Insect sentience and the rise of a new inclusive ethics

Welfare protections for vertebrates are grounded in the belief that vertebrates are sentient and capable of feeling whereas invertebrates are not. We agree with Mikhalevich & Powell that the exclusion of small-brained invertebrates from bioethics is not warranted by the current state of the scientific evidence. The choice to promote protection for certain invertebrates should be based on the Animal Sentience Precautionary Principle (ASPP). This principle should not prevent us from conducting experimental research with non-human animals to advance knowledge. However, we believe that it is important to outline practical guidelines to manage the wellbeing of invertebrates, while accumulating further evidence on their inner life

Assessing emotions to improve animal welfare: the use of a multimodal approach

PhDThe broad concern to recognise animals as sentient beings motivates the identification and implementation of new strategies to promote positive affective states, especially in farm settings. The use of a multidimensional approach that takes into account different parameters, including vocalisations, physiological indices and cognition simultaneously, has been proved effective to assess emotions in non-human animals. This approach allows assessing the valance (pleasant vs unpleasant) and intensity (high or low) of the emotional experience. The first chapter of this thesis describes the rationale for using a multimodal approach to assess emotions in animals and its implication for animal welfare. The second chapter includes a detailed review of the impact of emotions on cognitive processes and has a special focus on farm animals. The third chapter presents a study testing the use of a judgement bias test to detect positive emotions following grooming in goats. Although a positive judgement bias has not been identified, the physiological data indicate that the grooming is effective in inducing positive emotional states. In the fourth chapter, the behavioural, physiological and vocalisation profile of goats trained to anticipate positive (palatable food) or negative outcomes (inaccessible food) is explored. Results suggest that goats perceive the positive condition differently from the negative and neutral conditions (i.e. more intense behavioural and physiological response). The fifth chapter provides evidence for the involvement of the left hemisphere when goats process conspecific and familiar calls produced in isolation and feeding conditions. The sixth chapter describes a study looking at the ability of goats to acoustically discriminate and respond to conspecific vocalisations with different emotional valence. Results suggest that goats are able to detect emotional changes in vocalisations and that the valence of the calls affect cardiac variability. Overall, the findings of these studies advance the understanding of the evolutionary function of emotions and have important implications for animal welfare

Goats distinguish between positive and negative emotion-linked vocalisations

Background Evidence from humans suggests that the expression of emotions can regulate social interactions and promote coordination within a group. Despite its evolutionary importance, social communication of emotions in non-human animals is still not well understood. Here, we combine behavioural and physiological measures, to determine if animals can distinguish between vocalisations linked to different emotional valences (positive and negative). Using a playback paradigm, goats were habituated to listen to a conspecific call associated with positive or negative valence (habituation phase) and were subsequently exposed to a variant of the same call type (contact call) associated with the opposite valence (dishabituation phase), followed by a final call randomly selected from the habituation phase as control (rehabituation phase). The effects of the calls on the occurrence of looking and cardiac responses in these phases were recorded and compared. Results We found that when the valence of the call variant changed, goats were more likely to look at the source of the sound, indicating that they could distinguish calls based on their valence. Heart rate was not affected by the valence of the calls played, whereas heart-rate variability tended to be higher in the habituation and rehabituation phases, when positive calls were played compared to negative ones. Together, the behavioural and physiological measures provide evidence suggesting, first, that goats are able to distinguish call variants based on their valence, and second, that goat behaviour and cardiac responses are affected by call valence. Conclusion This study indicates that auditory modalities are a potent means to communicate emotions in non-human animals. These findings can contribute to our understanding of the evolution of emotion perception in non-human animals.ISSN:1742-999

Perceptual lateralization of vocal stimuli in goats

Functional asymmetries, for example, the preferential involvement of 1 brain hemisphere to process stimuli, may increase brain efficiency and the capacity to carry out tasks simultaneously. We investigated which hemisphere was primarily involved in processing acoustic stimuli in goats using a head-orienting paradigm. Three playbacks using goat vocalizations recorded in different contexts: food anticipation (positive), isolation (negative), food frustration (negative), as well as 1 playback involving dog barks (negative) were presented on the left and right sides of the test subjects simultaneously. The head-orienting response (left or right) and latency to resume feeding were recorded. The direction of the head-orienting response did not differ between the various playbacks. However, when the head-orienting response was tested against chance level, goats showed a right bias regardless of the stimuli presented. Goats responded more to dog barks than to food frustration calls, whereas responses to food anticipation and isolation calls were intermediate. In addition, the latency to resume feeding, an indicator of fear reaction, was not affected by the kind of vocalization presented. These results provide evidence for asymmetries in goat vocal perception of emotional-linked conspecific and heterospecific calls. They also suggest involvement of the left brain hemisphere for processing acoustic stimuli, which might have been perceived as familiar and non-threatening

Insect sentience and the rise of a new inclusive ethics

Welfare protections for vertebrates are grounded in the belief that vertebrates are sentient and capable of feeling whereas invertebrates are not. We agree with Mikhalevich & Powell that the exclusion of small-brained invertebrates from bioethics is not warranted by the current state of the scientific evidence. The choice to promote protection for certain invertebrates should be based on the Animal Sentience Precautionary Principle (ASPP). This principle should not prevent us from conducting experimental research with non-human animals to advance knowledge. However, we believe that it is important to outline practical guidelines to manage the wellbeing of invertebrates, while accumulating further evidence on their inner life