Effects of reward on delayed reaction time task performance of hyperactive children

This experiment was designed to investigate the effects of continuous, partial, and noncontingent schedules of reward, as well as the withdrawal of rewards, on the performance of hyperactive and normal control children on a delayed reaction time task. Although noncontingent reward resulted in faster reaction times for control subjects, performance of hyperactives deteriorated under noncontingent reward and improved when it was withdrawn. Also, reaction times of controls during extinction remained superior to baseline, whereas performance of hyperactives returned to baseline level. It was suggested that these and other findings reviewed point to an unusual sensitivity to rewards in hyperactive children.     

The effects of reward and punishment on reaction times and autonomic activity in hyperactive and normal children

The performance of hyperactive and control children was compared on a delayed reaction time task under three reinforcement conditions: reward, punishment, and reward plus punishment. Hyperactives had slower and more variable reaction times, suggesting an attentional deficit. Although each of the three reinforcement conditons was successful in improving reaction times for both subject groups, reward led to a significant increase in impulsive responses in the hyperactive children. Autonomic data revealed that reward also increased arousal to a greater extent than punishment or reward plus punishment. Although resting skin conductance was not different in the two groups of subjects, hyperactives produced fewer specific autonomic responses to signal stimuli.     

Focused attention in pervasively hyperactive children

This experiment was designed to investigate the hypothesized distractibility of hyperactive children in a focused attention task. Distractibility was defined in terms of Shiffrin and Schneider's model of focused attention as the ability to ignore irrelevant in favor of relevant information. Failure to inhibit processing of irrelevant information indicates a focused attention deficit. Task efficiency in all children decreased when irrelevant information was presented. The mean reaction time, within-subject variance of reaction time, and error percentage all increased compared with a nondistraction condition. Thus, the demands of focused attention, as formulated in the model, were measured optimally. Since hyperactives and controls did not differ significantly with respect to task efficiency in the distraction condition, a focused attention deficit in hyperactives was not demonstrated. The hyperactives did nevertheless make more errors and their responding was more variable than the controls. However, the difference in error percentages between hyperactives and controls was associated with the difference in IQ. It is speculated that the variable responding in hyperactives is caused by a less optimal state of performance unrelated to distractibility.The authors wish to thank L. Leertouwer for making the drawings. This research was supported by grants from the Netherlands Foundation for the Advancement of Pure Research (ZWO) and the Professor Duijker Fund.     

Performance and activity of hyperactive and normal boys as a function of distraction and reward

Twenty-five hyperactive boys and 25 controls matched for age, social class, and race were compared on three performance tasks (coding, tone discrimination, and connecting dots) in two settings (nondistracting and highly distracting). Control Ss performed significantly better than did hyperactives in all conditions, except during tone discrimination and connecting dots in the nondistracting setting. Distraction decreased performance for both groups on the coding task and for hyperactives on the tone discrimination task, but significantly improved performance for controls on the connecting dots task. Distraction, where detrimental, was not significantly more so for hyperactives than for controls. The effect of reward on coding performance was studied in the distracting condition; reward produced the best performance for both groups, but significant differences between groups were not found.This research was supported in part by U.S. Public Health Service Training Grant (in Biological Sciences) No. MH07081.The participation of the following people in helping to design this research study and collect data is hereby acknowledged: David Bremer, Ted Goltz, Ruth Rosenthal, and Michael Stern.     

Visual and auditory attention performance in hyperactive children: Competence or compliance

The effect of self-control and compliance on the attentional performance of hyperactive children was assessed. Visual and auditory attention tasks were presented in conditions in which the experimenter was either absent and therefore not imposing external control, or present and therefore imposing some degree of control. There was no difference in performance between hyperactives and controls when the experimenter was present, but the hyperactives' performance showed a greater deterioration than controls when the experimenter was absent. The amount of movement displayed during the tasks was greater for hyperactives and increased more for this group during experimenter-absent conditions. The results support the contention that noncompliance is a major contributor to the poor performance of hyperactive children, which can be seen as an application deficit rather than an ability deficit. These findings have relevance for the current debate on the association between hyperactivity and conduct disorder, and from an applied perspective they serve to stress the importance of situational contributors to the problem behaviors of hyperactive children.     

