The aim of this PhD thesis was to investigate the role of arousal during decision-making in chickens. Arousal can occur at various stages of the decision-making process and can have different functions depending on the stage and nature of the decision. A T-Maze methodology was developed for measuring behavioural and physiological indicators of arousal in chickens during a simple decision-making task. Measures of arousal were detectable during a goal viewing period and were differentiated by choice outcome. There was some evidence to suggest that arousal preceded and influenced decision-making, which provided a foundation for investigating arousal during more complex tasks. In two subsequent experiments indicators of arousal were measured when chickens made decisions that varied in their complexity i.e. decisions that were finely balanced and decisions involving the risk of an aversive stimulus. Arousal was not influenced by these aspects of complexity when chickens viewed their options, but did increase in anticipation of the decision outcome that was associated with the risk of an aversive stimulus. Interestingly, there was no evidence to suggest that arousal served to "warn" individuals against subsequently choosing the risky option, as has been suggested in human gambling tasks (using somatic markers). The role of arousal during the formation of expectations was also investigated in two reward alteration experiments. Arousal was gradually adjusted when chickens' expected rewards were unexpectedly altered. This suggests that chickens respond to a reward alteration following the Thorndikian law of effect, rather than by showing successive negative contrast effects. The methods developed and results obtained, provide a platform for investigating arousal during various stages of decision- making, including the role of somatic markers in guiding decision-making in non-human animals.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:685917 |
| Date | January 2015 |
| Creators | Davies, Anna Clare |
| Publisher | University of Bristol |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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