Effects of Oxytocin on Face Processing in Autism

Background:  Recent human research has focused on the behavioural significance of neuropeptides, such as arginin vasopressin and oxytocin. It has been shown, for example, that oxytocin suppresses behavioural and endocrine responses to social stress and increases trust. Regarding the role of oxytocin in autism spectrum disorders (ASD), a few studies have shown that genetic variations of the oxytocin receptor might play a role in the pathogenesis. In addition, beneficial effects of exogenously administered oxytocin on ASD symptoms have been reported.

Objectives: In recent years we have conducted a number of studies investigating the effects of oxytocin on the processing of social stimuli with the aim to elucidate the behavioural and neural underpinnings of the proposed prosocial effects in ASD.

Methods: We used intranasal administrations of single doses of 24 IU oxytocin in between- and within group designs to investigate the effects of exogenous oxytocin on performance in facial emotion recognition, face discrimination and facial attention tasks. In addition, functional magnetic resonance imaging was used to assess effects on regional brain activity as reflected by modulations of local blood-oxygen-level-dependent responses to the stimuli presented in these tasks.

Results: Using exogenous administration of oxytocin we could show that oxytocin increases emotion recognition, early stages of visual attention, and overt visual scanning for human faces in neurotypical controls. Data from functional magnetic resonance imaging studies show that on the neural level, oxytocin modulates the neural circuitry that specifically corresponds to the observed behavioural effects. In ASD, several brain regions known to be involved in social cognition (anterior insula, cuneus/precuneus, rostral anterior cingulate cortex, and temporal parietal junction) showed oxytocin-induced increased activity during the processing of facial stimuli, which was associated with improved emotion recognition. In another study, a single dose of oxytocin increased amygdala activity in response to neutral faces – an effect that was specific for participants with ASD.

Conclusions:  Oxytocin-induced facilitation of social attention and emotion recognition suggests that the intranasal administration of oxytocin might be a promising approach in the treatment of cognitive deficits in the social domain in ASD. However, the experimental studies so far underline the need for controlled clinical trials.