Abstract: Observation of behaviour, especially social behaviour, and experimental studies of learning and brain function give us information about the complexity of concepts that animals have. In order to learn to obtain a resource or carry out an action, domestic animals may: relate stimuli such as human words to the reward, perform sequences of actions including navigation or detours, discriminate amongst other individuals, copy the actions of other individuals, distinguish between individuals who do or do not have information, or communicate so as to cause humans or other animals to carry out actions. Some parrots, that are accustomed to humans but not domesticated, can use words to have specific meanings. In some cases, stimuli, individuals or actions are remembered for days, weeks or years. Events likely to occur in the future may be predicted and changes over time taken into account. Scientific evidence for the needs of animals depends, in part, on studies assessing motivational strength whose methodology depends on the cognitive ability of the animals. Recognition and learning may be associated with changes in physiology, behaviour and positive or negative feelings. Learning and other complex behaviour can result in affect and affect can alter cognition. The demonstration of cognitive bias gives indications about affect and welfare but should be interpreted in the light of other information. All of the information mentioned so far helps to provide evidence about sentience and the level of awareness. The term sentience implies a range of abilities, not just the capacity to have some feelings. The reluctance of scientists to attribute complex abilities and feelings to non-humans has slowed the development of this area of science. Most people consider that they have obligations to some animals. However, they might protect animals because they consider that an animal has an intrinsic value, or because of their concern for its welfare. In social species, there has been selection promoting moral systems that might result in behaviours such as attempts to avoid harm to others, collaboration and other altruistic behaviour. An evaluation of such behaviour may provide one of the criteria for decisions about whether or not to protect animals of a particular species. Other criteria may be: whether or not the animal is known as an individual, similarity to humans, level of awareness, extent of feelings, being large, being rare, being useful or having aesthetic quality for humans. Cognitive ability should also be considered when designing methods of enriching the environments of captive animals.

Abstract: Lateralization of emotions has received great attention in the last decades, both in humans and animals, but little interest has been given to side bias in perceptual processing. Here, we investigated the influence of the emotional valence of stimuli on visual and olfactory explorations by horses, a large mammalian species with two large monocular visual fields and almost complete decussation of optic fibres. We confronted 38 Arab mares to three objects with either a positive, negative or neutral emotional valence (novel object). The results revealed a gradient of exploration of the 3 objects according to their emotional value and a clear asymmetry in visual exploration. When exploring the novel object, mares used preferentially their right eyes, while they showed a slight tendency to use their left eyes for the negative object. No asymmetry was evidenced for the object with the positive valence. A trend for an asymmetry in olfactory investigation was also observed. Our data confirm the role of the left hemisphere in assessing novelty in horses like in many vertebrate species and the possible role of the right hemisphere in processing negative emotional responses. Our findings also suggest the importance of both hemispheres in the processing positive emotions. This study is, to our knowledge, the first to demonstrate clearly that the emotional valence of a stimulus induces a specific visual lateralization pattern.

Abstract: Handling is a crucial component of the human-horse relationship. Here, we report data from an experiment conducted to assess and compare the effect of two training methods. Two groups of six Welsh mares were trained during four sessions of 50 min, one handled with traditional exercises (halter leading, grooming/brushing, lifting feet, lunging and pseudo-saddling (using only girth and saddle pad) and the second group with natural horsemanship exercises (desensitization, yielding to body pressure, lunging and free-lunging). Emotional reactivity (ER) and the human-horse relationship (HHR) were assessed both prior to and following handling. A social isolation test, a neophobia test and a bridge test were used to assess ER. HHR was assessed through test of spontaneous approach to, and forced approach by, an unknown human. Horses' ER decreased after both types of handling as indicated by decreases in the occurrence of whinnying during stressful situations. Head movement (jerk/shake) was the most sensitive variable to handling type. In the spontaneous approach tests, horses in the traditional handling group showed higher latencies to approach a motionless person after handling than did the natural horsemanship group. Our study suggests that natural horsemanship exercises could be more efficient than traditional exercises for improving horses' HHR.

Abstract: In the present study, we sought to determine the influence of stress and temperament on working memory for disappearing food in horses. After assessment of five dimensions of temperament, we tested working memory of horses using a delayed-response task requiring a choice between two food locations. Delays ranging from 0 to 20 s were tested. The duration of working memory for disappearing food was first characterized without stressors (N = 26). The horses were then divided into two groups and their performance was assessed under stressful (exposure to acute stressors prior to testing, N = 12) or control conditions (N = 12). Results showed that the duration of working memory for disappearing food lasted at least 20 s under nonstressful conditions, and that under stressful conditions this duration lasted less than 12 s. This stress-induced impairment confirms in a nonrodent species that working memory performance is very sensitive to exposure to stressors. In addition, working memory performance in horses is influenced by the temperamental dimension of fearfulness according to the state of stress: fearful horses showed better performance under control conditions and worse performance under stressful conditions than nonfearful horses. These findings are discussed in the context of the Yerkes–Dodson law of stress and performance.