affective states; mood; emotion; cortical brain activity; haemodynamic changes; functional near-infrared spectroscopy; sheep; human subjects
Gygax Lorenz, Vögeli Sabine (2016), Reactions of sheep towards three sets of emotional stimuli: (In)Consistency in respect to stimulus valence and sheep identity, in Applied Animal Behaviour Science
, 174(1), 51-57.
Vögeli Sabine, Wolf Martin, Wechsler Beat, Gygax Lorenz (2015), Frontal brain activity and behavioral indicators of affective states are weakly affected by thermal stimuli in sheep living in different housing conditions, in Frontiers in Veterinary Science
, 2, 1-10.
Guldimann Kathrin, Vögeli Sabine, Wolf Martin, Wechsler Beat, Gygax Lorenz (2015), Frontal brain deactivation during a non-verbal cognitive judgement bias test in sheep, in Brain & Cognition
, 93, 35-41.
Vögeli Sabine, Wolf Martin, Wechsler Beat, Gygax Lorenz (2015), Housing conditions influence cortical and behavioural reactions of sheep in response to videos showing social interactions of different valence, in Behavioural Brain Research
, 284(1), 69-76.
Gygax Lorenz (2014), The A to Z of statistics for testing cognitive judgement bias, in Animal Behaviour
, 95, 59-69.
Voegeli Sabine, Lutz Janika, Wolf Martin, Wechsler Beat, Gygax Lorenz (2014), Valence of physical stimuli, not housing conditions, affects behaviour and frontal cortical brain activity in sheep, in Behavioural Brain Research
, 267, 144-155.
Vögeli Sabine, Wechsler Beat, Gygax Lorenz (2014), Welfare by the ear: comparing relative durations and frequencies of ear postures by using an automated tracking system in sheep, in Animal Welfare
, 23(8), 267-274.
Long-term affective states, i.e. mood, and short-term affective reactions, i.e. emotions, are important mechanisms of behavioural control in humans and other mammals. In addition to basic scientific questions that also appeal to the general public on how mood and stimulus valence control emotions, affective states are also of both scientific and public interest with regard to the welfare of intensively kept farm and laboratory animals. It is largely unclear how mood interacts with stimulus valence in producing emotional reactions. We thus plan to extend previous approaches on the influence of clinical mood aberrations such as depression on positive emotional experiences by focusing on non-clinical variation of mood, both negative and positive, and by including the complete range of valence of stimuli (negative to positive).Because affective states are subjective, indicator variables are used to assess such states. In humans, the recent availability of imaging techniques has boosted the research on in-vivo brain reactions in response to stimuli of varying valence but similar studies on freely-moving subjects and on animals are lacking. In our study, we want to apply non-invasive functional near-infrared spectroscopy (fNIRS) to measure cortical haemodynamic reactions (similar to fMRI and PET measurements) in freely-moving sheep and human subjects as model species. The choice of species is based on the fact, that we have successfully applied this method in a preliminary experiment on sheep and that we can relate fNIRS measurement to subjectively perceived emotions in humans. In both species, the fNIRS measurement will be complemented by measuring behavioural and physiological indicator variables.Our previous experiment has shown that sheep in a negative mood react more strongly to the presumably positive stimulus of being groomed compared to sheep in a positive mood. To show the generality of this response, we plan to extend the range of stimuli and the range of types of valence to fully appreciate how mood interacts with stimulus valence in producing cortical brain reactions. After inducing different moods in two groups of sheep by varying their housing conditions, we want to investigate cortical haemodynamic reactions in response to stimuli likely to induce affective reactions. In a series of experiments, we will vary the valence of touch (negative: piercing, neutral: pressure, positive: brushing), temperature (negative: hot, neutral: body temperature, positive: cool) and social stimuli (negative: agonistic behaviour, neutral: non-social behaviour, positive: affiliative behaviour). The two experiments using temperature and social stimuli will be replicated with human subjects evaluating their naturally occurring variance in mood.Based on our results, we will be able to characterise typical emotional cortical reactions in two mammal species (sheep and human subjects) to stimuli differing in valence and to different stimuli of the same valence. Moreover, we will be able to assess how mood interacts with stimulus valence in producing cortical activity. The latter will provide new evidence on how mood controls behaviour and has direct consequences for the applied question of animal welfare. Our results will show whether the negative impact of short-term manipulations can be outweighed by a housing system that induces a positive mood and whether a generally negative mood taints positive experiences in the everyday life of sheep.