Neuropsychological functioning in nonreferred siblings of children with attention deficit/hyperactivity disorder

The goal of this study was to assess neuropsychological functioning in nonreferred siblings of children with attention deficit/hyperactivity disorder (ADHD). Participants were 156 siblings of ADHD probands with (N = 40) and without (N = 116) ADHD (according to criteria of the Diagnostic and Statistical Manual of Mental Disorders (3rd edition, revised; American Psychiatric Association, 1987) and 118 siblings of non-ADHD normal controls of similar age, IQ, and grade level. Information on attention, executive, and memory functions was obtained in a standardized manner without knowledge of clinical status. Compared with siblings of controls, siblings with ADHD were significantly impaired on the Stroop test and on verbal learning and memory. In contrast, siblings without ADHD were similar to controls on virtually all measures. These data suggest that some executive, attention, and verbal learning deficits are found in nonreferred individuals with ADHD but that neuropsychological deficits are unlikely to constitute an endophenotype to ADHD.     

The self-perceptions and attributions of attention deficit hyperactivity disordered and nonreferred boys

Compared the self perceptions and attributions of attention deficit hyperactivity disordered (ADHD) and control boys. The ADHD boys viewed themselves as no worse than control boys on self-perceived competence and global selfworth, especially when internalizing symptomatology was taken into account statistically through covariance analyses. In terms of attributions, the ADHD boys were more likely to take responsibility for social successes and less likely to take responsibility for social failures than the control boys. Although the ADHD boys scored significantly higher on the Children's Depression Inventory, this difference was no longer significant when items dealing with behavior, school, and social problems were excluded. The results are discussed in terms of their implications for understanding how the attributions and selfperceptions of ADHD boys may mediate their performance in challenging academic and social situations.An earlier version of this paper was presented at the 1992 Annual Meeting of the Society for Research in Child and Adolescent Psychopathology, Sarasota, Florida. The first author was supported in part by grants from the National Institute of Mental Health (MH47390 and MH48157) and the Clinical Research Center (MH30915). The second author was supported in part by grants from the National Institute on Alcohol Abuse and Alcoholism (AA06267), the National Institute on Drug Abuse (DA05605), and the National Institute of Mental Health (MH48157). The fourth author was supported by a grant from the College of Arts and Sciences of the University of Kentucky.     

Facial affect interpretation in boys with attention deficit/hyperactivity disorder.

Recent studies have produced mixed evidence of impairments in facial affect interpretation for children with attention deficit/hyperactivity disorder (ADHD). This study investigated the presence and nature of such impairments across different stimulus formats. Twenty-four boys with ADHD and 24 age-matched comparison boys completed a 72-trial task that included facial expressions of happiness, sadness, fear, anger, surprise, and disgust. Three versions of each expression were used: a static version, a dynamic version, and a dynamic version presented within a relevant situational context. Expressions were also presented in one of two portrayal modes (cartoon versus real-life). Results indicated significant impairments for boys with ADHD on two of the six emotions (fear and disgust), which were consistent across stimulus formats. Directions for further research to identify mediating factors in the expression of such impairments in children with ADHD are discussed.     

On-line story representation in boys with attention deficit hyperactivity disorder

Children with attention deficit hyperactivity disorder (ADHD) face an increased risk of poor achievement in school. Thus, knowledge of the cognitive processing abilities of children with ADHD is critical to understanding and improving their academic performance. Although many studies have focused on the specific nature of the attention deficit experienced by children with ADHD, few have examined higher order cognitive processing such as comprehension of stories. The present study examined the processes of encoding story information, building a story representation, and modifying a story representation in boys with ADHD and nonreferred boys. Boys were asked to narrate a story from a picture book twice. Boys with ADHD showed deficits in representing goals and goal plans in their narrations, as compared to nonreferred boys. Boys with ADHD also committed more errors than nonreferred boys, but did correct certain types of errors on their second telling. Implications are discussed in terms of future research needed to identify the cognitive deficits that account for these narrative deficits.     

Impairment of executive functions in boys with attention deficit/hyperactivity disorder.

The main aim of the present study is to compare the efficiency of executive control processes in 24 boys with attention deficit/hyperactivity disorder (ADHD) and 58 normal controls of similar age (between 8 and 11 years). Three reaction time (RT) paradigms were utilized: a dual task that requires coordination of two tasks responses, a shift task that makes it necessary to disengage attention from one task and engage into another one, and a stimulus-response spatial compatibility task that requires participants to inhibit a prepotent response. Another purpose of the study is to examine whether Barkley's (1997) executive dysfunction or Sergeant et al.'s (1999) resource allocation/arousal model best account for the behavioral deficits associated with ADHD. Examination of raw RT data showed significantly poorer performance in ADHD children with respect to age-matched controls on both the higher-level cognitive functions of executive control and on lower-level abilities (e.g., speed of processing) of all tasks of this study. However, using proportional transformations of raw RT data, we could demonstrate that, in addition to differences in processing speed, also executive control processes were significantly impaired in children with ADHD.     

