The impact of stimulants on a clinical measure of attention in children with ADHD.

The effect of stimulant medication on the attentional functioning of 23 children (8-12 yrs) with attention deficit/hyperactivity disorder (ADHD) was investigated. Significant main effects of medication and TEA-Ch subtests were found, however there was no significant interaction. Planned contrasts showed that stimulants improved performance on the sustained attention, but not the selective or divided attention, subtests. Similar to previous studies, the results indicate that stimulants improve sustained attention in children with ADHD. Significant effects of stimulants on selective and divided attention, however, were not as apparent. Therefore, care must be taken when using TEA-Ch subtests to assess performance change subsequent to stimulant administration.     

Positive emotional attention bias in young children with symptoms of ADHD

Children with attention-deficit/hyperactivity disorder (ADHD) often experience emotional dysregulation. Dysregulation can arise from heightened attention to emotional stimuli. Emotional attention biases are associated with a number of adverse socioemotional outcomes including reward sensitivity and externalizing behaviors. As reward sensitivity and externalizing behaviors are common in children with ADHD, the aim of the current study was to determine whether emotional attention biases are evident in young children with clinically significant ADHD symptoms. To test this, children with (n = 18) and without (n = 15) symptoms of ADHD were tested on a Dot Probe task. Provided recent evidence that emotional attention biases are attenuated by sleep, the task was performed before and after overnight sleep. Children with ADHD symptoms displayed positive, but not negative, attention biases at both time points, whereas typically developing children did not preferentially attend toward or away from positive or negative stimuli. Sleep did not alter attention biases in either group. Collectively, these results indicate that children with ADHD symptoms have stable, positive attention biases.     

Latent inhibition and asymmetrical visual-spatial attention in children with ADHD.

The research was designed to determine whether the purported hemispheric asymmetries that are associated with attention deficit/hyperactivity disorder (ADHD) affect performance on a selective attention visual search task, and whether any obtained asymmetry will be modulated by methylphenidate. Two groups of children (8-15 years) with ADHD, one with methylphenidate treatment (ADHD+) and one without (ADHD+), were compared to matched controls on a two-stage visual search task. The task assessed right-left visual field asymmetries and the effects of changing a previous distractor into a target. Such a procedure, related to latent inhibition (LI; poorer performance to a previously irrelevant stimulus than to a novel one), can provide evidence for dysfunctional processing of irrelevant stimuli. All three groups exhibited the LI effect. The ADHD group, however, exhibited less LI for left- than right-side targets, an effect absent in the control and ADHD+ groups, suggesting a lateralized attentional deficit for ADHD+ that was normalized by methylphenidate.     

The impact of words on children with ADHD and DAMP Consequences for psychoanalytic technique

Children with attention-defi cit/hyperactivity disorder (ADHD) and disorder of attention, motility control, and perception (DAMP) are often sensitive to the analyst's interventions. This is not always due to the literal import of the intervention. The children sometimes react as if the words were dangerous concrete objects, which they must physically fend off. The author traces this phenomenon to the child's unstable internal situation. A bad, un-containing internal object is easily awakened and threatens to expel the analyst's words independently of their content. This results in violent clinical situations. Infant research and psychoanalytic work with infants and mothers evince how a complex semiotic process develops between mother and baby. The prerequisite for this process to get started and maintained is a secure external object, which gradually is internalized. Findings from developmental research and clinical infant work are used to illuminate analytic work with children with ADHD and DAMP. Vignettes demonstrate how important it is for the analyst to phrase interpretations after having gauged the state of the analysand's internal object as well as his/her own countertransference. If this is overlooked, the psychoanalytic dialogue easily capsizes. The author provides some technical recommendations on the psychoanalysis of these children. As part of the theoretical discussion he raises the general question of how the representations, which the baby forms in interaction with the mother, and the analysand forms in interaction with the analyst, should be classifi ed. Rather than dividing them into bipartite thing- or word-presentations (Freud), the author suggests C. S. Peirce's tripartite semiotic classifi cation in that the baby forms representations of icons, indices, and symbols.     

A controlled clinical comparison of attention performance in children with ADHD in a virtual reality classroom compared to standard neuropsychological methods.

In this initial pilot study, a controlled clinical comparison was made of attention perforance in children with attention deficit-hyperactivity disorder (ADHD) in a virtual reality (VR) classroom. Ten boys diagnosed with ADHD and ten normal control boys participated in the study. Groups did not significantly differ in mean age, grade level, ethnicity, or handedness. No participants reported simulator sickness following VR exposure. Children with ADHD exhibited more omission errors, commission errors, and overall body movement than normal control children in the VR classroom. Children with ADHD were more impacted by distraction in the VR classroom. VR classroom measures were correlated with traditional ADHD assessment tools and the flatscreen CPT. Of note, the small sample size incorporated in each group and higher WISC-III scores of normal controls might have some bearing on the overall interpretation of results. These data suggested that the Virtual Classroom had good potential for controlled performance assessment within an ecologically valid environment and appeared to parse out significant effects due to the presence of distraction stimuli.     

