Social relationship affects neuronal responses of zebra finches differently for contact calls and aggressive encounter calls

In the social context, animal species depend on vocal communication throughout their life, as they are the primary source of communication, yet the neurophysiological underpinnings of the perception of intra-specific communication signals are still poorly understood. The brain processes underpinning the capacity to discern between familiar and unfamiliar vocalizations is still in infancy among avian species. Previous studies have demonstrated that zebra finch neurons in the secondary auditory cortex (caudomedial nidopallium or NCM) respond differently to distant calls from familiar conspecifics compared to those from unfamiliar conspecifics. In this study, we investigated the neural responses to contact calls and aggressive encounter calls from familiar and unfamiliar conspecifics in both primary and secondary avian auditory cortex. We use a neural response dataset of anesthetized zebra finches listening to the entire repertoire of vocalizations used by this species. Communication sounds were categorized into nine calls (Wsst, Distress, Thuck, Song, Distance, Tet, Nest, Long-tonal and Begging call) based on their behavioral significance, and brain responses were recorded using two electrode arrays in each hemisphere of six anaesthetized zebra finches. We hypothesize that this difference in magnitude of response between familiar and unfamiliar birds will not be as apparent for aggression/distress calls because contact calls bear strong individual signatures while calls during aggressive encounters are less individualized.