multi-layer perceptron neural network (MLP) and support vector machine (SVM).

RESULTS

The best classification performance (accuracy: 91-92%; sensitivity: 85-86%; specificity: 95-99%) was provided by QC, MLP, SVM on feature vectors extracted from P300 recorded at multiple sites. In general, non-linear and non-parametric classifiers (QC, MLP, SVM) performed better than linear classifiers (EC, MD, FLD). The N200 did not explain variance beyond that of P300 recorded at multiple sites.

CONCLUSIONS

The results suggest that automatic characterization and classification of average target and non-target ERPs is feasible. Features of P300 recorded at multiple sites used to train non-linear classifiers are recommended for optimal classification performance.

SIGNIFICANCE

Automatic characterization of target ERPs can provide an objective approach for detecting and diagnosing abnormalities and evaluating interventions for clinical populations, paving the way for future real-time monitoring of attentional processes.

Sustained and focused attention deficits in adult ADHD

OBJECTIVE

To examine the specificity of deficits in focused attention and sustained attention in adults with ADHD and to evaluate the effect of comorbidity.

METHOD

Twenty-eight adults with ADHD without comorbidity were compared with 28 ADHD outpatients with comorbidity. Two control groups were used: 68 adults referred for ADHD but with another psychopathology rather than ADHD (non-ADHD) and 28 healthy controls. All participants completed attention tests of the Amsterdam Neuropsychological Tasks program.

RESULTS

Both ADHD groups demonstrated a sustained attention deficit relative to the control groups, as indicated by a disproportionate deterioration of speed fluctuation with time-on-task reflecting temporal lapses in attention. Only the ADHD+ group showed focused attention deficits in that they were less able to ignore irrelevant information.

CONCLUSION

These findings show that adults with ADHD have specific deficits in sustained attention. Additional deficits in focused attention are confined to outpatients with ADHD and comorbidity.

The attention network test: a characteristic pattern of deficits in children with ADHD

Background

The Attention Network test (ANT) gives measures of different aspects of the complex process of attention. We ask if children with Attention Deficit Hyperactivity Disorder (ADHD) will show a characteristic pattern of deficits on this test.

Methods

The sample included 157 children (M = 10 years) who performed the child version of ANT as participants of the Bergen Child Study. Children with an ADHD diagnosis (N = 45) were compared to a group of children with other diagnoses (N = 55) and a group of children without any diagnosis (N = 57).

Results

The group of children with ADHD showed low accuracy scores and a variable response set, indicating an inattentive response style. No differences were found between the groups on RT and accuracy measures of the alerting, orienting, and conflict networks. A high correlation between full scale IQ (FSIQ) and ANT measures was only found in the ADHD group. When FSIQ score was included as a covariate, the group differences were not statistically significant on any ANT measure.

Conclusion

The present study showed that accuracy and variability measures rather than measures of the three attention networks conveyed the characteristic pattern of deficits in children with ADHD. The results emphasized the importance of including these measures to extend the sensitivity of the ANT, and the importance of reporting results both with and without FSIQ as a covariate.

Psychiatric disorders and MND in non-handicapped preterm children. Prevalence and stability from school age into adolescence

In preterm children (N = 66) without major physical and/or mental handicaps the prevalence of psychiatric disorders and minor neurological dysfunction (MND) was assessed at school age (8-10 years). In adolescence (15-17 years) 43 children were reassessed. The study sample was drawn from a cohort of non-handicapped preterm children (N = 218) hospitalised in a Neonatal Intensive Care Unit because of serious neonatal complications. The findings in the preterm group were compared with two control groups (N = 20 and N = 20) matched for age and sex ratio. The association between psychiatric disorders on the one hand and group status (preterm versus control), MND, IQ and family adversity on the other was explored. At both ages the preterm children exhibited more psychiatric disorders and MND than controls. The very preterm and/or very low birth weight children contributed to the differential psychopathological findings between the preterm and control groups. Besides preterm birth, the prevalence of psychiatric disorders was positively associated with MND and negatively associated with VIQ and family adversity. In the preterm group there was a shift from school age into adolescence into a predominance of anxious and depressive disorders. No significant changes with age were found with respect to the prevalence of MND and psychiatric disorders. Thus, very preterm and/or very low birth weight children are at increased risk of persistent psychiatric disorders, especially anxious and depressive disorders. In preterm children the development of psychopathology seems to be mediated by MND, decreased verbal abilities and family adversity.

