Temperature asymmetries in facial areas as indicators of affective state in dairy calves and horses

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)

Abstract

The study of emotions in the animal welfare field is essential to increase the understanding of the way animals might perceive and react to different situations and how modifications in the way they are kept may improve their quality of life. In the field of animal studies, several methods looking at physiological, behavioural and cognitive elements of emotion had been developed, but some of them with particular limitations, including the need for laboratory or clinical facilities, their invasivity, subjective interpretation or lack of standardisation for the results. For these reasons, the development of new methods that allow the non-invasive measurement of objective indicators of animal emotion is required. The current dissertation aims to identify the potential of measuring temperature asymmetries as an indicator of emotional valence using infrared thermography as a non-invasive tool. To help achieve this aim, emotions have been categorised in terms of emotional valence (positive or negative) and emotional arousal (high or low). To explain how emotions are processed in the brain a lateralised processing has been hypothesised, i.e. left hemisphere for positive and right hemisphere for negative emotions, and a relationship between the activity of the brain hemispheres and temperature asymmetries in different Regions of Interest (ROIs) has been suggested (difference between temperatures in left and right sides in bilateral areas, like the eyes, nostrils, ears and skin covering the nasal airways). For this purpose, a series of studies in dairy calves and horses looking at situations likely to elicit negative (hot-iron disbudding and separation from the mother in calves) and positive affective responses (rewarding food in horses) were carried out, yielding some interesting results, suggesting a relationship between the direction of the temperature asymmetries in some ROIs and the valence of the emotion elicited in such circumstances, and highlighting the potential of infrared thermography for the study of animal emotions.
Date of Award28 Sep 2021
Original languageEnglish
Awarding Institution
  • The University of Bristol
SponsorsCONACyT
SupervisorMichael T Mendl (Supervisor), Suzanne D E Held (Supervisor), Sarah L Lambton (Supervisor), Helena H Telkanranta (Supervisor) & Becky Whay (Supervisor)

Keywords

  • INFRARED THERMOGRAPHY
  • COWS
  • CATTLE
  • EMOTIONS
  • TEMPERATURE ASYMMETRIES
  • BRAIN LATERALISATION
  • HORSES
  • CALVES
  • SEPARATION FROM THE MOTHER
  • HOT-IRON DISBUDDING

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