Sensory context gates oxytocin effects on auditory processing in macaques

Oxytocin shapes social perception, yet its neural effects vary substantially across experiments and clinical trials yield inconsistent results. A key unresolved question is whether oxytocin modulates early sensory processing in primates as a function of sensory context. Using high-resolution pharmacological fMRI in two awake rhesus macaques, we compared systemic oxytocin with saline during unimodal auditory and audiovisual tasks. During unimodal auditory stimulation, oxytocin attenuated sound-evoked responses throughout auditory core, belt and associative regions for both vocal and non-vocal sounds, while distributed sound-category information remained decodable. In contrast, when the same vocalizations were presented within an audiovisual task, this attenuation disappeared and responses increased in a restricted set of auditory core and belt regions. Oxytocin also reorganized resting-state coupling among auditory, visual and prefrontal systems and changed how evoked responses covaried across runs. Together, these findings suggest that oxytocin modulates sensory response magnitude and inter-regional coordination in a context-dependent manner rather than uniformly enhancing social signals.