Cooperative vocal control in marmoset monkeys via vocal feedback.
Humans adjust speech amplitude as a function of distance from a listener; we do so in a manner that would compensate for such distance. This ability is presumed to be the product of high-level sociocognitive skills. Nonhuman primates are thought to lack such socially related flexibility in vocal production. Using predictions from a simple arousal-based model whereby vocal feedback from a conspecific modulates the drive to produce a vocalization, we tested whether another primate exhibits this type of cooperative vocal control. We conducted a playback experiment with marmoset monkeys and simulated "far-away" and "nearby" conspecifics using contact calls that differed in sound intensity. We found that marmoset monkeys increased the amplitude of their contact calls and produced such calls with shorter response latencies toward more distant conspecifics. The same was not true in response to changing levels of background noise. To account for how simulated conspecific distance can change both the amplitude and timing of vocal responses, we developed a model that incorporates dynamic interactions between the auditory system and limbic "drive" systems. Overall, our data show that, like humans, marmoset monkeys cooperatively control the acoustics of their vocalizations according to changes in listener distance, increasing the likelihood that a conspecific will hear their call. However, we propose that such cooperative vocal control is a system property that does not necessitate any particularly advanced sociocognitive skill. At least in marmosets, this vocal control can be parsimoniously explained by the regulation of arousal states across two interacting individuals via vocal feedback.
Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey; Department of Psychology, Princeton University, Princeton, New Jersey; and.
Jung Yoon
JY
Choi
Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey; Department of Psychology, Princeton University, Princeton, New Jersey; and.
Daniel Y
DY
Takahashi
Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey; Department of Psychology, Princeton University, Princeton, New Jersey; and Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey asifg@princeton.edu.
Asif A
AA
Ghazanfar
D000161:Acoustic Stimulation / Q000379:methods; D000162:Acoustics; D000818:Animals; D001307:Auditory Perception; D002144:Callithrix / Q000523:psychology*; D025461:Feedback, Physiological; D030141:Feedback, Psychological; D008297:Male; D008954:Models, Biological; D009622:Noise; D011581:Psychological Tests; D012919:Social Behavior; D013017:Sound Localization; D013997:Time Factors; D014828:Vocalization, Animal
arousal; auditory cortex; cingulate; primate vocalizations