Verbal fluency over time as a measure of automatic and controlled processing in children with ADHD

The performance of ADHD children on semantic category fluency (SCF) versus initial letter fluency (ILF) tasks was examined. For each participant, word production was recorded for each 15-s time slice on each task. Performance on both fluency tasks was compared to test the hypothesis that children with ADHD are characterized by a performance deficit on the ILF task because performance on this task is less automated than performance on the SCF. Children classified with ADHD (N = 20) were compared to children with other psychopathology (N = 118) and healthy controls (N = 130). Results indicated that the groups could not be differentiated by the total number of words produced in 60 s in either fluency task. As hypothesized, a significant interaction of group by productivity over time by type of fluency task was found: ADHD children had more problems finding words in the first 15 s of the IFL than did children in the other two groups, and as compared with their performance on the SCF. Results were taken to indicate that children with ADHD symptoms show a delay in the development of automating skills for processing abstract verbal information.     

Visuo-spatial working memory span: a sensitive measure of cognitive deficits in children with ADHD.

Working memory (WM) has been hypothesised to be impaired in attention-deficit/hyperactivity disorder (ADHD). However, there are few studies reported on tests measuring visuo-spatial WM (VSWM) in ADHD. Some of these studies used paradigms including episodic memory, others only used low memory loads. In the present study we used a VSWM test that has not been used previously in ADHD research. The sensitivity of the VSWM test and a choice reaction time (CRT) test was evaluated in a pilot study by comparing them to two commonly used tests in ADHD-research; the Continuous Performance Test (CPT) and a Go/no-go test, in children with and without ADHD. The groups differed significantly in performance on the VSWM test (P < .01) and CRT (P < .05) but not on the CPT (P > .1) or on the Go/no-go test (P > .1). The results from the VSWM and CRT tests were replicated in a larger sample of participants (80 boys; 27 boys with ADHD and 53 controls, mean age 11.4 years). The difference between the groups was significant for both the VSWM test (P < .01) and the CRT test (P < .01). The effect size (ES) of the VSWM test was 1.34. There was a significant age-by-group interaction on the VSWM test, with larger group differences for the older children (P < .01). Our results show that the VSWM test is a sensitive measure of cognitive deficits in ADHD and it supports the hypothesis that deficits in VSWM is a major component of ADHD.     

Performance of children with attention deficit hyperactivity disorder (ADHD) on a test battery of impulsiveness.

Children with ADHD were compared to healthy controls on a task battery of cognitive control, measuring motor inhibition (Go/No-Go and Stop tasks), cognitive inhibition (motor Stroop and Switch tasks), sustained attention and time discrimination. Children with ADHD showed an inconsistent and premature response style across all 6 tasks. In addition they showed task-specific impairments in measures of sustained attention, time discrimination, and motor inhibition, but spared cognitive inhibition. Measures of impairment correlated with behavioral hyperactivity and with each other, suggesting that they measure interrelated aspects of a multifaceted construct of cognitive impulsiveness. The task battery as a whole showed 76% correct discrimination of cases and controls.     

The clinical neuropsychology of attention in school-aged children.

100 children from the north-east of England, aged between 7 and 13 years of age, completed an assessment of intellectual ability and an attention battery based on the work of Mirsky, Anthony, Duncan, Ahearn, & Kellam (1991). Factor analysis was generally supportive of the Mirsky et al. (1991) model. Replication of the adult model produced the same four factors: sustain, encode, focus-execute and shift. Replication of the child model produced a three-factor model in which the encode and focus-execute factors combined. An extended model resulted in the introduction of a new factor labelled errors of processing. The scores on attention factors were found to have a reasonable level of independence from intellectual ability.     

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.     

When attention is intact in adults with ADHD

Is covert visuospatial attention—selective processing of information in the absence of eye movements—preserved in adults with attention-deficit/hyperactivity disorder (ADHD)? Previous findings are inconclusive due to inconsistent terminology and suboptimal methodology. To settle this question, we used well-established spatial cueing protocols to investigate the perceptual effects of voluntary and involuntary attention on an orientation discrimination task for a group of adults with ADHD and their neurotypical age-matched and gender-matched controls. In both groups, voluntary attention significantly improved accuracy and decreased reaction times at the relevant location, but impaired accuracy and slowed reaction times at irrelevant locations, relative to a distributed attention condition. Likewise, involuntary attention improved accuracy and speeded responses. Critically, the magnitudes of all these orienting and reorienting attention effects were indistinguishable between groups. Thus, these counterintuitive findings indicate that spatial covert attention remains functionally intact in adults with ADHD.     

