Positive emotions, attention and welfare in horses

L’évaluation des émotions positives chez l’animal est encore délicate. Pourtant, de nombreuses évidences démontrent l’intérêt de favoriser l’expression de ces émotions, notamment dans le but d’améliorer le bien-être des individus. Cette recherche vise à valider et identifier des indicateurs d’émotions positives chez le cheval. Dans un premier temps, une étude expérimentale basée sur l’utilisation d’accéléromètres, tout comme l’observation d’épisodes d’anticipation alimentaire quotidiens en centre équestre, ont permis d’identifier le déclenchement de l’anticipation et de mieux caractériser les comportements exprimés dans ce cadre. Nos résultats dévoilent que les comportements d’anticipation reflètent davantage un état de frustration. Ils ne constituent donc pas un indicateur fiable d’émotions positives. En revanche, une augmentation d’intensité de ces comportements semble indiquer un état de mal-être. Puis, en nous appuyant sur l’utilisation d’un casque permettant la mesure de l’activité électroencéphalographique chez des chevaux éveillés et libres de leurs mouvements, nous avons pu (i) confirmer l’importance de l’hémisphère gauche dans le traitement des émotions positives et de l’hémisphère droit dans le traitement attentionnel, (ii) mettre en évidence le rôle majeur des ondes thêta lors d’un traitement cognitif attentionnel, (iii) souligner l’interaction des processus émotionnels et attentionnels chez le cheval. Par ailleurs, si le test classique d’attention visuelle (VAT) constitue un bon outil de mesure des capacités attentionnelles d’un cheval au travail, ce même test réalisé sans humain apparait être un outil novateur de mesure de l’état de bien-être. Enfin, l’étude de la production de sons non-vocaux, basée sur une approche comparative combinant l’observation de chevaux de centre équestre et des chevaux vivant en condition semi-naturelle (favorable au bien-être), a révélé que l’ébrouement (hors contrainte respiratoire liée à une maladie ou à un équipement mal ajusté) serait un marqueur fiable d’émotions positives d’intensité modérée chez le cheval, puisqu’il exprimerait que ce dernier perçoit de façon positive son environnement. L’ensemble des recherches menées dans ce travail ouvrent vers des perspectives d’applications intéressantes dans le milieu équin, mais aussi d’un point de vue fondamental et méthodologique.Indicators of positive emotions in animals are still scarce. However, many studies showed that favour these emotions is a promising way to improve individual welfare state. This study aims to validate and identify some indicators of positive emotions in horses. First, based both on an experimental study using accelerometers and the observation of riding school horses during their regular feeding time, we characterized anticipatory behaviours in this specie and showed that they were triggered by an environmental cue. Moreover, anticipatory behaviours were associated with frustration and thus were not reliable indicators of positive emotions. However, an increase of their intensity may reflect a poor welfare state. Then, the use of an EEG helmet designed for awake horses free from their movements, allowed us to (i) confirm the left-hemisphere bias for positive emotions processes and the right hemisphere bias for attentional processes, (ii) highlight the implication of theta waves in cognitive attentional processes, (iii) underline interactions between attentional and emotional processes in horses. Moreover, we showed that the measures of attentional characteristics thanks to a visual attention test (VAT) was useful to define attentional capacities at work. The same test conducted without a human was rather useful to evaluate the horses’ welfare state. Finally, a comparative approach based on the observation of horses living either in restricted or in naturalistic conditions revealed that snort (out of breathing difficulties due to illness or poorly fitting equipment) could be a reliable indicator of positive emotions of low intensity as it would be the expression of the horses’ positive appraisal of a situation. This works opens up promising fundamental and applied perspectives and applications