Sensitivity to reward frequency in boys with attention deficit hyperactivity disorder.

Compared the sensitivity of boys with and without attention deficit hyperactivity disorder (ADHD) to differences in reward frequency. Fifteen boys with ADHD as diagnosed in the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) and a matched control group completed a signal-detection task in which correct identification of 1 stimulus was rewarded 3 times as often as correct identification of the other. Boys in the ADHD group completed the task twice, on and off medication. Group differences emerged in response bias toward the more frequently rewarded alternative. Boys in the control group showed a stable pattern of response bias, irrespective of which alternative they were last rewarded on. Boys in the ADHD group showed different patterns of response bias following rewards on the 2 alternatives. These results suggest children with ADHD were more sensitive to individual instances of reward compared with controls, whose response bias is governed more by their reinforcement history. Methylphenidate improved discriminability and reduced sensitivity to individual instances of reward in the boys with ADHD.     

Supraspan verbal memory in attention deficit disorder with hyperactivity normal and reading-disabled boys

To assess memory problems associated with attention deficit disorder with hyperactivity (ADDH) and reading disability (RD), nonverbal subspan, span, and supraspan measures was administered to 30 ADDH, 30 normal, and 24 RD boys, ages 7 to 12. Results from the supraspan verbal measures, which included word lists and related and unrelated paired associates, are reported. Across all verbal tasks, deficits became most apparent in ADDH boys on measures requiring organized, deliberate rehearsal strategies, sustained strategic effort, and careful consideration of response alternatives. This pattern suggests impaired self-regulatory or executive processes. RDs showed more generalized deficits across the verbal measures, suggesting problems with verbal processing. Recent studies supporting this interpretation are reviewed.This research was partially supported by Grant MA-6913 from the Medical Research Council of Canada. We are grateful for the help of Rhonda Amsel in the various stages of this project.     

Salience and temporal sequencing of time-related actions in boys with attention deficit/hyperactivity disorder.

Twenty-four 8- to 12-year-old boys with ADHD and 24 non-ADHD boys matched on age and IQ viewed an edited, nondialogue portion of a humorous television program to examine performance on a task requiring attention to and recall of temporal information. Participants were required to retell the story as closely as possible, to complete a picture-prompted sequencing task taken from the story, and to identify time-saving actions taken by the central character. Measures were also obtained of the number of prospective, retrospective, or present time-related references made and whether participants correctly identified the overarching time theme of the story. Significant group differences in favor of the comparison boys were evident in the total number of actions recalled and the number of events recalled in sequence. When controlling for poorer memory performance in boys with ADHD, however, there was no significant main effect of diagnostic group. A logistic regression analysis controlled for poorer memory performance indicated no significant differences between the number of boys with and without ADHD who correctly identified the overarching time theme of the story.     

Hand preference in attention deficit hyperactivity disorder

In our Outpatient Department, we studied 56 subjects (41 males, 15 females; aged 5-16 yr.) with Attention Deficit Hyperactivity Disorder (ADHD) with respect to hand use in functional tasks via parental report. Left-hand use was markedly preferred, compared to that of a control group, more for complex than simple and for external (touching food and objects) than internal (scratching, rubbing eyes) tasks, suggesting a deficit in cerebral control of right-hand use. More patients were reported to have a left-hand preference than in the non-ADHD population. Furthermore, extent of laterality was greater for complex than simple external tasks and for external than for internal.     

External validation of oppositional disorder and attention deficit disorder with hyperactivity

Validity of the distinction between oppositional disorder (OD) and attention deficit disorder with hyperactivity (ADDH) was examined in a sample of 6- to 12-year-old boys with behavior problems. Problem identification, cognitive/attentional, family context, and behavioral symptom differences were examined among nine boys with OD only, 20 with ADDH, 40 with comorbid OD and ADDH, and 28 with neither disruptive behavior disorder. Systematic comparisons of groups including and excluding the OD and ADDH diagnoses were undertaken to determine the existence of pure OD and pure ADDH disorder effects. The most consistent result was the lack of evidence for either pure OD or pure ADDH effects. Most of the significant findings reflected differences between the nondisruptive (neither) and comorbid groups. The results support the importance of comorbidity, but they provide little support for disorder-specific distinctions between oppositional and attention deficit disorders.     

Inhibition and attention deficit hyperactivity disorder in adults

The inhibitory account of attention deficit hyperactivity disorder (ADHD) was tested by examining the performance of college-aged adults on a variety of inhibitory tasks. The poorer performance of adults with ADHD compared with controls on negative priming, stopping, and continuous performance tasks, combined with similar group performances on a test of working memory capacity, indicates a specific inhibitory deficit as opposed to a general limitation in attentional capacity. Overall results provide evidence for extending the inhibitory deficit hypothesis to adult ADHD, not only for mechanisms of response (or motor) inhibition but also for mechanisms of cognitive inhibition.     

