Cardiovascular mechanisms underlying vocal behavior in freely moving macaque monkeys

Abstract

Summary Communication is a keystone of animal behavior. However, the physiological states underlying natural vocal signaling are still largely unknown. In this study, we investigated the correlation of affective vocal utterances with concomitant cardiorespiratory mechanisms. We telemetrically recorded electrocardiography, blood pressure, and physical activity in six freely moving and interacting cynomolgus monkeys ( Macaca fascicularis ). Our results demonstrate that vocal onsets are strengthened during states of sympathetic activation, and are phase locked to a slower Mayer wave and a faster heart rate signal at ∼2.5 Hz. Vocalizations are coupled with a distinct peri-vocal physiological signature based on which we were able to predict the onset of vocal output using three machine learning classification models. These findings emphasize the role of cardiorespiratory mechanisms correlated with vocal onsets to optimize arousal levels and minimize energy expenditure during natural vocal production.

Linguistic law-like compression strategies emerge to maximize coding efficiency in marmoset vocal communication

“…Furthermore, they have been shown to be capable of adaptively modifying distinct call features, such as call frequency, amplitude and duration, in response to external acoustical stimuli [23][24][25]. Recently, it has been revealed that marmosets exhibit synchronized and phase-locked phono-articulatory movements suggesting that such speech-like bi-motor oscillations, which are crucial for speech production, evolved early in the primate lineage [26]. While we cannot go back in time to observe evolution, we can recreate scenarios with selective pressures to find out how vocal systems adapt [1].…”