Deficit in Response Inhibition in Children with Attention Deficit/Hyperactivity Disorder (ADHD): Impact of Motivation?

To date, neuropsychological and psycho-physiological studies have revealed inconsistent results regarding an executive or motivational deficit explaining the response inhibition deficit in children with attention deficit/hyperactivity disorder (ADHD). Research on differentiating neuropsychological processes in ADHD subtypes is still scarce. Therefore, the motivational impact on response inhibition among boys with ADHD was examined in this study. In the first study, 19 boys with ADHD-combined type (ADHD-C) and 19 age-matched healthy control subjects performed a modified Go/No-Go task with the following experimental conditions: neutral, auditory feedback, reward, response cost, and reward/response cost. Performance and physiological data (heart rate and skin conductance responses) were recorded. In a second study with the modified Go/No-Go task, data for six children with ADHD-C, six with ADHD-inattentive subtype (ADHD-I), and six healthy control subjects were compared. Neither of the two studies revealed group by condition interactions. In study 1, boys with ADHD-C generally made more commissions and omissions compared to the control group. However, feedback significantly improved the response inhibition in all children. The heart rate of all children was increased in the two conditions of reward and reward/response cost. Study 2 revealed that children with ADHD-I responded more slowly and showed increased reaction time variability compared to both other groups. The present study supports an executive rather than a motivational deficit in the response inhibition among children with ADHD-C, though further results also indicate the role of auditory feedback on response inhibition. Additionally, the findings support the differentiation of ADHD-C and ADHD-I, suggesting that ADHD-I children are characterized by a sluggish cognitive tempo.     

Valence specific response reversal deficits and risk for mania

Response reversal deficits are well documented in bipolar disorder (BD). Although frequently construed as an index of reward processing abnormalities, these response reversal deficits might simply result from more general cognitive inflexibility. Given that both are implicated in BD, our goal was to more carefully test whether reversal learning deficits are specific to reward processing or reflect more general cognitive inflexibility. To more carefully assess deficits, a novel variant of the response reversal task was used to separate responses to in reward versus punishment feedback. In addition, while response reversal deficits are well documented in BD, it is still unknown if these deficits are observable in people at risk for the disorder, whose performance would be unconfounded by medication use and illness course. To assess the presence of premorbid response reversal deficits, we tested students at risk for developing BD, as defined by the well-validated Hypomanic Personality Scale. Undergraduates (n?=?99) were randomly assigned to complete either a reward only or a punishment only version of a response reversal task. Mania risk was related to difficulty reversing responses following reward, but not punishment feedback. Findings suggest that a deficit in response reversal may be an index of reward dysregulation in BD, and that this deficit can be observed even in those at high risk for the development of BD.     

Underlying processes in the poor response inhibition of children with Attention-Deficit/Hyperactivity Disorder

This study evaluated the effects of reward, punishment, and reward + punishment on the impulsive responses of ADHD children. The impulsive responses of ADHD and normal control boys (30 per group) were compared during performance of a go/no-go task, administered under reward-only, punishment-only, and reward + punishment conditions. When differences in aggression, anxiety, and IQ between these groups were controlled for, results indicated that the impulsivity levels of the ADHD group were higher than the control group in all three reinforcement conditions. Also, the ADHD group was more impulsive in the reward + punishment condition, compared to the reward-only and punishment-only conditions, and there was no difference between the reward-only and punishment-only conditions. The control groups showed no difference across the three reinforcement conditions. These findings raise the possibility that the poor response inhibition of ADHD children may be related to both a generalized inhibitory deficit and a response modulation deficit.     

