Forgetting involves the loss of information over time; however, we know little about what form this information loss takes. Do memories become less precise over time, or do they instead become less accessible? Here we assessed memory for word–location associations across four days, testing whether forgetting involves losses in precision versus accessibility and whether such losses are modulated by learning a generalizable pattern. We show that forgetting involves losses in memory accessibility with no changes in memory precision. When participants learned a set of related word–location associations that conformed to a general pattern, we saw a strong trade-off; accessibility was enhanced, whereas precision was reduced. However, this trade-off did not appear to be modulated by time or confer a long-term increase in the total amount of information maintained in memory. Our results place theoretical constraints on how models of forgetting and generalization account for time-dependent memory processes.

忘记会随着时间的流逝而丢失信息。但是，我们对这种信息丢失所采取的形式知之甚少。记忆会随着时间的流逝变得不那么精确，还是变得难以获得？在这里，我们评估了为期四天的单词-位置关联的记忆，测试了遗忘是否涉及精度与可访问性的损失，以及这种损失是否通过学习可概括的模式进行了调整。我们表明，遗忘涉及到内存可访问性的损失，而内存精度没有变化。当参与者学习到一组符合一般模式的相关单词位置关联时，我们看到了一个很大的权衡；可访问性得到了增强，而精度却降低了。然而，这种权衡似乎并没有受到时间的影响，也没有使内存中保存的信息总量长期增加。我们的结果对遗忘和泛化模型如何解释与时间有关的存储过程提出了理论约束。