Grant: Discovery Grants Program - Individual

The most common form of play in non-human animals is ""rough-and-tumble"" play or ""play fighting"", which is a non-injurious form of competitive interaction, in which partners compete for some advantage over one another, such as being able to bite their partner gently. Behavioural mechanisms exist that reduce the risk of play fighting escalating into serious fighting; this makes the repeated bodily contact present in play rewarding. When animals, such as rats, are deprived, in the juvenile period, of the opportunity to engage in peer-peer play, they develop into socially incompetent adults. My work has shown that if certain areas of the brain are damaged, such as the prefrontal cortex, rats exhibit social deficits as if they had been deprived of play. Also, my laboratory has shown that the anatomy of the neurons of the prefrontal cortex is modified when varying the experiences of play that animals have had as juveniles. Therefore, I theorize that experience with play fighting as juveniles is necessary for the development of those areas of the brain that are critical for social competency. In the proposed research, I will use laboratory rats to investigate what aspects of the play experience are critical for the development of the brain and characterize the mechanisms by which a more competent social brain executes more competent social behaviour. For example, improved performance may arise from enhanced ability to sequence together complex movements or by attenuating the effects of fear arising from novel and unpredictable social contexts. I will also conduct a comparative analysis of play in a diverse range of primates to determine whether the organization of play fighting differs among species depending on the complexity of their social behaviour. Again, my preliminary findings suggest that those species with more complex problems to solve in their societies have patterns of play as juveniles that seem appropriate for training them to make quick and varied actions. These studies will characterize how social competence develops and the contribution made to this development by the experience of play as juveniles.