Manipulating affective state influences conditioned appetitive responses

Affective states influence how individuals process information and behave. Some theories predict emotional congruency effects (e.g. preferential processing of negative information in negative affective states). Emotional congruency should theoretically obstruct the learning of reward associations (appetitive learning) and their ability to guide behaviour under negative mood. Two studies tested the effects of the induction of a negative affective state on appetitive Pavlovian learning, in which neutral stimuli were associated with chocolate (Experiment 1) or alcohol (Experiment 2) rewards. In both experiments, participants showed enhanced approach tendencies towards predictors of reward after a negative relative to a positive performance feedback manipulation. This increase was related to a reduction in positive affect in Experiment 1 only. No effects of the manipulation on conditioned reward expectancies, craving, or consumption were observed. Overall, our findings support the idea of counter-regulation, rather than emotional congruency effects. Negative affective states might therefore serve as a vulnerability factor for addiction, through increasing conditioned approach tendencies.     

Rat hippocampus and memory for places of changing significance

Rats were tested once daily on a four-choice delayed match from sample task with a water reward. Each day the correct place changed, and a single exposure to it was provided on information trials. Lesions of the hippocampal formation that involved the fornix, or dorsal hippocampus bilaterally, produced a severe impairment in the performance of previously trained rats. By contrast, lesions of the ventral hippocampus did not preclude reacquisition of the place-memory task. Some otherwise impaired rats with fornical lesions were able to find the water when aided by nonplace cues that consistently signaled reward. Reducing the number of choices from four to two did not aid the impaired rats. Certain lesions of the hippocampal formation in the rat produce a deficit appropriately described as amnesia. The memory deficit is consistent with a role for the hippocampus in processing of place information and shows some parallels to the amnesia seen in persons with temporal lobe lesions.     

Effects of positive and negative feedback on behavior control in hyperactive and normal boys

The hypothesis that hyperactive boys have relatively less response to negative feedback than to positive feedback was studied. Sixteen hyperactive boys and 16 controls were compared on two tasks under different feedback conditions. Feedback conditions were no feedback, positive feedback, and negative feedback. Tasks were symbol encoding and correcting spelling words. Hyperactives and controls were compared in amount of time on-task and amount of work correctly completed. Hyperactives were on-task significantly more under conditions of negative feedback than under positive feedback, but negative feedback significantly increased errors on the spelling correction task. Controls were equally responsive to positive, negative, or no feedback. Hyperactives accomplished significantly less than controls on the coding task, but performed as well as controls on the spelling correction task, which was administered to each boy at his own level of spelling ability. The results imply that while consistent negative feedback can reduce off-task behavior for hyperactives, it can also decrease the accuracy of the work they are doing.This research was supported in part by U.S. Public Health Service Training Grant (in Biological Science) No. MH07081. This article is based on a dissertation presented to the Graduate School of Arts and Sciences of Washington University in partial fulfillment of the requirements for the Ph. D. degree. The assistance of Dr. John A. Stern in helping with the preparation of the dissertation is gratefully acknowledged. The generous assistance of Dr. Cynthia Janes in helping prepare this paper is appreciated. The dissertation is available from University Micro-films (Order No. 74-13, 799). The assistance of Ms. B. Talent and Ms. S. Weiner in making reliability checks is gratefully acknowledged.     

社会比较对合作任务结果评价的影响：来自ERP的证据

现实生活中人们通过社会比较获得对自身的认识。前人研究探讨了金钱收入的比较对个体结果评价的影响, 而非金钱的社会比较效应的神经加工机制尚不清楚。本研究分离比较和金钱收入, 使用双人合作的投骰子任务, 先呈现“>”或“<”代表两人点数大小的比较结果, 再呈现合作任务的输赢结果, 考察非金钱的社会比较对合作任务结果加工的影响, 记录任务表现的比较结果和最终合作任务结果的ERP数据。发现在任务表现比较结果阶段, FRN和P300对代表行为表现好坏的社会比较信息敏感, 呈现无金钱输赢提示的点数大小的比较结果时, 点数小于他人比大于他人诱发更大的FRN和更小的P300; 任务表现的比较结果对合作任务最终的金钱输赢结果的影响并没有反应在FRN上。这些表明, 对非金钱的社会比较信息的加工始于结果快速评价的早期阶段。     

