Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, 2357 Main Mall, Vancouver, BC, V6T 1Z6, Canada.
Department of Clinical Studies, Swine Teaching and Research Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA.
Sci Rep. 2023 Apr 7;13(1):5679. doi: 10.1038/s41598-023-32756-5.
In humans, the 'peak-end' rule states that recollection of an experience is most often influenced by the peak (the most intense moment) and end of the experience. We investigated whether calves followed the peak-end rule in their memory of a painful procedure: disbudding. As proxies for retrospective and 'real-time' reports of pain, we used conditioned place aversion, and reflex pain behaviours. In two separate trials, calves were subjected to two disbudding conditioning sessions (one horn per treatment), acting as their own control. In the first trial, calves (n = 22) were disbudded and remained in a pen for 4 h, and disbudded and left in another pen for 4 h with an additional 2 h following an analgesic treatment. In the second trial, calves (n = 22) were disbudded and left in pens for 6 h during both treatments, receiving the analgesic at either 2 h or 4 h after disbudding. Calves were then tested for place aversion. For both trials we did not observe a preference for the pens where calves received analgesic treatment towards the end of the session. We did not find an association between aversion and the sum, peak or end of pain behaviours. Results are not consistent with a peak-end effect in calves' memory of pain.
在人类中，“峰值-终点”规则表明，对体验的回忆通常受体验的峰值（最强烈的时刻）和终点的影响最大。我们研究了小牛是否遵循“峰值-终点”规则来记忆痛苦的过程：去角。我们使用条件性位置厌恶和反射性疼痛行为作为疼痛的回顾性和“实时”报告的替代指标。在两个独立的试验中，小牛（n=22）接受了两次去角的 Conditioning 处理（每个处理一个角），作为自身对照。在第一次试验中，小牛（n=22）去角后在一个围栏中停留 4 小时，另一个围栏中去角后在一个围栏中停留 4 小时，并在镇痛治疗后额外停留 2 小时。在第二次试验中，小牛（n=22）在两个处理中都在围栏中停留 6 小时，在去角后 2 小时或 4 小时接受镇痛治疗。然后对小牛进行位置厌恶测试。对于这两个试验，我们都没有观察到小牛在结束时对接受镇痛治疗的围栏有偏好。我们没有发现厌恶与疼痛行为的总和、峰值或终点之间存在关联。结果与小牛对疼痛的记忆中的“峰值-终点”效应不一致。
