Dipartimento di Medicina e Chirurgia, Università degli Studi di Parma, Parma, Italia.
Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università degli Studi di Parma, Parma, Italia.
PLoS One. 2020 Oct 27;15(10):e0241344. doi: 10.1371/journal.pone.0241344. eCollection 2020.
It is now widely agreed that a positive affective state is a crucial component of animal well-being. The judgment bias test represents a widespread tool used to assess animals' optimistic/pessimistic attitude and to evaluate their emotional state and welfare. Judgment bias tests have been used several times with dogs (Canis familiaris), in most cases using a spatial test with a bowl placed in ambiguous positions located between a relatively positive trained location (P) which contains a baited bowl and a relatively negative trained location (N) which contains an empty bowl. The latency to approach the bowl in the ambiguous locations is an indicator of the dog's expectation of a positive/negative outcome. However, results from such tests are often inconclusive. For the present study, the judgment bias test performance of 51 shelter dogs and 40 pet dogs was thoroughly analysed. A pattern emerged with shelter dogs behaving in a more pessimistic-like way than pet dogs. However, this difference between the two populations was detected only when analysing the raw latencies to reach the locations and not the more commonly applied adjusted score (i.e. average latency values). Furthermore, several methodological caveats were found. First of all, a non-negligible percentage of dogs did not pass the training phase, possibly due to the experimental paradigm not being fully suited for this species. Second, results showed a high intra-dog variability in response to the trained locations, i.e. the dogs' responses were not consistent throughout the test, suggesting that animals may not have fully learned the association between locations and their outcomes. Third, dogs did not always behave differently towards adjacent locations, raising doubts about the animals' ability to discriminate between locations. Finally, a potential influence of the researcher's presence on dogs' performance emerged from analyses. The implications of these findings and potential solutions are discussed.
现在人们普遍认为积极的情感状态是动物福利的一个关键组成部分。判断偏差测试是一种广泛使用的工具，用于评估动物的乐观/悲观态度，以及评估它们的情绪状态和福利。判断偏差测试已经在狗（Canis familiaris）身上使用了多次，在大多数情况下，使用的是一种空间测试，在一个位于相对积极的训练位置（P）和相对消极的训练位置（N）之间的模糊位置放置一个碗，P 位置放有诱饵碗，N 位置放有空碗。在模糊位置接近碗的潜伏期是狗对正/负结果的预期的指标。然而，这些测试的结果往往没有定论。在本研究中，对 51 只收容所狗和 40 只宠物狗的判断偏差测试表现进行了深入分析。结果表明，收容所的狗比宠物狗表现出更悲观的行为方式。然而，只有在分析到达地点的原始潜伏期而不是更常用的调整得分（即平均潜伏期值）时，才能检测到这两个群体之间的差异。此外，还发现了几个方法上的注意事项。首先，有相当比例的狗没有通过训练阶段，这可能是由于实验范式不完全适合这种物种。其次，结果显示，狗对训练地点的反应存在很高的个体内变异性，即狗的反应在整个测试中不一致，这表明动物可能没有完全学会地点和结果之间的联系。第三，狗对相邻地点的反应并不总是不同，这使人怀疑动物是否有能力区分地点。最后，从分析中出现了研究人员的存在对狗的表现的潜在影响。讨论了这些发现的意义和潜在的解决方案。
