The role of dopamine and oxytocin in individual and social performance monitoring

Researchers have started to unravel the neurochemistry involved in performance
monitoring, which is the ability to detect our errors and act upon them, and in
social behaviour. Recently, we demonstrated that administration of the
neuropeptide oxytocin enhances processing of social mistakes, suggested to
derive from oxytocin-induced changes in perceived responsibility. Other
research employing pharmacological manipulations from our and other labs has
repeatedly established a crucial role for the neurotransmitter dopamine in
non-social performance monitoring. Yet, the role of dopamine in performance
monitoring in a social context remains unclear. Such insights are important
because recent theoretical accounts and animal studies have indicated that both
oxytocin and dopamine are involved in socially relevant processes, such as
reward processing and that especially the crosstalk between the two is
essential for facilitating positive social interactions. Pharmacological
studies directly comparing the effects of oxytocin and dopamine on social
performance monitoring in humans, however, are crucially missing.

The aim of this study is to improve our understanding of the mechanisms
underlying altered social performance monitoring from a pharmacological
perspective by directly comparing the effects of dopamine and oxytocin on
individual and social performance monitoring.

The study will employ a double-blind placebo-controlled cross-over design.

Oxytocin, L-DOPA, or placebo will be administered in randomized order over the
course of three sessions. After administration, resting state and structural
scans will be made and participants will perform three computerized tasks in
the magnetic resonance imaging (MRI) scanner: the Cannonball task, the
Prosocial Probabilistic Learning task and the Working Memory task.

There are no known risks associated with participating in fMRI studies. fMRI is
a non-invasive technique and numerous adults have undergone MRI studies without
apparent harmful consequences. Some people become claustrophobic while inside
the magnet and in these cases the study will be terminated immediately at the
participant's request. The only absolute contraindications to MRI studies are
metal implants, intraocular metal and heart arrhythmia. Relative
contraindications include claustrophobia. Subjects who may have metallic
foreign bodies in the eyes or head, or who have cardiac pacemakers will be
excluded. There are no known risk associated with the single administration of
intranasal oxytocin and L-DOPA in healthy volunteers. Protocols that employed
the same dosages of L-DOPA and oxytocin administration in healthy volunteers
have been previously approved by the CME of the LUMC (see e.g., P15.116;
P11.200). Although there is no direct benefit, the proposed research is
expected to make a significant contribution to our understanding of the
neurochemical mechanisms of individual and social performance monitoring,
processes that are of critical importance for safe, flexible and adaptive
(social) behaviour.