Animal Welfare Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, Canada.
Department of Immunology, Pathophysiology and Veterinary Preventive Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
Anim Cogn. 2024 Oct 12;27(1):66. doi: 10.1007/s10071-024-01905-2.
Spatial judgement bias tests (JBTs) can involve teaching animals that a bowl provides a reward in one location but does not in another. The animal is then presented with the bowl placed between the rewarded and the unrewarded locations (i.e., ambiguous locations) and their latency to approach reflects expectation of reward or 'optimism'. Some suggest that greater 'optimism' indicates better welfare. Performance in JBTs, however, may also indicate a learning history independently from welfare determinants. We hypothesized that dogs' 'optimism' in a follow-up JBT may be impacted by a learning treatment involving additional trials of a different discrimination task. Once enrolled, companion dogs (n = 16) were required to complete three study phases: (1) a pre-treatment JBT, (2) a learning treatment, and (3) a post-treatment JBT. During the JBTs, dogs were presented with five locations: one rewarded, one unrewarded, and three ambiguous (all unrewarded). Dogs were randomly assigned to a trial-based learning task-a nose-touch to the palm of the hand. In the Experimental discrimination treatment phase (n = 8), dogs were presented with two hands in each trial and only rewarded for touching one specific hand. In the Control treatment phase (n = 8), dogs were presented with one hand per trial in alternating sequence and were yoked to dogs in the Experimental group to receive the same number of rewarded and unrewarded trials (to control for possible frustration). Using a repeated measures mixed model with JBT repeated within dog, we found no difference in the change in approach latency to the ambiguous locations between the dogs across treatments. 'Optimism' as measured in this JBT was not altered by the additional discrimination trials used in our study.
空间判断偏差测试（JBT）可以包括教动物一个碗在一个位置提供奖励，但在另一个位置不提供奖励。然后，将碗放在奖励和非奖励位置（即，不确定位置）之间呈现给动物，它们接近的潜伏期反映了对奖励的期望或“乐观”。有人认为，更大的“乐观”表明更好的福利。然而，JBT 中的表现也可能独立于福利决定因素反映学习历史。我们假设，在后续 JBT 中，狗的“乐观”可能会受到涉及不同辨别任务的额外试验的学习处理的影响。一旦入组，伴侣犬（n=16）必须完成三个研究阶段：（1）预处理 JBT，（2）学习处理，和（3）后处理 JBT。在 JBT 期间，狗被呈现五个位置：一个奖励，一个不奖励，三个不确定（全部不奖励）。狗被随机分配到基于试验的学习任务——用鼻子触碰手掌。在实验辨别处理阶段（n=8），每轮试验呈现两只手，只有触摸一只特定的手才能获得奖励。在对照处理阶段（n=8），每轮试验呈现一只手，交替呈现，与实验组的狗相匹配，以获得相同数量的奖励和非奖励试验（以控制可能的挫折感）。使用基于 JBT 重复的重复测量混合模型，我们发现处理之间狗在不确定位置接近潜伏期变化方面没有差异。在我们的研究中使用的额外辨别试验没有改变 JBT 中测量的“乐观”。