Attention-deficit/hyperactivity disorder: a neuropsychological perspective towards DSM-V

Neuropsychological methods and techniques have much to offer in the evaluation of the individual suspected as having Attention-Deficit/Hyperactivity Disorder (ADHD). After a review of the historical evolution of the ADHD concept, incidence and prevalence, and DSM-IV criteria for diagnosis, especially as regards omission related to gender differences, and other associated cultural, familial, socioenvironmental, and subject influences, this paper describes a number of dilemmas and obstacles encountered in clinical practice. Included are the confounds associated with the wide range of possible comorbidities, the insufficiency of current DSM-IV criteria, the emergence of subtype differentiation and its impact on diagnosis and treatment. The complex relationship between neuropsychological constructs and ADHD, and obstacles to valid assessment are also addressed. The complexities associated with a thorough ADHD evaluation are viewed within an impressive and expansive existing scientific framework and recommendations are made for future directions.

Spontaneous attentional fluctuations in impaired states and pathological conditions: a neurobiological hypothesis

In traditional accounts, fluctuations in sustained and focused attention and associated attentional lapses during task performance are regarded as the result of failures of top-down and effortful higher order processes. The current paper reviews an alternative hypothesis: that spontaneous patterns of very low frequency (<0.1 Hz) coherence within a specific brain network ('default-mode network') thought to support a pattern of generalized task-non-specific cognition during rest, can persist or intrude into periods of active task-specific processing, producing periodic fluctuations in attention that compete with goal-directed activity. We review recent studies supporting the existence of the resting state default network, examine the mechanism underpinning it, describe the consequent temporally distinctive effects on cognition and behaviour of default-mode interference into active processing periods, and suggest some factors that might predispose to it. Finally, we explore the putative role of default-mode interference as a cause of performance variability in attention deficit/hyperactivity disorder.

Sustained Attention and Executive Functioning Performance in Attention-Deficit/Hyperactivity Disorder

The aim of this study was to further refine the cognitive phenotype of attention-deficit/hyperactivity disorder (ADHD), with respect to the ability to sustain attention and executive functioning. Participants were 34 boys with ADHD (combined type) and 28 normal controls. The groups were closely matched for age and IQ. All participants were 12 years of age. Both groups performed a computerized sustained attention task and a response interference task. Measures related to speed, accuracy, and time on task were collected. We found that children with ADHD performed slower, less accurately, more impulsively, and with less stability than controls. Both groups produced more errors with increasing time on task, reflecting reduced vigilance. Importantly, no interaction with time on task was found. The overall pattern of results suggests that measures related to accuracy are more informative than measures related to speed of responding in refining the cognitive phenotype of ADHD.

RESPONSE INTERFERENCE AND WORKING MEMORY IN 12-YEAR-OLD CHILDREN

A group of 69 12-year-old children performed three well-known response interference tasks: the Stroop task, the Eriksen flanker task, and the Simon task. Individual differences in accuracy and speed correlated across the tasks. However, there was no correlation between the interference effects on these three tasks. Stroop interference, but not the Simon or flanker effect, was correlated with working memory capacity, as obtained from the WISC-R. These results may help clarify the nature of ADHD, which is characterized by problems with response interference.

Information processing profiles of internalizing and externalizing behavior problems: evidence from a population-based sample of preadolescents

BACKGROUND

The present study explores the relationships between several information processing capacities and internalizing and externalizing behavior problems in a general population sample of 10- to 12-year olds (N = 2,037 51% girls).

METHODS

Parent-reported behavior problems as assessed by the Child Behavior Checklist were used to form four groups of children with 1) neither internalizing nor externalizing problems (n = 1,470), 2) only internalizing problems (n = 237), 3) only externalizing problems (n = 182), and 4) both internalizing and externalizing problems (n = 148). These groups were compared on measures of speed and accuracy from the Amsterdam Neuropsychological Tasks program reflecting the efficiency of several input-, central cognitive-, and output-related information processing capacities.

RESULTS

Children with both internalizing and externalizing problems demonstrated the least efficient performance, followed by children with only externalizing problems, whereas children with only internalizing problems did not differ from children without problems. More specifically, response variability and the ability to maintain and quickly compare information in working memory were found to be related to the severity of problem behavior. The ability to inhibit prepotent responses was related to the type of problem behavior, discriminating between the children with only internalizing problems and only externalizing problems. However, this latter capacity no longer differentiated when controlling for IQ. No differences were found between boys and girls.

