Using judgement bias to measure positive affective state in dogs
Publication Type: |
Journal Article |
Year of Publication: |
2011 |
Authors: |
Oliver Burman, Ragen McGowan, Michael Mendl, Yezica Norling, Elizabeth Paul, Therese Rehn, Linda Keeling |
Publication/Journal: |
Applied Animal Behaviour Science |
Keywords: |
animal welfare, cognition, dogs, positive affect |
ISBN: |
0168-1591 |
Abstract:
Interest in the induction and measurement of positive affective states in non-human animals is increasing. Here, we used a test of cognitive (judgement) bias, based on the finding that individuals experiencing different affective states judge ambiguous stimuli differently, to measure whether a positive low arousal affective state (e.g. [`]satisfaction’/[`]contentment’) could be induced in domestic dogs as a result of their experiencing a food-based rewarding event. In this rewarding event, subjects (1 year old female Beagles) had to search for small amounts of food randomly placed within a maze arena. Using a balanced within-subjects design, the dogs (N = 12) received a cognitive bias test either without experiencing the rewarding event (the [`]Neutral’ treatment), or directly after experiencing the rewarding event (the [`]Post-consumption’ treatment). In the test, dogs were trained that one visual cue (e.g. dark grey card) predicted a positive event (food in a bowl) whilst a different cue (e.g. light grey card) predicted a relatively [`]negative’ event (empty bowl). We hypothesised that dogs tested after experiencing the rewarding event, and in a presumed post-consummatory positive affective state, would be more likely to judge visually ambiguous stimuli (intermediate grey cards) positively, compared to dogs in the [`]Neutral’ treatment. In contrast, we found that they took significantly longer to approach an intermediate ambiguous stimulus, suggesting that they were less likely to anticipate food (a negative judgement) compared to dogs in the [`]Neutral’ treatment group. Various explanations for the observed results are discussed, in particular how reward acquisition and consumption may influence positive affective state induction in animals.