A new look at memory retention and forgetting.

The forgetting curve is one of the most well known and established findings in memory research. Knowing the pattern of memory change over time can provide insight into underlying cognitive mechanisms. The default understanding is that forgetting follows a continuous, negatively accelerating function, such as a power function. We show that this understanding is incorrect. We first consider whether forgetting rates vary across different intervals of time reported in the literature. We found that there were different patterns of forgetting across different time periods. Next, we consider evidence that complex memories, such as those derived from event cognition, show different patterns, such as linear forgetting. Based on these findings, we argue that forgetting cannot be adequately explained by a single continuous function. As an alternative, we propose a Memory Phases Framework, through which the progress of memory can be divided into phases that parallel changes associated with neurological memory consolidation. These phases include (a) Working Memory (WM) during the first minute of retention, (b) Early Long-Term Memory (e-LTM) during the 12 hr following encoding, (c) a period of Transitional Long-Term Memory (t-LTM) during the following week or so, and (d) Long-Lasting Memory (LLM) memory beyond this. These findings are of significance for any field of study where being able to predict retention and forgetting is important, such as training, eyewitness memory, or clinical treatment. They are also important for evaluating behavioral or neuroscientific manipulations targeting memories over longer periods of time when different processes may be involved. (PsycInfo Database Record (c) 2022 APA, all rights reserved).