Attention et positivisme au cœur du bien-être chez le cheval

Indicators of positive emotions in animals are still scarce. However, many studies showed that favour these emotions is a promising way to improve individual welfare state. This study aims to validate and identify some indicators of positive emotions in horses. First, based both on an experimental study using accelerometers and the observation of riding school horses during their regular feeding time, we characterized anticipatory behaviours in this specie and showed that they were triggered by an environmental cue. Moreover, anticipatory behaviours were associated with frustration and thus were not reliable indicators of positive emotions. However, an increase of their intensity may reflect a poor welfare state. Then, the use of an EEG helmet designed for awake horses free from their movements, allowed us to (i) confirm the left-hemisphere bias for positive emotions processes and the right hemisphere bias for attentional processes, (ii) highlight the implication of theta waves in cognitive attentional processes, (iii) underline interactions between attentional and emotional processes in horses. Moreover, we showed that the measures of attentional characteristics thanks to a visual attention test (VAT) was useful to define attentional capacities at work. The same test conducted without a human was rather useful to evaluate the horses’ welfare state. Finally, a comparative approach based on the observation of horses living either in restricted or in naturalistic conditions revealed that snort (out of breathing difficulties due to illness or poorly fitting equipment) could be a reliable indicator of positive emotions of low intensity as it would be the expression of the horses’ positive appraisal of a situation. This works opens up promising fundamental and applied perspectives and applications.L’évaluation des émotions positives chez l’animal est encore délicate. Pourtant, de nombreuses évidences démontrent l’intérêt de favoriser l’expression de ces émotions, notamment dans le but d’améliorer le bien-être des individus. Cette recherche vise à valider et identifier des indicateurs d’émotions positives chez le cheval. Dans un premier temps, une étude expérimentale basée sur l’utilisation d’accéléromètres, tout comme l’observation d’épisodes d’anticipation alimentaire quotidiens en centre équestre, ont permis d’identifier le déclenchement de l’anticipation et de mieux caractériser les comportements exprimés dans ce cadre. Nos résultats dévoilent que les comportements d’anticipation reflètent davantage un état de frustration. Ils ne constituent donc pas un indicateur fiable d’émotions positives. En revanche, une augmentation d’intensité de ces comportements semble indiquer un état de mal-être. Puis, en nous appuyant sur l’utilisation d’un casque permettant la mesure de l’activité électroencéphalographique chez des chevaux éveillés et libres de leurs mouvements, nous avons pu (i) confirmer l’importance de l’hémisphère gauche dans le traitement des émotions positives et de l’hémisphère droit dans le traitement attentionnel, (ii) mettre en évidence le rôle majeur des ondes thêta lors d’un traitement cognitif attentionnel, (iii) souligner l’interaction des processus émotionnels et attentionnels chez le cheval. Par ailleurs, si le test classique d’attention visuelle (VAT) constitue un bon outil de mesure des capacités attentionnelles d’un cheval au travail, ce même test réalisé sans humain apparait être un outil novateur de mesure de l’état de bien-être. Enfin, l’étude de la production de sons non-vocaux, basée sur une approche comparative combinant l’observation de chevaux de centre équestre et des chevaux vivant en condition semi-naturelle (favorable au bien-être), a révélé que l’ébrouement (hors contrainte respiratoire liée à une maladie ou à un équipement mal ajusté) serait un marqueur fiable d’émotions positives d’intensité modérée chez le cheval, puisqu’il exprimerait que ce dernier perçoit de façon positive son environnement. L’ensemble des recherches menées dans ce travail ouvrent vers des perspectives d’applications intéressantes dans le milieu équin, mais aussi d’un point de vue fondamental et méthodologique

Are positive emotions reliable indicators of welfare in horses?

