Der Effekt von Belohnungen auf die intraindividuelle Variabilität der Reaktionszeit bei erwachsenen ADHS-Patienten : eine Analyse anhand des Ex-Gauß’schen Verteilungsmodells

Mapping Intimacies ◽

10.21248/gups.64500 ◽

2021 ◽

Author(s):

◽

Vera Christine Deppert

Keyword(s):

Reaction Time ◽

Adult Adhd ◽

Monetary Incentive ◽

Time Variability ◽

Healthy Controls ◽

Adhd Symptoms ◽

Reaction Time Variability ◽

Delay Task ◽

Monetary Incentive Delay Task ◽

Monetary Incentive Delay

Increased intraindividual variability of reaction time is a main cognitive feature of Attention Deficit Hyperactivity Disorder. It is associated with deficits in sustained attention. While traditionally, mean and variance were used to characterize reaction time distributions, the ex-gaussian distributional model allows a more sophisticated analysis of reaction time series. Reaction time distributions are separated in a normal and an exponential component. The present study investigates the impact of incentives on reaction time variability in a sample of adult ADHD patients. ADHD is associated with increased Tau, the output parameter of the ex-gaussian model characterizing the exponential part of the distribution. Tau is linked to “lapses of attention”, which are more frequent in ADHD patients. It is known that tau can be modulated in ADHD Patients. It was therefore postulated that tau would be higher in ADHD Patients in a paradigm where quick answers were required but could be modulated by monetary incentives. In addition, the effect of “delay discounting”, which is more distinct in ADHD patients, on reaction time variability was investigated. Eventually, the association of variability measures with strength of ADHD symptoms was tested. To this end, reaction time distributions of 62 adult ADHD patients and 45 healthy controls from two different reaction time paradigms were analyzed. The monetary incentive delay task, by comprehending a control – and a win condition, allows an investigation of the effect of incentives on reaction times. Subjects had to react as fast as possible by keypress to a stimulus, after a cue signaled a possible monetary reward. During the Delay-Discounting-Task, subjects had to choose between sooner, but smaller, and higher delayed monetary rewards, during which they could use as much time for consideration as desired. Results show that an increased Tau in the control condition of the monetary- incentive-delay-task could be replicated, while a distinct influence of the win condition emerged. Subjects with ADHD showed an improvement of Tau in the win condition even below the level of healthy controls. However, they showed increased variability of the “regular” responses around the mean of the normal component of the distribution, represented by sigma. Moreover, it was indicated by trend a higher reaction time variability in ADHD patients during choices of delayed rewards. Tau was associated the current symptom strength as well as with the strength of ADHD-Symptoms during childhood, assessed by questionnaire. While the present results could have implications for etiological models of the disease, they may also contribute to the development of novel diagnostic methods. In advanced studies, neural correlates of sophisticated measures of reaction time variability should be investigated. Furthermore, they should be associated with genetic risk factors with regard to possible endophenotypes. Possible implications for clinical handling of patients should be explored.

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Hyperactive/impulsive and inattention symptoms are associated with reduced ERP activity during different reward processing stages: Evidence from the electrophysiological Monetary Incentive Delay Task in adult ADHD

10.1101/817973 ◽

2019 ◽

Author(s):

M. P. Bennett ◽

H. Kiiski ◽

Z. Cao ◽

F. R. Farina ◽

R. Knight ◽

...

