Mood induction alters attention toward negative-positive stimulus pairs in sheep

Abstract

Mood is a lasting affective state that influences motivation and decision-making by pre-shaping a subject’s expectations (pessimism/optimism). Mood states affect biases in judgment, memory, and attention. Due to a lack of verbal report, assessing mood in non-human animals is challenging and is often compromised by intense training sessions. Measuring mood using attentional biases can circumvent this problem, as it takes advantage of observing a spontaneous reaction. As in humans, we expected that negative mood will heighten attention toward negative compared to positive stimuli. Here, we validate measures of attention toward acoustic stimuli in sheep (N = 64) and assess sheep’s differential attention toward acoustic stimuli before and after mood induction (N = 32). Mood was induced by manipulating the environment. We used animal vocalizations (dog barking and sheep bleating as negative and positive stimuli, respectively) varying in intensity and played simultaneously from one side each, and measured lateral attention based on the sheep’s behavior. Overall results were somewhat ambiguous. Yet, negative mood sheep seemed to shift their attention more toward dog vocalizations when the stimulus pair was well balanced at baseline. Though some adaptations are still needed, our approach could be a promising alternative to measure animals’ mood without prior training.

Attention Bias Test Measures Negative But Not Positive Affect in Sheep: A Replication Study

“…Within the current test paradigm, sniffing behaviors may indicate olfactory attention, and have been shown to differ significantly between Anxious sheep and other treatment groups in the current and previous studies [24,26]. Auditory attention can be characterized during testing by assessing ear postures [57,58], however, assessment of ear postures is labor-intensive and time-consuming and will limit the practical application of the method. Further, we suggest that the assessment of auditory and olfactory attention will be more meaningful in test paradigms that incorporate auditory and olfactory cues associated with the positive and negative stimuli.…”

“…Further, we suggest that the assessment of auditory and olfactory attention will be more meaningful in test paradigms that incorporate auditory and olfactory cues associated with the positive and negative stimuli. Indeed, the potential to use auditory stimuli to assess attention bias in sheep has already been explored with promising results, using behavior to assess lateral attention towards audio stimuli that were simultaneously played on either side of the animal [58]. It should also be considered that the stimuli presented in this study were cross-modal.…”

Goats show higher behavioural flexibility than sheep in a spatial detour task

“…They had straw bedding available, hay was provided twice a day at a regular time and water was available ad libitum. All the animals were habituated to being handled by an experimenter (CMCR) and took part in previous experiments involving acoustic stimuli [ 42 ].…”

Towards a Positive Welfare Protocol for Cattle: A Critical Review of Indicators and Suggestion of How We Might Proceed

“…In humans, most research has been on negative attention bias with only a few studies investigating positive attention bias (e.g., Tamir and Robinson, 2007;Grafton et al, 2012). The same holds true for non-human animals, with most studies investigating negative attention bias in sheep (e.g., Lee et al, 2016;Monk et al, 2018;Raoult and Gygax, 2019). Two studies aiming to pharmacologically validate positive and negative attention bias in sheep failed to do so (Monk et al, 2019(Monk et al, , 2020, which suggests that positive attention bias may be difficult to assess in nonhuman animals.…”