Controlled processing and vigilance in hyperactivity: Time will tell

This paper reviews the concept of sustained attention, placing it within a theoretical framework in which deficits of attention are conceived of as deficits of controlled information processing. Two types of deficit of sustained attention are distinguished: perceptual sensitivity and perceptual criterion. These two deficits are linked to a model of human performance that links controlled processes to the energetic pools: arousal and activation. Perceptual sensitivity (d) deficits are said to reflect arousal deficiencies, especially when observed in the early period of a vigil. Perceptual criterion deficits are associated with the activation pool and the response criterion measure . Despite clear evidence of perceptual deficiency in the hyperactive children to a greater extent than in the control group, and that performance in d declined with time on task, a significant interaction failed to occur between group classification and time on task. Thus, the results failed to support the hypothesis of a sustained attention deficit in hyperactives, since if hyperactives have a sustained attention deficit, both d and should have shown a significantly greater decline in the hyperactive group than in the controls with time on task.The authors wish to thank L. Leertouwer for making the drawings. This research was supported by grants from the Netherlands Foundation for the Advancement of Pure Research (ZWO) and the Professor Duijker Fund.     

Order of partial and consistent reward,reward magnitude shift,and resistance to extinction

In a separate-phase runway experiment with rats, four schedules involving partial (P) and consistent (C) reward (CC, CP, PC, and PP) were crossed with three reward magnitude shift conditions (upshift, nonshift, and downshift). The data revealed three major findings: (a) Reward magnitude downshift generally led to rapid extinction; (b) consistent reward prior to partial reward (CP) resulted in slower extinction than the reverse order (PC) under conditions of reward magnitude shift (particularly downshift); and (c) the relative performance of PC and CP under conditions of reward magnitude shift was reversed from postshift to extinction. On the basis of these data it was suggested that processes not presently identified by reinforcement level theory and stimulus analyzer theory influence extinction following separate-phase acquisition. A modification of reward level theory was presented to provide an account of extinction performance following separate-phase reward reduction.     

Time Reproduction in Children With ADHD: Motivation Matters

The primary goal of this study was to examine whether children with ADHD have a true deficit in subjective time sense, or whether their impairment reflects a motivational deficit. Thirty children with ADHD and 30 matched control children completed two versions of a time reproduction paradigm (“Regular” and “Enhanced”) in which motivational level was manipulated by the addition of positive sham feedback and the prospect of earning a reward. A secondary goal was to investigate performance on measures of working memory and behavioural inhibition, and how those constructs relate to time reproduction in the context of Barkley’s (1997a) model of ADHD. Children with ADHD performed significantly better on the motivating ‘Enhanced’ versus the Regular time reproduction paradigm, although they continued to perform significantly worse than controls on both tasks. Control children exhibited no reliable change in performance between versions of the task. Significant group differences were also observed on the working memory and behavioural inhibition tasks. We discuss the impact of motivation, working memory, and behavioural inhibition on time reproduction performance.     

Time reproduction in children with ADHD: motivation matters.

The primary goal of this study was to examine whether children with ADHD have a true deficit in subjective time sense, or whether their impairment reflects a motivational deficit. Thirty children with ADHD and 30 matched control children completed two versions of a time reproduction paradigm ("Regular" and "Enhanced") in which motivational level was manipulated by the addition of positive sham feedback and the prospect of earning a reward. A secondary goal was to investigate performance on measures of working memory and behavioural inhibition, and how those constructs relate to time reproduction in the context of Barkley's (1997a) model of ADHD. Children with ADHD performed significantly better on the motivating 'Enhanced' versus the Regular time reproduction paradigm, although they continued to perform significantly worse than controls on both tasks. Control children exhibited no reliable change in performance between versions of the task. Significant group differences were also observed on the working memory and behavioural inhibition tasks. We discuss the impact of motivation, working memory, and behavioural inhibition on time reproduction performance.     