Keyword(s):

Visual Cues ◽

Adult Adhd ◽

Monetary Incentive ◽

Reward Processing ◽

Button Press ◽

Adhd Symptoms ◽

Symptom Dimensions ◽

Delay Task ◽

Monetary Incentive Delay Task ◽

Monetary Incentive Delay

AbstractHyperactivity/impulsivity and inattention are core symptoms dimensions in attention-deficit/hyperactivity disorder. Some approaches suggest that these symptoms arise from deficits in the ability to anticipate and process rewards. However, evidence is equivocal with regard to ADHD-related differences in brain activity during reward processing. The aim of this study was to investigate when, and how, reward-related ERP activity was associated with hyperactive/impulsive symptoms and inattention symptoms. Adults with ADHD (n=34) and matched comparison participants (n=36) completed an electrophysiological version of the Monetary Incentive Delay task. This task separates reward processing into two stages-namely, an anticipation stage and a delivery stage. During the anticipation stage, visual cues signalled a possible monetary incentive (i.e. a reward or loss). After a brief delay, the delivery stage began, and incentives were delivered contingent on a speeded button-press. Electroencephalogram activity was simultaneously sampled and incentive-related event relate potentials (ERPs) calculated. These data were then analysed by calculating multiple regression models, at each sample point, wherein the correlation between incentive-related ERPs and ADHD symptoms was estimated. Linear and curvilinear associations between ERP activity and ADHD symptoms were tested in each regression mode. Findings suggest that ADHD symptoms were associated ERP activity at different reward processing stages. Hyperactive/impulsive symptoms were associated with reduced ERP activity during the initial anticipation of rewards from 224-329 ms post-reward cue. Inattention symptoms were associated with reduced ERP activity during the initial delivery of rewards from 251-280 ms post-reward onset. Finally, extreme ends of hyperactive/impulsive and inattention symptoms were associated with reduced ERP activity towards the end of the anticipation stage from 500 ms post-reward cue onwards. These results support the idea that reward processing is disrupted in ADHD while also shedding new light on the dynamic relationship between ADHD symptom dimensions and the neurological mechanisms of reward processing.

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Loss anticipation and outcome during the Monetary Incentive Delay Task: a neuroimaging systematic review and meta-analysis

PeerJ ◽

10.7717/peerj.4749 ◽

2018 ◽

Vol 6 ◽

pp. e4749 ◽

Cited By ~ 13

Author(s):

Jules R. Dugré ◽

Alexandre Dumais ◽

Nathalie Bitar ◽

Stéphane Potvin

Keyword(s):

Meta Analysis ◽

Monetary Incentive ◽

Anterior Insula ◽

Anterior Cingulate ◽

Healthy Controls ◽

Imaging Studies ◽

Delay Task ◽

Monetary Incentive Delay Task ◽

Monetary Incentive Delay ◽

Neuro Imaging

Background Reward seeking and avoidance of punishment are key motivational processes. Brain-imaging studies often use the Monetary Incentive Delay Task (MIDT) to evaluate motivational processes involved in maladaptive behavior. Although the bulk of research has been done on the MIDT reward events, little is known about the neural basis of avoidance of punishment. Therefore, we conducted a meta-analysis of brain activations during anticipation and receipt of monetary losses in healthy controls. Methods All functional neuro-imaging studies using the MIDT in healthy controls were retrieved using PubMed, Google Scholar & EMBASE databases. Functional neuro-imaging data was analyzed using the Seed-based d Mapping Software. Results Thirty-five studies met the inclusion criteria, comprising 699 healthy adults. In both anticipation and loss outcome phases, participants showed large and robust activations in the bilateral striatum, (anterior) insula, and anterior cingulate gyrus relatively to Loss > Neutral contrast. Although relatively similar activation patterns were observed during the two event types, they differed in the pattern of prefrontal activations: ventro-lateral prefrontal activations were observed during loss anticipation, while medial prefrontal activations were observed during loss receipt. Discussion Considering that previous meta-analyses highlighted activations in the medial prefrontal cortex/anterior cingulate cortex, the anterior insula and the ventral striatum, the current meta-analysis highlighted the potential specificity of the ventro-lateral prefrontal regions, the median cingulate cortex and the amygdala in the loss events. Future studies can rely on these latter results to examine the neural correlates of loss processing in psychiatric populations characterized by harm avoidance or insensitivity to punishment.

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