Washington, May 21 : Depressed people are particularly sensitive to losses, and now researchers have found that the same may be true for mice.
Therefore, the scientists at Bristol University Veterinary School developed a new approach to measure animal emotional states based on findings from human psychology that emotions affect information processing.
Many studies have demonstrated beneficial welfare effects of enriched compared to barren housing, and the researchers found that rats housed in standard conditions, previously shown to experience poorer welfare than those housed in enriched conditions, were indeed more sensitive to the unanticipated loss of a food reward.
Oliver Burman, Richard Parker, Liz Paul and Mike Mendl from the Centre for Behavioural Biology at Bristol University consider the research indicates that sensitivity to reward reduction may be a valuable new indicator of animal emotion and welfare.
"The study of animal emotion is an important emerging field in subjects ranging from neuroscience to animal welfare research. Whilst we cannot know for sure what other animals feel, our approach may provide improved methods for indirectly measuring animal emotion and welfare," said Professor Mendl.
Dr Burman further explained, "Parallel studies using this approach in humans and animals may also reveal cross-species commonalities in the influence of affect on reward evaluation. Our next step is to see whether other reward evaluation processes involving contrasts between expected and actual rewards also reflect background emotional state."
The study is published in this week's issue of Royal Society Biology Letters.