CONCLUSIONS

The results suggest that, in general, cognitive processing deficits are more strongly related to the degree than to the type of maladaptive behavior. Furthermore, response variability and working memory may serve as potential markers for identifying high-risk children and response inhibition as an indicator of the type of maladaptive behavior.

Profiles of externalizing behavior problems for boys and girls across preschool: the roles of emotion regulation and inattention

Although externalizing behavior typically peaks in toddlerhood and decreases by school entry, some children do not show this normative decline. A sample of 383 boys and girls was assessed at ages 2, 4, and 5 for externalizing behavior and at age 2 on measures of emotion regulation and inattention. A longitudinal latent profile analysis was performed and resulted in 4 longitudinal profiles of externalizing behavior for each gender. Poor emotion regulation and inattention were important predictors of membership in the chronic-clinical profile for girls, whereas socioeconomic status and inattention were important predictors of membership in the chronic-clinical profile for boys. Results are discussed with respect to the development of adaptive skills that lead to normative declines in externalizing behavior across childhood.

Single dissociation findings of ADHD deficits in vigilance but not anterior or posterior attention systems

Following a distributed network model of visuospatial attention, the authors used an A-X version of the Continuous Performance Test and a covert orienting paradigm to examine the vigilance, anterior, and posterior attention systems. Compared with control participants without attention-deficit/hyperactivity disorder (ADHD), children with the predominantly inattentive (ADHD-I) and combined (ADHD-C) subtypes had lower sensitivity (d') to detect targets from nontargets. Children with ADHD-C, but not ADHD-I, additionally had a highly activated response style (lnbeta). Performance for both subtypes decreased to a greater extent over time in a manner consistent with problems in sustained attention. Together, these results suggest the presence of vigilance system deficits in participants with both ADHD subtypes. However, consistent with previous meta-analytic work, there was no evidence for anterior or posterior system orienting dysfunctions in either subtype.

Efficient allocation of attentional resources in patients with ADHD: maturational changes from age 10 to 29

BACKGROUND

It has been proposed that ADHD is an executive control disorder. Little is known however about the maturation of executive control in ADHD.

METHOD

A cross-sectional study of ADHD patients compared to normal controls tested on a computerized neurocognitive test battery.

PARTICIPANTS

175 patients with ADHD, age 10 to 29, compared to 175 age-matched normal controls.

RESULTS

In every age group, ADHD patients were impaired in measures of psychomotor speed, reaction time, cognitive flexibility, and attention. Participants in both groups improved with age. In tests of executive control, normals improved their performance with shorter reaction times. ADHD patients improved their performance but by adopting a less efficient strategy: Their reaction times increased with age.

CONCLUSIONS

These data support executive control as a "core deficit" in ADHD. In the Stroop and the shifting attention tests, ADHD patients proved to be inefficient in allocating their attentional resources.

Asymmetric deterioration of spatial awareness with diminishing levels of alertness in normal children and children with ADHD

BACKGROUND

There is growing literature suggesting that some children diagnosed with attention deficit hyperactivity disorder (ADHD) can show a significant bias in attention away from left space. Here we examine mechanisms that may underpin these effects in both clinical and non-clinical child populations. Unilateral spatial inattention (unilateral neglect) is a commonly reported consequence of stroke in adults. Although for most patients the problem is relatively transient, persistent forms of neglect are almost exclusively associated with right hemisphere lesions. It has been suggested that this chronicity may result from co-existing disruption to right hemisphere dominant systems that mediate alertness. Here we present two studies examining the relationship between sustained attention and left spatial awareness in childhood.

METHOD

In the first, normal children without the ADHD diagnosis were administered a non-spatial test of sustained attention/alertness. Children who performed poorly at this task, relative to their more attentive peers, showed a modest but reliable delay in awareness of left-sided visual information. Furthermore, attention towards the left declined for both groups as a function of time-on-task, suggesting a significant within-subject modulatory effect of alertness on spatial awareness. The second study examines this relationship in children referred to clinical services for attention problems. Irrespective of their final diagnosis, children were divided into two groups according to their performance in sustained attention/alertness tasks.

RESULTS

The results suggest that, regardless of the children's clinical diagnosis, diminished sustained attention/alertness levels formed the strongest predictor of relatively delayed awareness of information presented within left visual space. Two children within this group exhibited signs of hitherto undetected spatial neglect as severe as that observed in some brain-injured adults.

CONCLUSIONS

Clinical and theoretical implications are discussed.

