Holmes Nathan M, Westbrook R Frederick
School of Psychology, University of New South Wales, Sydney NSW 2052, Australia.
School of Psychology, University of New South Wales, Sydney NSW 2052, Australia
Learn Mem. 2014 Oct 15;21(11):597-605. doi: 10.1101/lm.035089.114. Print 2014 Nov.
Four experiments used rats to study appetitive-aversive transfer. Rats trained to eat a palatable food in a distinctive context and shocked in that context ate and did not freeze when tested 1 d later but froze and did not eat when tested 14 d later. These results were associatively mediated (Experiments 1 and 2), observed when rats were or were not food deprived (Experiments 1 and 2), and were not due to latent inhibition (Experiment 3). In contrast, rats trained to eat in the context and shocked there 13 d later froze and did not eat when tested 1 d after the shocked exposure. However, rats that received an additional eating session in the context 1 d before the shocked exposure ate and did not freeze when tested 1 d after the shocked exposure (Experiment 4). The results show that appetitive conditioning transiently interferes with aversive conditioning. They are discussed in terms of a weak context-shock association becoming stronger with the lapse of time (so-called fear incubation) or of the interference by the context-food association becoming weaker with the lapse of time.
四项实验用大鼠研究了食欲-厌恶转移。训练大鼠在一个独特环境中进食一种美味食物，并在此环境中遭受电击，1天后测试时，大鼠进食且未出现僵住反应，但14天后测试时，大鼠僵住且未进食。这些结果是由联想介导的（实验1和2），无论大鼠是否处于食物剥夺状态均可观察到（实验1和2），且并非由于潜伏抑制（实验3）。相比之下，训练大鼠在此环境中进食，13天后在此遭受电击，电击暴露1天后测试时，大鼠僵住且未进食。然而，在电击暴露前1天在此环境中额外进行一次进食的大鼠，在电击暴露1天后测试时进食且未僵住（实验4）。结果表明，食欲条件作用会短暂干扰厌恶条件作用。这些结果从随着时间推移弱的环境-电击关联变得更强（所谓的恐惧潜伏期延长）或环境-食物关联的干扰随着时间推移变得更弱的角度进行了讨论。