International audienceAssessing horse welfare is a crucial issue for obvious ethical reasons but also because it has been shown to have an impact on reproductive and cognitive abilities. Welfare also affects the relationship of horses with humans both at work and outside work; it enhances security for people and thus it constitutes a social issue too. Studies combining behavioural, postural, physiological and sanitary data suggest that it is possible to identify and validate indicators of altered welfare but also of well-being, that is, of a positive affective state. Although it has been proposed that positive affective states could arise from the sum of positive emotions experienced daily, the link between these short term experiences and the chronic state that characterizes the welfare state is not clear yet. Indeed, emotions are short-lived affective reactions but do not necessary depict the chronic state of the animal. Moreover, identifying expressions of positive emotions remains more difficult than identifying those of negative emotions. Also discriminate valence (positive/negative) from intensity (high/low) when measuring emotions is both necessary and delicate. For example, adult play or anticipatory behaviours may not have the same valence if one considers the short term or the chronic affective state but are both of high intensity. On the other hand, other low intensity indicators of positive emotions emerge that might be better candidates for revealing a “well-being” state. The aim of this review is to propose a critical view of measuring short experienced positive emotions, evaluating their interest for welfare assessment and present novel perspectives of investigation through behavioural and electrophysiological recordings

Are positive emotions reliable indicators of welfare in horses?

International audienceAssessing horse welfare is a crucial issue for obvious ethical reasons but also because it has been shown to have an impact on reproductive and cognitive abilities. Welfare also affects the relationship of horses with humans both at work and outside work; it enhances security for people and thus it constitutes a social issue too. Studies combining behavioural, postural, physiological and sanitary data suggest that it is possible to identify and validate indicators of altered welfare but also of well-being, that is, of a positive affective state. Although it has been proposed that positive affective states could arise from the sum of positive emotions experienced daily, the link between these short term experiences and the chronic state that characterizes the welfare state is not clear yet. Indeed, emotions are short-lived affective reactions but do not necessary depict the chronic state of the animal. Moreover, identifying expressions of positive emotions remains more difficult than identifying those of negative emotions. Also discriminate valence (positive/negative) from intensity (high/low) when measuring emotions is both necessary and delicate. For example, adult play or anticipatory behaviours may not have the same valence if one considers the short term or the chronic affective state but are both of high intensity. On the other hand, other low intensity indicators of positive emotions emerge that might be better candidates for revealing a “well-being” state. The aim of this review is to propose a critical view of measuring short experienced positive emotions, evaluating their interest for welfare assessment and present novel perspectives of investigation through behavioural and electrophysiological recordings

Horses’ attentional characteristics differ according to the type of work

International audienceAttention is a central process of cognition and influences the execution of daily tasks. In humans, different types of work require different attentional skills and sport performance is associated with the ability to attention shift. Attention towards humans varies in dogs used for different types of work. Whether this variation is due to the recruitment of individuals suitable for specific types of work, or to the characteristics of the work, remains unclear. In the present study, we hypothesized that domestic horses (Equus caballus) trained for different types of work would also demonstrate different attentional characteristics but we also explored other possible factors of influence such as age, sex and breed. We exposed more than sixty horses, working in 4 different disciplines, and living in two types of housing conditions, to a visual attention test (VAT) performed in the home environment. Individual attentional characteristics in the test were not significantly influenced by age, sex, breed or conditions of life but were strongly related to the type of work. Riding school horses showed longer sequences and less fragmented attention than all other horses, including sport horses living in the same conditions. Interestingly, sport performance was correlated with attention fragmentation during the test in eventing horses, which may need more attention shifting during the competitions. Working conditions may influence attention characteristics indirectly through welfare, or directly through selection and training. Our study opens new lines of thought on the determinants of animal cognition and its plasticity and constitutes a further step towards understanding the interrelationship between working conditions and cognition

Horses’ attentional characteristics differ according to the type of work

Attention is a central process of cognition and influences the execution of daily tasks. In humans, different types of work require different attentional skills and sport performance is associated with the ability to attention shift. Attention towards humans varies in dogs used for different types of work. Whether this variation is due to the recruitment of individuals suitable for specific types of work, or to the characteristics of the work, remains unclear. In the present study, we hypothesized that domestic horses (Equus caballus) trained for different types of work would also demonstrate different attentional characteristics but we also explored other possible factors of influence such as age, sex and breed. We exposed more than sixty horses, working in 4 different disciplines, and living in two types of housing conditions, to a visual attention test (VAT) performed in the home environment. Individual attentional characteristics in the test were not significantly influenced by age, sex, breed or conditions of life but were strongly related to the type of work. Riding school horses showed longer sequences and less fragmented attention than all other horses, including sport horses living in the same conditions. Interestingly, sport performance was correlated with attention fragmentation during the test in eventing horses, which may need more attention shifting during the competitions. Working conditions may influence attention characteristics indirectly through welfare, or directly through selection and training. Our study opens new lines of thought on the determinants of animal cognition and its plasticity and constitutes a further step towards understanding the interrelationship between working conditions and cognition

