When a memory of a past experience is not activated for days or months, forgetting tends to occur. Yet it is erroneous to think that memories simply fade over time—the steps involved are far more complex. In seeking to understand forgetting in the context of memory, such auxiliary phenomena as differences in the rates of forgetting for different kinds of information also must be taken into account.
It has been suggested that, as time passes, the physiological bases of memory tend to change. With disuse, according to this view, the neural engram (the memory trace in the brain) gradually decays or loses its clarity. While such a theory seems reasonable, it would, if left at this point, do little more than restate behavioral evidence of forgetting at the nervous-system level. Decay or deterioration does not seem attributable merely to the passage of time; some underlying physical process needs to be demonstrated. Until a neurochemical basis for memory can be more explicitly described, any decay theory of forgetting must await detailed development.
Reasons for Forgetting * Retrieval Failure * Interference * Failure to Store * Motivated Forgetting
Retrieval Failure
Have you ever felt like a piece of information has just vanished from memory? Or maybe you know that it's there, you just can't seem to find it. The inability to retrieve a memory is one of the most common causes of forgetting. One possible explanation retrieval failure is known as decay theory. According to this theory, a memory trace is created every time a new theory is formed. Decay theory suggests that over time, these memory traces begin to fade and disappear. If information is not retrieved and rehearsed, it will eventually be lost.
Inference
A prominent theory of forgetting at the behavioral level is anchored in the phenomenon of interference, or inhibition, which can be either retroactive or proactive. In retroactive inhibition, new learning interferes with the