Effect of stimulant medication on lower extremity response time of boys with attention deficit hyperactivity disorder

Children with attention deficit hyperactivity disorder (ADHD) have been labeled as "inefficient movers"; however, little research has examined the effect of stimulant medication on lower extremity movements. 16 boys, 11 to 13 years old, with ADHD performed a lower-limb choice-response time task, both on and off medication. When nonmedicated, children had significantly slower reaction times to all three targets and significantly slower movement times for the contralateral and midline movements. For both conditions, children had significantly faster movement time when using the right leg than the left leg. These findings suggest that movement characteristics of children with ADHD are different under medicated and nonmedicated situations.     

Self-paced learning in children with attention deficit disorder with hyperactivity

Attention deficit (ADDH) children self-paced the delivery of response pairs for paired-associate learning at about the rate previously shown to be conducive to relatively good learning in attention deficit. The self-pacing opportunity did not seem either to impair or to enhance the learning performance. On methylphenidate they paced themselves at about the same rate but learned much more. Stimulant therapy does not help by slowing the child down but permits more effective memorizing at the same presentation rate.     

Perceptual asymmetries in normal children and children with attention deficit/hyperactivity disorder

Perceptual asymmetries in normal right-handed children (7-12 years of age) and children with attention deficit/hyperactivity disorder (ADHD), combined type, were investigated using various chimeric stimuli in free-viewing conditions. In the face-matching task, participants indicated which of two symmetrical face chimeras more closely resembled the original; in the chimeric faces task, participants indicated which of a pair of faces appeared happier; and in the grey scales task participants indicated which of two shaded rectangles appeared to be darker overall. Leftward biases were found for normal children with no effects of age. Contrary to expectations, normal leftward biases were also found for ADHD children in the face-matching and the chimeric faces tasks; however, a significant leftward bias was not observed in the grey scales task. The absence of anomalous perceptual bias in ADHD children on these purely perceptual tasks, suggests that anomalous perceptual asymmetries observed in other tasks (line bisection and cancellation tasks) may have been confounded by the motor response, and/or the explicit spatial components of those tasks.     

Implicit and explicit memory performance in children with attention deficit/hyperactivity disorder

The present investigation examined implicit and explicit memory in 20 children diagnosed with attention deficit/hyperactivity disorder (AD/HD) and 20 matched controls. Consistent with previous research, children with AD/HD performed more poorly than controls on an explicit test of long‐term memory for pictures. New results were that (a) there was no deficit on an implicit memory test for equivalent material and that (b) the observed deficit in explicit memory operated over and above any effects of depression/anxiety. Another finding to emerge was that AD/HD children had greater difficulty than controls in identifying pictures of objects that were presented in an unusual form, either rotated or degraded. Overall, the pattern of results is interpreted in terms of deficient effortful/resource‐intensive processes in AD/HD but intact automatic processes.     

Rates of forgetting in attention deficit hyperactivity disorder

The present study evaluated rates of forgetting on verbal and nonverbal memory tests in children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD). Although children with ADHD are known to have poor organizational and attentional problems that may impair memory performance, we hypothesized that savings scores would remain intact, because poor recall reflects difficulty with initial learning versus memory per se. Fifty-seven children diagnosed with ADHD were administered tests of nonverbal memory (Rey-Osterreith Complex Figure) and verbal memory (Story Memory, Wide Range Assessment of Memory and Learning) as part of a comprehensive neuropsychological evaluation. Subjects showed no evidence of rapid forgetting of information across the delay on either nonverbal memory (mean savings score=93%) or verbal memory (mean savings score=88%) tests. Cognitive remediation for children with ADHD should address ways to initiate and execute organizational strategies so that more information is learned upon immediate presentation.     

A psychophysical measure of attention deficit in children with attention-deficit/hyperactivity disorder

The authors explored the temporal mechanism of attention deficit in children with attention-deficit/hyperactivity disorder (ADHD). In rapid serial visual presentation tasks in which two targets (T-sub-1 and T-sub-2) were presented in close temporal proximity among distractors, participants tried to identify T-sub-1 and detect T-sub-2 in one (dual-task) experiment and only to detect T-sub-2 in a second control (single-task) experiment. The sensitivity of T-sub-2 detection was analyzed using signal detection theory. The attentional blink--the impairment in T-sub-2 detection following the identification of T-sub-1--was increased in magnitude and protracted in the patients. Moreover, some ADHD children appeared to have a blink largely normal in magnitude but temporally displaced toward a later time. The authors hypothesize that a slower closing of the attention gate may mediate this specific attention impairment in ADHD children.