
Title: Social discrimination and memory in pigs and rats
Author: Jones, Samantha Mary
ISNI:       0000 0004 2725 4799
Awarding Body: University of Bristol
Current Institution: University of Bristol
Date of Award: 2011
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Although positrve social relationships can enrich the lives of animals, aggression, intimidation and socially induced stress can cause serious welfare problems. It is therefore important to try to understand how animals remember other individuals, and past social encounters. The main aim of the experimental research was to determine whether pigs and rats can discriminate between conspecifics using social categories such as 'familiar/unfamiliar' and 'group-mate/non-group-mate'. Once a reliable technique had been established, it could then be used to investigate their social memory, specifically how long it takes for an animal to move from one category to another and how long a memory of an animal as 'familiar' lasts. Methods were first developed to assess whether rats could discriminate between group- mate and non-group-mate stimuli. In Experiment One, an operant lever-pressing task was used to determine if rats could discriminate between group-mates and non-group-mates. In Experiment Two their spontaneous behavioural response to home-cage and non-home-cage odours was assessed. An operant digging task was then employed to assess the rats' ability to discriminate between odours collected from individual group-mate and non-group-mate animals (Experiment Three) and investigate the duration of social memory for previous group-mates (Experiment Four). Operant techniques were then developed to assess whether pigs were able to discriminate between individual group-mate and non-group-mate animals, first using a symmetrical reinforcement paradigm (Experiment Five) similar to Experiment One, and then using a Y- maze approach (Experiment Six). Overall, operant tasks employing responses in the animals' natural behavioural repertoire (Experiments Three, Four and Six) proved more successful than the more abstract methods used in Experiments One and Five. Both species were able to successfully discriminate between 'group-mate' and 'non-group-mate' stimuli and showed evidence of developing cognitive categories. However, more research is needed to determine the processes involved in social discrimination and how long a memory may last.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available