A process analysis of the effects of performance-contingent rewards on intrinsic motivation

In this study, the effects of performance-contingent rewards on intrinsic motivation were examined in comparison to no-reward controls receiving identical performance feedback. A path analytic process analysis was conducted to examine the mediation of reward effects on subsequent task interest. It was hypothesized that competence valuation, or the personal importance of doing well, would be an important mediator of interest in situations where performance feedback was available. Rewards were predicted to affect interest by influencing an individual's valuation of competence, and by altering the competence valuation mediation process. In addition, achievement orientation was hypothesized to interact with reward in affecting importance and the mediation process. Prior to performing an interesting puzzle, high school students were offered a performance-contingent reward, and then indicated how personally important it was to do well. After doing three puzzles, all subjects received positive feedback regarding their performance. Multiple regression analyses indicated that importance was affected by the experimental variables, and had a positive causal impact on subsequent intrinsic motivation. It was found that the promise of performance-contingent reward positively affected importance for low achievers relative to high achievers, and that the mediation of subsequent intrinsic interest by importance differed according to reward by achievement combinations. Additionally, a direct effect revealed that performance-contingent rewards significantly enhanced interest, relative to no-reward controls receiving identical performance feedback.     

Impaired reward processing by anterior cingulate cortex in children with attention deficit hyperactivity disorder

Decades of research have examined the neurocognitive mechanisms of cognitive control, but the motivational factors underlying task selection and performance remain to be elucidated. We recently proposed that anterior cingulate cortex (ACC) utilizes reward prediction error signals carried by the midbrain dopamine system to learn the value of tasks according to the principles of hierarchical reinforcement learning. According to this position, disruption of the ACC–dopamine interface can disrupt the selection and execution of extended, task-related behaviors. To investigate this issue, we recorded the event-related brain potential (ERP) from children with attention deficit hyperactivity disorder (ADHD), which is strongly associated with ACC–dopamine dysfunction, and from typically developing children while they navigated a simple “virtual T-maze” to find rewards. Depending on the condition, the feedback stimuli on each trial indicated that the children earned or failed to earn either money or points. We found that the reward positivity, an ERP component proposed to index the impact of dopamine-related reward signals on ACC, was significantly larger with money feedback than with points feedback for the children with ADHD, but not for the typically developing children. These results suggest that disruption of the ACC–dopamine interface may underlie the impairments in motivational control observed in childhood ADHD.     

Lack of inhibition: a motivational deficit in children with attention deficit/hyperactivity disorder and children with traumatic brain injury.

Recent research has demonstrated that both brain-injured children and children with attention deficit/hyperactivity disorder (ADHD) suffer from response inhibition deficits. To investigate whether these deficits can be influenced by motivational factors, the stop-signal task was performed with and without reward contingencies for successful inhibition. Three groups of children between 8 and 12 years of age, participated in the study: 31 children with ADHD, 37 with traumatic brain injuries (TBI), and 26 normal controls. Results indicated that, although all groups showed comparable learning effects, reward contingencies had different effects on the groups. Whereas the performance of children with ADHD under reward contingencies were brought up to the performance level of normal controls, rewards were found less effective at improving response inhibition in children with TBI. The results further support a motivational/energetic explanation of the inhibitory deficit in children with ADHD, and of a primary response inhibition deficit due to structural brain damage in children with TBI.     

Lack of Inhibition: A Motivational Deficit in Children With Attention Deficit/Hyperactivity Disorder and Children With Traumatic Brain Injury*

Recent research has demonstrated that both brain-injured children and children with attention deficit/hyperactivity disorder (ADHD) suffer from response inhibition deficits. To investigate whether these deficits can be influenced by motivational factors, the stop-signal task was performed with and without reward contingencies for successful inhibition. Three groups of children between 8 and 12 years of age, participated in the study: 31 children with ADHD, 37 with traumatic brain injuries (TBI), and 26 normal controls. Results indicated that, although all groups showed comparable learning effects, reward contingencies had different effects on the groups. Whereas the performance of children with ADHD under reward contingencies were brought up to the performance level of normal controls, rewards were found less effective at improving response inhibition in children with TBI. The results further support a motivational/energetic explanation of the inhibitory deficit in children with ADHD, and of a primary response inhibition deficit due to structural brain damage in children with TBI.