La prise de décision sous risque de gain chez les mangabeys à collier (Cercocebus torquatus torquatus)

International audienceLa prise de décision sous risque de gain chez les primates est actuellement sujette à débat au sein de la communauté scientifique. Contrairement aux humains adultes, une appétence au risque dans le domaine du gain est généralement observée chez les macaques rhésus et les grands singes. Nous avons étudié le comportement de 17 mangabeys à collier (Cercocebus torquatus torquatus) dans une situation de pari impliquant une récompense alimentaire. Dans cette tâche les sujets devaient choisir entre deux options : l’une sûre et l’autre risquée. Dans la nature, les mangabeys ont une alimentation frugivore qui exploite des ressources incertaines. Supposant chez eux une plus grande tolérance au risque en ce qui concerne la nourriture, notre hypothèse était que les mangabeys montreraient une tendance à la prise de risque dans notre tâche expérimentale. Dans l’expérience 1, les individus ont montré une préférence pour l’option risquée par rapport à l’option sûre. Afin de tester l’hypothèse selon laquelle les choix risqués des mangabeys reflètent des difficultés dans le contrôle inhibiteur, les sujets ont été exposés dans l’expérience 2 à un dispositif expérimental similaire excepté que le cache opaque sous lequel était placée l’option sûre a été remplacé par un cache transparent. Dans cette seconde expérience, les mangabeys ont montré une préférence pour l’option sûre par rapport à l’option risquée à l’essai 1, mais ont changé leur préférence économique à l’essai 2. Ces résultats permettent d’écarter l’hypothèse selon laquelle les choix risqués des mangabeys reflètent uniquement un faible contrôle comportemental. Nous suggérons que (i) les mangabeys présentent une appétence au risque dans le domaine du gain, et (ii) les préférences économiques chez cette espèce résultent de stratégies de prises de décision liées à leur histoire évolutive

La prise de décision sous risque de gain chez les mangabeys à collier (Cercocebus torquatus torquatus)

International audienceLa prise de décision sous risque de gain chez les primates est actuellement sujette à débat au sein de la communauté scientifique. Contrairement aux humains adultes, une appétence au risque dans le domaine du gain est généralement observée chez les macaques rhésus et les grands singes. Nous avons étudié le comportement de 17 mangabeys à collier (Cercocebus torquatus torquatus) dans une situation de pari impliquant une récompense alimentaire. Dans cette tâche les sujets devaient choisir entre deux options : l’une sûre et l’autre risquée. Dans la nature, les mangabeys ont une alimentation frugivore qui exploite des ressources incertaines. Supposant chez eux une plus grande tolérance au risque en ce qui concerne la nourriture, notre hypothèse était que les mangabeys montreraient une tendance à la prise de risque dans notre tâche expérimentale. Dans l’expérience 1, les individus ont montré une préférence pour l’option risquée par rapport à l’option sûre. Afin de tester l’hypothèse selon laquelle les choix risqués des mangabeys reflètent des difficultés dans le contrôle inhibiteur, les sujets ont été exposés dans l’expérience 2 à un dispositif expérimental similaire excepté que le cache opaque sous lequel était placée l’option sûre a été remplacé par un cache transparent. Dans cette seconde expérience, les mangabeys ont montré une préférence pour l’option sûre par rapport à l’option risquée à l’essai 1, mais ont changé leur préférence économique à l’essai 2. Ces résultats permettent d’écarter l’hypothèse selon laquelle les choix risqués des mangabeys reflètent uniquement un faible contrôle comportemental. Nous suggérons que (i) les mangabeys présentent une appétence au risque dans le domaine du gain, et (ii) les préférences économiques chez cette espèce résultent de stratégies de prises de décision liées à leur histoire évolutive

