Ellen Demurie

Common Alterations in Sensitivity to Type but Not Amount of Reward in ADHD and Autism Spectrum Disorders.

BACKGROUND Children with attention deficit/hyperactivity disorder (ADHD) display abnormalities in reward processing. Most reward studies have focused on the effects of material or monetary rewards. Studies with autism spectrum disorder (ASD) have focused on social rewards. In this study we compared the effects of amount and type of reward in children with ADHD and those with ASD. METHODS Two adapted versions of the Monetary Incentive Delay Task were used to study the effects of monetary and social reward anticipation on performance in 40 typically developing (TD) children and adolescents (8-16y), 35 children and adolescents with ADHD and 31 children and adolescents with ASD. RESULTS Monetary and social reward improved accuracy and response time (RT) in all groups. The higher the anticipated reward, the more accurate and faster were responses. Independent of these effects, there was a differential effect of reward type. Both clinical groups, but not TD, responded faster for monetary than social rewards. CONCLUSIONS The results, while not supporting hyposensitivity to changes in reward amount in ADHD and ASD, do suggest that both groups are generally less motivated in settings where social as opposed to monetary rewards can be earned.

Temporal discounting of monetary rewards in children and adolescents with ADHD and autism spectrum disorders

It has been difficult to differentiate attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in terms of some aspects of their cognitive profile. While both show deficits in executive functions, it has been suggested that they may differ in their response to monetary reward. For instance, children with ADHD prefer small immediate over large delayed rewards more than typically developing controls. One explanation for this is that they discount the value of rewards to a higher degree as they are moved into the future. The current study investigated whether children with ADHD can be differentiated from those with ASD in terms of reward discounting. Thirty-nine children (8-16 y) with ADHD, 34 children with ASD and 46 typically developing controls performed a hypothetical monetary temporal discounting task. Participants were instructed to make repeated choices between small variable rewards (0, 5, 10, 20, 30€) delivered immediately and large rewards delivered after a variable delay. Children with ADHD but not ASD discounted future rewards at a higher rate than typically developing controls. These data confirm steeper discounting of future rewards in ADHD and add to a small but growing literature showing that the psychological profile of ADHD can be distinguished from that of ASD in terms of disrupted motivational processes.

How impaired is mind-reading in high-functioning adolescents and adults with autism?

Difficulties in understanding the mental states of others are considered to be a core cognitive feature of autism spectrum disorders (ASD). Traditional false-belief tasks were not suitable to measure mind-reading in adolescents and adults with ASD and were replaced by so-called more “advanced” tasks. A first series of tasks included the presentation of static stimuli in the visual or auditory modality. More recently, more dynamic, naturalistic tasks were developed. The most ecologically valid task to measure mind-reading is probably the empathic accuracy paradigm. Research with advanced mind-reading tests has demonstrated that high-functioning adults with ASD should not be underestimated since they may have good and in some cases very good mind-reading skills. Impairments are most obvious when an unstructured, dynamic and naturalistic task is being used.

No Evidence for Inhibitory Deficits or Altered Reward Processing in ADHD Data From a New Integrated Monetary Incentive Delay Go/No-Go Task

Objective: Cognitive and motivational factors differentially affect individuals with mental health problems such as ADHD. Here we introduce a new task to disentangle the relative contribution of inhibitory control and reward anticipation on task performance in children with ADHD and/or autism spectrum disorders (ASD). Method: Typically developing children, children with ADHD,  ASD, or both disorders worked during separate sessions for monetary or social rewards in go/no-go tasks with varying inhibitory load levels. Participants also completed a monetary temporal discounting (TD) task. Results: As predicted, task performance was sensitive to both the effects of anticipated reward amount and inhibitory load. Reward amount had different effects depending on inhibitory load level. TD correlated with inhibitory control in the ADHD group. Conclusion: The integration of the monetary incentive delay and go/no-go paradigms was successful. Surprisingly, there was no evidence of inhibitory control deficits or altered reward anticipation in the clinical groups.

The effects of monetary and social rewards on task performance in children and adolescents: liking is not enough

The current study compared the effects of reward anticipation on task performance in children and adolescents (8–16 years old) using monetary and various social rewards. Eighty‐five typically developing children undertook the Monetary Incentive Delay (MID) task. Of these 44 also undertook the Social Incentive Delay (SID‐basic) task where social reward was operationalized as a smiling face and spoken compliments. Forty‐one children participated in the SID‐plus where points were added to a pictogram with written compliments. In a preparatory validation study participants were asked howmuch they liked the SID‐basic rewards.Results showed that there was an effect of reward size on accuracy and RT in both the MID task and SID‐plus, but not SID‐basic. Subjective value of the SID‐basic rewards was rated higher with hypothesized increasing reward intensity. In conclusion, although the social rewards in SID‐basic were liked by children andadolescents in the validation study, they had no effect on the behaviour. Only when points were added (SID‐plus), anticipated social reward affected task performance. Thus our results highlight (i) the difference between likeability andreinforcing quality and (ii) the need for a quantifiable element to rewards for themto be reinforcing for children. Copyright

The early development of infant siblings of children with autism spectrum disorder : characteristics of sibling interactions

Although sibling interactions play an important role in children’s early development, they are rarely studied in very young children with an older brother or sister with autism spectrum disorder (ASD). This study used a naturalistic, observational method to compare interactions between 18-month-old infants and their older sibling with ASD (n = 22) with a control group of 18-month-old infants and their typically developing (TD) older sibling (n = 29). In addition, role (a)symmetry and the influence of gender were evaluated. Sibling interactions in ASD-dyads were characterized by higher levels of negativity. Although somewhat less pronounced in ASD-dyads, role asymmetry was present in both groups, with the older child taking the dominant position. Finally, siblings pairs with an older sister were characterized by more positive behaviours. Since differences in sibling interactions may alter the developmental trajectories of both siblings, these early relationships should be taken into account in future ASD research and interventions.

Social Interactions Between 24-Month-Old Children and Their Older Sibling with Autism Spectrum Disorder: Characteristics and Association with Social-Communicative Development

This study compared sibling interactions between 24-month-old children and their older sibling with ASD (high-risk; n = 24) with 24-month-old children and their typically developing older sibling (low-risk; n = 32). First, high-risk sibling pairs showed lower levels of positive behaviour and younger siblings of children with ASD imitated their older sibling less. Second, in the high-risk group positive interactions were positively associated with the youngest child’s language abilities. However, this association was no longer significant after controlling for language abilities at 14 months. Third, more total interactions in the high-risk group, both negative and positive, were associated with more ASD characteristics. Thus, early sibling interactions might reveal interesting information in light of the (atypical) developmental trajectories of younger siblings of children with ASD.