Chemotherapy and attentional dysfunction in survivors of childhood acute lymphoblastic leukemia: effect of treatment intensity

BACKGROUND

Central nervous system (CNS) directed chemotherapy is replacing prophylactic cranial irradiation in treatment protocols for childhood acute lymphoblastic leukemia (ALL), mainly to reduce long-term neuropsychological sequelae. We evaluated the effects of chemotherapy on attentional function in survivors of ALL and examined whether possible deficits are related to treatment intensity.

METHODS

In a multi-center study, we compared attentional function in 36 children at least 1 year after finishing treatment with chemotherapy only for ALL, with a cancer control group consisting of 39 Wilms tumor patients and with 110 healthy children. We differentiated between standard- and intensified ALL treatment. The role of previously reported risk factors for neuropsychological deficits was also assessed.

RESULTS

After chemotherapy, attentional deficits were detected in patients with ALL, but not in Wilms tumor patients. Children treated according to standard ALL protocols performed worse than healthy controls on only 1 of 10 outcome measures (P = 0.004), while those who had received intensified treatment performed worse on four outcome measures (0.0001 < P < 0.004). Higher treatment intensity, young age at diagnosis, and female gender were associated with worse performance.

CONCLUSIONS

CNS-directed chemotherapy, even in the absence of cranial irradiation, is associated with attentional dysfunction in survivors of childhood ALL, particularly in case of intensified treatment protocols. These sequelae stress the importance of reducing doses of neurotoxic chemotherapy as much as possible in the design of future treatment protocols for ALL.

[Can a specific assessment of attention contribute to the differential diagnostics of psychiatric disorders?]

OBJECTIVES

The present study examined whether or not children and adolescents with clinical symptoms can be differentiated according to the quantitative and qualitative aspects of attention.

METHODS

Eighty-eight probands (ages 10-18 years) assigned to seven ICD-10 diagnostic groups were studied for differences in their attention profiles. An attention task (Frankfurter Aufmerksamkeits Inventar--FAIR), (Moosbrugger & Oehlschlägel, 1996) validated multifold among children and adolescents in the domain of psychiatry was applied. This task covers three attention functions. Two of them are quantitative: selective attention and continuity of attention, while the third is qualitative: self-control.

RESULTS

Overall, two distinctly different group-specific attention profiles evolved. These differed mainly in terms of self-control. Whereas all of the diagnostic groups studied showed relatively normal selective attention and normal continuity of attention, two groups exhibited substantial differences with regard to self-control. Particularly children and adolescents with schizophrenia showed very poor self-control, as did those with hyperkinetic disorder, conduct disorder, depressive disorder, or compulsive disorder. In contrast, children and adolescents with eating disorders or other anxiety disorders had a high level of self-control.

CONCLUSIONS

Thus, the self-control function was found to be a strong attention parameter for the differential diagnosis of a clinically conspicuous population of children and adolescents.

Reliabilität von Aufmerksamkeits- und verbalen Gedächtnistests bei gesunden Kindern und Jugendlichen - Implikationen für die klinische Praxis

Zusammenfassung: Fragestellung: Die neuropsychologische Diagnostik eignet sich zur differenzierten Beschreibung von kognitiven Leistungen bei Patienten mit kinder- und jugendpsychiatrischen Erkrankungen. In dieser Arbeit werden zunächst ein kurzer theoretischer Hintergrund für die neuropsychologischen Funktionen Aufmerksamkeit und verbales Gedächtnis gegeben und ausgewählte klinische Befunde dargestellt. Des Weiteren wird ein Beispiel einer neuropsychologischen Testbatterie vorgestellt, die im Kinder- und Jugendbereich eingesetzt werden kann. Methodik: Die Retest-Reliabilität dieser Testbatterie wurde in einem Wiederholungszeitraum von 6 Wochen bei 33 gesunden Kindern untersucht. Ergebnisse: Generell konnte eine gute Reliabilität nachgewiesen werden, obwohl es zwischen einigen abhängigen Variablen Unterschiede gab. Lerneffekte aufgrund der Wiederholung wurden vornehmlich bei den jüngeren Kindern nachgewiesen. Schlussfolgerung: Die ausgewählten neuropsychologischen Tests scheinen für die klinische Anwendung geeignet zu sein, wie z. B. die Untersuchung von kognitiven Defiziten und die Evaluierung von psychopharmakologischen Behandlungen. Es ist jedoch zu beachten, dass in Abhängigkeit vom Alter die Retest-Reliabilität unterschiedlich ist.