Trace decay: Do your memories fade with time?
痕迹减退：你的记忆随时间减退吗？
The most basic explanation of forgetting has to do with the passage of time. Our memory traces are stored in living tissue, which inevitably changes over time. It is a well-known fact that connections between neurons deteriorate over time and as a consequence, the memory traces stored within these connections decay.
关于遗忘最根本的解释与时间的流逝有关。我们的记忆痕迹存储在活组织中，因此不可避免地随时间而变化。众所周知，神经元之间的联结会随时间而衰退，结果就是存储在这些联结中的记忆痕迹随之变浅。
In addition, there is another possible cause for the decay of our memories. Surprisingly, making new memories may be part of the reason we forget. As new memories are formed, new neurons are produced in the hippocampus (the memory hub), which changes its structure and patterns of connections. As a consequence, older memories are more difficult to retrieve.
此外，记忆的减退还有另一个可能的原因。令人惊讶的是，记住新东西或许正是导致我们遗忘的部分原因。随着新的记忆形成，海马体（大脑的记忆中枢）会产生新的神经元，这会改变已有联结的结构和模式。结果，旧的记忆也就更难被检索到了。
Therefore, if you need to retain old information in memory (for a final exam for instance), it would be a good idea to revise it again while you are studying something new, otherwise the old information might be superseded by the new information.
因此，如果你需要在记忆中保留旧信息（比如为了期末考试），学了新东西之后再复习一下旧有的内容可能会是个好主意，否则旧信息可能会被新信息取代。
We recommend that you establish a schedule of revision of the old material (even a couple of minutes every day should suffice) that is interspersed with the study of the new material. This is especially important if you study several different subjects/topics within one day because you memory cannot yet benefit from protective sleep-induced consolidation processes. There is another reason why studying new things can impair the retrieval of old things and we discuss it in the section “interference”.
我们建议你设定一个复习旧内容的日程表（即使每天只花几分钟时间就够了），穿插在学习新内容的过程中。如果你一天之内学习好几个不同的科目/主题，这样做就尤其重要了，因为你的记忆还来不及得到睡眠引发的固化过程的保护。学习新东西会损害对旧内容的检索还有另一个原因，我们会在“干扰”一节讨论。
In summary, we recommend the following
总结起来，我们推荐以下做法：
·Spend about 1/10 of your study time revising old material
·花大约十分之一的时间复习旧内容。
·Insert brief periods of revision of old material into the study of new material
·在学习新内容的过程中，穿插对旧内容的简短回顾。
——节选自《记忆的科学》
