Voice patches in the marmoset auditory cortex revealed by wide-field calcium imaging

Species-specific vocalizations are behaviorally critical sounds. Similar to faces, species-specific vocalizations are important for the survival and social interactions of both humans and vocal animals. Face patches have been found in the brains of both human and non-human primates. In humans, a voice patch system has been identified on the lateral superior temporal gurus (STG) that is selective to human voices over other sounds. In non-human primates, while vocalization-selective regions were found on the rostral portion of the temporal lobe outside of the auditory cortex in both macaques and marmosets using functional magnetic resonance imaging (fMRI), it is yet clear whether vocalization-selective regions are present in the auditory cortex. Using wide-field calcium imaging, a technique with both high temporal and high spatial resolution, we discovered two voice patches in the marmoset auditory cortex that preferentially respond to marmoset vocalizations over other sounds and carry call types and identity information. One patch is located on the posterior primary auditory cortex (A1), and the other one is located on the anterior non-core region of the auditory cortex. These voice patches are functionally connected and hierarchically organized as shown by latency and selectivity analyses. Our findings reveal the existence of voice patches in the auditory cortex of marmosets and support the notion that similar cortical architectures are adapted for recognizing communication signals for both vocalizations and faces in different primate species.