Oxytocin (OT) enhances social behaviors such as attachment and parental caretaking. Neural correlates of maternal attachment are found in reward-related brain regions, for example, in the globus pallidus (GP). The present work investigates the effects of OT on the neural correlates of parental attachment. Fathers viewed pictures of their own child (oC), a familiar child (fC), and an unfamiliar child (uC) after intranasal application of OT vs placebo. OT reduced activation and functional connectivity of the left GP with reward- and attachment-related regions responsive to pictures of the oC and the uC. The present results emphasize the key role of OT in human parental attachment and suggest that OT reduces neural reactivity to social cues as a function of social salience. Our results together with previous findings speak to a selective reduction of neural reactivity to social stimuli, irrespective of their valence. We argue that one major pathway by which OT exerts its positive effects on affiliative and social behaviors is the attenuation of automatic neural responses, which in turn leads to increased approach behaviors and decreased social avoidance.

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Humans value rewards less when these are delivered in the future as opposed to immediately, a phenomenon referred to as delay discounting. While delay discounting has been studied during the anticipation of rewards and in the context of intertemporal decision-making, little is known about its neural correlates in the outcome phase (during reward delivery) and their relation to personality. Personality traits that have been associated with increased delay discounting include impulsivity and, potentially, anxious-depressive traits. Here we performed functional magnetic resonance imaging (fMRI) in 72 healthy participants while they carried out a monetary incentive delay (MID) task with a delay manipulation. In sixty percent of the experimental trials, participants won rewards that differed in magnitude (0.05€, 0.50€ or 1€) and delay until delivery (immediately, 10 days, or 100 days). A factor analysis on questionnaires yielded two factors reflecting Impulsivity and Anxiety/Depression, which we used to examine potential relationships between personality and delay discounting. When winning a reward, medial prefrontal cortex (mPFC) activation was higher for immediate compared to delayed rewards. Moreover, amygdala activation correlated with reward magnitude for immediate but not for delayed rewards. Amygdala activation to winning immediate rewards was higher in more impulsive participants, while mPFC activation to winning immediate rewards was higher in more anxious-depressed participants. Our results uncover neural correlates of delay discounting during reward delivery, and suggest that impulsivity and subclinical anxious-depressive traits are related to stronger neural responses for winning immediate relative to delayed rewards.