Unique cortical and subcortical activation patterns for different conspecific calls in marmosets

Abstract

The common marmoset (Callithrix jacchus) is known for its highly vocal nature, displaying a diverse range of different calls. Functional imaging in marmosets has shown that the processing of conspecific calls activates a brain network that includes fronto-temporal cortical and subcortical areas. It is currently unknown whether different call types activate the same or different networks. Here we show unique activation patterns for different calls. Nine adult marmosets were exposed to four common vocalizations (phee, chatter, trill, and twitter), and their brain responses were recorded using event-related fMRI at 9.4T. We found robust activations in the auditory cortices, encompassing core, belt, and parabelt regions, and in subcortical areas like the inferior colliculus, medial geniculate nucleus, and amygdala in response to these conspecific calls. Different neural activation patterns were observed among the vocalizations, suggesting vocalization-specific neural processing. Phee and twitter calls, often used over long distances, activated similar neural circuits, whereas trill and chatter, associated with closer social interactions, demonstrated a closer resemblance in their activation patterns. Our findings also indicate the involvement of the cerebellum and medial prefrontal cortex (mPFC) in distinguishing particular vocalizations from others. Significance StatementThis study investigates the neural processing of vocal communications in the common marmoset (Callithrix jacchus), a species with a diverse vocal repertoire. Utilizing event-related fMRI at 9.4T, we demonstrate that different marmoset calls (phee, chatter, trill, and twitter) elicit distinct activation patterns in the brain, challenging the notion of a uniform neural network for all vocalizations. Each call type distinctly engages various regions within the auditory cortices and subcortical areas, reflecting the complexity and context-specific nature of primate communication. These findings offer insights into the evolutionary mechanisms of primate vocal perception and provide a foundation for understanding the origins of human speech and language processing.