Oxytocin modulates neurocomputational mechanisms for learning social rank, boosting vmPFC and amygdala activity.

Understanding how humans learn and infer complex social hierarchies is crucial for comprehending social cognition. While the neural bases for linear social hierarchies are known, the mechanisms for learning more intricate rank relationships (e.g., <, =, >) within social networks remain elusive. Oxytocin (OXT), a neuropeptide known for its role in social affiliation, memory, and emotional regulation, has been implicated in modulating social dominance and memory. This study addresses the gap in understanding OXT's specific role in the neurocomputational processes of learning and retrieving complex social network ranks.

Researchers investigated oxytocin's modulatory role in human participants learning and inferring rank relationships within two social networks: one in which they were embedded (self-oriented) and one external (other-oriented). Participants were administered either oxytocin or placebo. During a training phase, they learned rank relationships between network members. A subsequent test phase required them to infer relationships between previously unencountered pairs. Brain activity was monitored, likely using fMRI, to identify neural correlates of learning and memory retrieval, with choice accuracy as a primary behavioral endpoint.

During the training phase, oxytocin (vs. placebo) significantly improved choice accuracy when participants learned rank relationships in the other-oriented network. This improvement was accompanied by increased activity in the ventromedial prefrontal cortex (vmPFC). During the subsequent test phase, oxytocin modulated the balance between self- and other-oriented social memory. Specifically, it boosted performance and amygdala responses for memory retrieval concerning social networks in which participants were not embedded. These findings highlight a reference-frame dependent modulation by oxytocin. While specific quantitative data like p-values or effect sizes were not provided in the abstract, the qualitative improvements were consistently reported across behavioral and neural measures.

Oxytocin improved choice accuracy for other-oriented social networks during learning and boosted performance for other-oriented memory retrieval during inference, increasing vmPFC and amygdala activity respectively.