Chronic stress induces pessimistic-like judgment and learning deficits in sheep

摘要: Chronic stress can be described as a long-term negative affective state induced by an accumulation of emotional experiences that alters individual's interactions with the environment. In humans, chronic induces both persistent judgment biases and learning deficits. We investigated whether similar cognitive could occur in sheep. Twenty-four lambs were subjected to treatment for 9 weeks (exposure various unpredictable, uncontrollable aversive events regularly encountered ordinary agricultural practices) 24 other used control group. Before all had been trained approach or avoid food bucket depending on its location. After treatment, individually exposed two tests: (i) approach/avoidance test, testing response ambiguous locations bucket, i.e. bias (ii) test consisting training six consecutive days distinguish between visual stimuli differing their color shape (acquisition phase) re-exposure conditions 2 after end acquisition phase (recall phase). treated took longer bucket. During lower numbers correct choices than recall phase. Hence sheep experiencing repeated demonstrated pessimistic-like These may useful measures assess states animals.