Jensen R A, Riccio D C, Gehres L
Physiol Behav. 1975 Aug;15(2):165-9. doi: 10.1016/0031-9384(75)90231-0.
Two experiments examined the extent to which retrograde amnesia (RA) is attenuated by prior learning experiences. In Experiment 1, rats initially received either passive avoidance training in a step-through apparatus, exposure to the apparatus, or noncontingent footshock. When training on a second but different passive avoidance task was followed by hypothermia treatment, RA was obtained only in the latter two groups. In Experiment 2, one-way active avoidance training, yoked noncontingent shocks, or apparatus exposure constituted the initial experience. Subsequent step-down passive avoidance training and amnestic treatment resulted in memory loss for the prior apparatus exposure group, but not for either of the preshocked conditions. These experiments demonstrate that certain types of prior aversive experience can substantially modify the magnitude of RA, and, in conjunction with other familiarization studies, emphasize a paradox for interpretations of RA based solely upon CNS disruption. The possibility that hypothermia treatment serves as an important contextual or encoding cue necessary for memory retrieval was considered. It was suggested that prior experience may block RA by enabling rats to differentiate training and treatment conditions.
两项实验研究了逆行性遗忘（RA）在多大程度上会因先前的学习经历而减弱。在实验1中，大鼠最初要么在穿梭箱中接受被动回避训练，要么接触该装置，要么接受非条件性足部电击。当在第二个但不同的被动回避任务上进行训练后进行低温治疗时，仅在后两组中出现了逆行性遗忘。在实验2中，单向主动回避训练、配对非条件性电击或装置接触构成了最初的经历。随后的逐步被动回避训练和遗忘处理导致先前接触装置组出现记忆丧失，但在两种预电击条件下均未出现。这些实验表明，某些类型的先前厌恶经历可以显著改变逆行性遗忘的程度，并且与其他熟悉化研究一起，强调了仅基于中枢神经系统破坏来解释逆行性遗忘的一个悖论。研究考虑了低温治疗作为记忆检索所需的重要背景或编码线索的可能性。有人提出，先前的经历可能通过使大鼠能够区分训练和治疗条件来阻止逆行性遗忘。
