title: Toward a Choice-Based Judgment Bias Task for Horses.
abstract: Judgment bias tasks for nonhuman animals are promising tools to assess emotional valence as a measure of animal welfare. In view of establishing a valid judgment bias task for horses, the present study aimed to evaluate 2 versions (go/no-go and active choice) of an auditory judgment bias task for horses in terms of acquisition learning and discrimination of ambiguous cues. Five mares and 5 stallions were randomly assigned to the 2 designs and trained for 10 trials per day to acquire different operant responses to a low-frequency tone and a high-frequency tone, respectively. Following acquisition learning, horses were tested on 4 days with 3 ambiguous-tone trials interspersed between the 10 high-tone and low-tone trials. All 5 go/no-go horses but only one active-choice horse successfully learned their task, indicating that it is more difficult to train horses on an active choice task than on a go/no-go task. During testing, however, go/no-go horses did not differentiate between the 3 different ambiguous cues, thereby making the validity of the test results questionable in terms of emotional valence.
authors.affiliation: a Division of Animal Welfare, VPH Institute , University of Bern , Bern , Switzerland.|b Agroscope, Swiss National Stud Farm , Avenches , Switzerland.
authors.forename: Sara
authors.initials: S
authors.lastname: Hintze
authors.affiliation: c Department of Clinical Biochemistry , Cambridge Institute of Metabolic Science, University of Cambridge , Cambridge , United Kingdom.
authors.forename: Emma
authors.initials: E
authors.lastname: Roth
authors.affiliation: b Agroscope, Swiss National Stud Farm , Avenches , Switzerland.
authors.forename: Iris
authors.initials: I
authors.lastname: Bachmann
authors.affiliation: a Division of Animal Welfare, VPH Institute , University of Bern , Bern , Switzerland.
authors.forename: Hanno
authors.initials: H
authors.lastname: Würbel
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods / Q000662:veterinary; D000827:Animal Welfare; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002755:Choice Behavior; D003071:Cognition / Q000502:physiology*; D003216:Conditioning, Operant / Q000502:physiology*; D003463:Cues; D004644:Emotions; D005260:Female; D006736:Horses / Q000523:psychology*; D007600:Judgment; D007858:Learning / Q000502:physiology; D008297:Male; D011897:Random Allocation; D012201:Reward; D013557:Switzerland
keywords: Animal welfare; cognitive bias; emotional state; horse; mood