Kerstin Konrad

Reward System Dysfunction in Autism Spectrum Disorders

Although it has been suggested that social deficits of autism spectrum disorders (ASDs) are related to reward circuitry dysfunction, very little is known about the neural reward mechanisms in ASD. In the current functional magnetic resonance imaging study, we investigated brain activations in response to both social and monetary reward in a group of children with ASD, relative to matched controls. Participants with ASD showed the expected hypoactivation in the mesocorticolimbic circuitry in response to both reward types. In particular, diminished activation in the nucleus accumbens was observed when money, but not when social reward, was at stake, whereas the amygdala and anterior cingulate cortex were hypoactivated within the ASD group in response to both rewards. These data indicate that the reward circuitry is compromised in ASD in social as well as in non-social, i.e. monetary conditions, which likely contributes to atypical motivated behaviour. Taken together, with incentives used in this study sample, there is evidence for a general reward dysfunction in ASD. However, more ecologically valid social reward paradigms are needed to fully understand, whether there is any domain specificity to the reward deficit that appears evident in ASD, which would be most consistent with the ASD social phenotype.

Der Einfluss sozialer und monet?rer Belohnungen auf die Inhibitionsf?higkeit von Jungen mit hyperkinetischer St?rung des Sozialverhaltens

OBJECTIVE Social reinforcement can improve inhibitory control in boys with attention deficit/hyperactivity disorder (ADHD), suggesting that hyperkinetic conduct disorder (ADHD + CD/ODD), a combination of ADHD and conduct disorder (CD)/oppositional defiant disorder (ODD), might show similar improvements. This study investigated the effects of social and monetary reward on response inhibition in boys with ADHD + CD/ODD compared to healthy controls. METHOD An incentive go/no-go task was applied. We hypothesized that the control group (n = 17) would show greater improvements in inhibitory control in response to social reward than the ADHD + CD/ODD group (n = 17), but that both groups would respond equally to monetary reward. RESULTS Both groups showed improved inhibition accuracy in the social condition and even greater improvement in the monetary condition. Interestingly, the control group altered their response strategy when money was at stake, i.e., they slowed down more dramatically in favour of stronger inhibitory control and, thus, a potentially greater financial gain. CONCLUSIONS Our findings do not provide evidence for hyporesponsivity to social rewards in boys with ADHD + CD/ODD. Rather, our data suggest that both social and nonsocial reward procedures can be effective in behavioral interventions, but that monetary reinforcers may be more effective.

Störungen des Sozialverhaltens

The last few years have seen much research on girls with conduct disorder (CD). This article summarizes the gender-specific data regarding prevalence, differences with respect to symptomatology (e.g., subtypes of aggression, callous-unemotional (cu)-traits), and it presents data on the autonomic and neuroendocrine stress system as well as genetic, neurocognitive, and neuroimaging data. Differences in the impact of environmental factors on boys and girls for the development of CD are discussed. Taken together, the data indicate that there is great overlap in symptomatology, personality traits, and neurobiological aberrations in girls and boys with CD. Since fewer girls than boys exhibit CD symptomatology, further investigations on CD in girls might help to identify resilience factors that could improve future therapeutic interventions.