EEG profile might be a new objective physiological marker of horses' welfare

International audienceAssessing welfare of horses, which is a particularly critical point in terms of ethics, safety and performance, is still under debated. Although, clear behavioral and postural indicators have been validated, their use remains restricted to persons trained to observational techniques and the physiological parameters used so far gave contradictory results. Furthermore, these indicators concern particularly horses' ill-being. Therefore, in order to assess clearly and simply horses' welfare we need objective markers that can be used by non-specialists.Recently, it has been shown that a horse in a good welfare level seems to be quiet and attentive to its environment. The telemetric EEG headset developed in our lab allowed us to show that horse attentional state can alter the EEG profile (proportion of brain waves). In the light of these results we hypothesize that welfare may also alter EEG profile and that EEG profile may become a good objective physiological marker of welfare. In order to test this hypothesis, we performed EEG recordings on two populations of horses living in two different environment and presenting different welfare levels. One population was living in riding center with restricted conditions (single stalls, limited access to roughage…) and the other population was living in naturalistic conditions (stable groups, pasture with grass or hay adlibitum…). The welfare of these horses was precisely evaluated using behavioral markers. We recorded separately the EEG of the left and right hemispheres of the horses while they were quietly watching their environment. We then built the individual EEG profiles (proportion of the different brainwaves) of left and right hemisphere.The results show a clear difference of well-being of both populations, horses living in naturalistic conditions presented a well-being state clearly better than the horses living in riding center. The EEG profiles varied as a function of the population and were correlated to horse well-being. These results show that EEG may become a new objective marker of welfare in horses

Brain activity reflects (chronic) welfare state: evidence from individual electroencephalography profiles in an animal model

International audienceAssessing the animal welfare state is a challenge given the subjective individual cognitive and emotional processing involved. Electroencephalography (EEG) spectrum analysis has proved an ecologically valid recording situation to assess the link between brain processes and affective or cognitive states in humans: a higher slow wave/fast wave ratio has been associated with a positive internal state. In particular, a high production of theta power (3-8 Hz) has been related to positive emotions. On the other hand, it has been hypothesized that a left hemisphere (LH) dominance may be associated with a better welfare state. Here, we test the hypothesis that individual differences in the resting-state quantitative EEG power spectrum of adult horses (N = 18) and its lateralization pattern may reflect individual subjective perception of their conditions of life and welfare state. The results show clear individual differences in the proportions of the different waves and their inter-hemispheric distribution. Three different EEG power spectrum profiles were highlighted, from a bilateral predominance of theta waves in horses in a more positive welfare state to a bilateral predominance of beta waves in horses with clear expressions of compromised welfare. Interestingly, particular correlations were found between wave power activity and welfare parameters. We found a negative correlation between the number of stereotypic behaviours per hour and the median proportion of theta waves in the left hemisphere. and between the overall state (total chronic stress score) of welfare and gamma production in the right hemisphere (RH). These findings go along the hypothesis of a particular involvement of the left hemisphere for positive processing and of the right hemisphere for negative processing. However, the pattern of laterality did not appear as the most important feature here as both extreme clusters in terms of welfare showed bilateral predominance of one wave type. It is possible that hemispheric specialization makes more sense during acute emotion-inducing conditions rather than in this resting-state context (i.e. in absence of any high emotion-inducing stimulation), although the opposition gamma versus theta waves between both hemispheres in the horses with an intermediate welfare state is noticeable and intriguing. It seems that bilateral but also LH theta activity is a promising neurophysiological marker of good welfare in horses, while a bilateral or RH high production of gamma waves should alert about potential welfare alterations.Quantitative resting-state EEG power spectrum appears as a highly promising tool for exploring the brain processes involved in the subjective perception of chronic welfare, as a useful complementary tool for welfare assessment