What is the duration of long-term memory?

Long-term memory is characterized by its capacity to store information for extended periods, potentially lasting a lifetime. The correct explanation for why long-term memory is said to last indefinitely but decays over time lies in the understanding of how memories are formed and retained.

In long-term memory, information is stored through various processes, including encoding, consolidation, and retrieval. Once information is successfully encoded into long-term memory, it can remain accessible for many years. However, this does not mean that it is immune to change or decay. Over time, memories can become less vivid or can even be altered due to forgetting, interference, or other factors that affect recall. This phenomenon is often referred to as memory decay, where the strength of the memory weakens, although the information itself may still be retrievable in some form.

Thus, the idea that long-term memory can last indefinitely while still being subject to decay captures the complexity of how memories are maintained and accessed throughout a person's life. This highlights the dynamic nature of memory, where long-term storage is not simply a static repository but rather a system that is influenced by various cognitive processes.