Ultrasonic vocalizations of around 50 kHz are emitted extensively during the play fighting of rats, reflecting a positive affective state. Some of these calls are associated with facilitating playóat an emotional level they appear to promote the playful mood of both the emitter and the recipient and at a tactical level they appear to coordinate playful contact and promote cooperative actions. The tactical role of these calls in averting escalation to serious fighting becomes more critical when adult rats engage in play. The experience of play fighting in the juvenile period promotes the development of social skills and does so, in part, by increasing the role of the prefrontal cortex in regulating social actions. There is emerging evidence that the experience of the diverse communicatory uses of 50-kHz calls during juvenile play may similarly facilitate the development of nuanced communicatory skills. © 2018 Elsevier B.V.
50-kHz Vocalizations, Play and the Development of Social Competence