The alliance in a friendship coaching intervention for parents of children with ADHD

The alliance between parent and therapist was observed in a group-based parent-training intervention to improve social competency among children with attention-deficit/hyperactivity disorder (ADHD). The intervention, called Parental Friendship Coaching (PFC), was delivered to 32 parents in small groups as part of a randomized clinical trial. PFC was delivered in eight, 90-minute sessions to parents; there was no child treatment component. Observed parent–therapist alliance recorded among 27 of the parents was measured using the Therapy Process Observational Coding System—Alliance scale (TPOCS-A; McLeod, 2005). Early alliance and change in alliance over time predicted improvements in several parenting behaviors and child outcomes, including peer sociometrics in a lab-based playgroup. These preliminary findings lend support to the importance of examining the parent–therapist alliance in parent-training groups for youth social and behavioral problems.     

The effect of reinforcement variables on inhibition in children with ADHD.

Behavioral inhibition, often cited as a central deficit in children with ADHD, has been shown to change in response to reinforcement. In this preliminary investigation, children with ADHD (n= 20) and matched controls (ages 7 to 12) completed a new version of the stop signal paradigm, the Fire Fighter Game, a measure of inhibition of a prepotent motor response, under three conditions: (1) no reinforcement; (2) immediate reinforcement; and (3) delayed reinforcement. In all conditions, the stop signal reaction time (SSRT) of children with ADHD was consistently longer than controls. Both groups improved significantly with reinforcement, and there was no strong evidence that immediate reinforcement was more effective than delayed reinforcement. However, it appeared that the reason for the changes in SSRT in response to reinforcement differed between the groups. Children in the control group responded faster on go trials, whereas children with ADHD improved their ability to inhibit responding with shorter stop delays. The relevance of these findings is discussed in terms of current theories of ADHD.     

Relating lab to life: Decrements in attention over time predict math productivity among children with ADHD

A child’s ability to sustain attention over time (AOT) is critical in attention-deficit/hyperactivity disorder (ADHD), yet no prior work has examined the extent to which a child’s decrement in AOT on laboratory tasks relates to clinically-relevant behavior. The goal of this study is to provide initial evidence for the criterion validity of laboratory assessments of AOT. A total of 20 children with ADHD (7–12 years of age) who were enrolled in a summer treatment program completed two lab attention tasks (a continuous performance task and a self-paced choice discrimination task) and math seatwork. Analyses focused on relations between attention task parameters and math productivity. Individual differences in overall attention (OA) measures (averaged across time) accounted for 23% of the variance in math productivity, supporting the criterion validity of lab measures of attention. The criterion validity was enhanced by consideration of changes in AOT. Performance on all laboratory attention measures deteriorated as time-on-task increased, and individual differences in the decrement in AOT accounted for 40% of the variance in math productivity. The only variable to uniquely predict math productivity was from the self-paced choice discrimination task. This study suggests that attention tasks in the lab do predict a clinically-relevant target behavior in children with ADHD, supporting their use as a means to study attention processes in a controlled environment. Furthermore, this prediction is improved when attention is examined as a function of time-on-task and when the attentional demands are consistent between lab and life contexts.     

Activation of brain attention systems in individuals with symptoms of ADHD

Previous research investigating attention and impulse control in individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) has largely ignored the symptomatic differences among the three subtypes of ADHD: ADHD-Inattentive Type, ADHD-Hyperactive/Impulsive Type, and ADHD-Combined Type. The present study examined attention and impulse control by focusing on these subtypes. Based on their self-reported symptoms of ADHD, participants belonged to one of four groups: ADHD-Inattentive, ADHD-Hyperactive/Impulsive, ADHD-Combined, and control. Cortical activity was recorded from participants during performance of a Go/NoGo task. The event-related potentials (ERP) measured at frontal and posterior sites discriminated between the control group and participants with symptoms of ADHD. The control group consistently exhibited a higher P3 amplitude than all the ADHD groups. The main difference occurred at the frontal site, indicating that individuals with ADHD symptoms have deficits in the anterior attentional system, which mediates signal detection. Behavioral measures of signal sensitivity revealed that the ADHD-Inattentive and the ADHD-Hyperactive/Impulsive groups had more difficulty with the attention-demanding Go/NoGo respond-to-target task, while behavioral measures of response bias indicated that the ADHD-Hyperactive/Impulsive and the ADHD-Combined groups responded more liberally in the inhibition-demanding Go/NoGo suppress-to-target task.