Memory in humans requires three processes, which are encoding, storage, and retrieval. The hippocampus extracts information from our environments, and moves on through these three steps. Encoding is the process of creating a memory code in order to transfer information into a storable form, by giving it an association. Storage is a physiological change, requiring the memory neurotransmitter called acetylcholine, whereupon we maintain the encoded information in our memory over a period of time. Retrieval is where the majority of memory problems occur, and is the reversal of the encoding process after lifting the information out of storage. Humans have three different types of memory: sensory memory, which lasts only a few brief seconds, short-term memory, which is currently active information. These memories can be forgotten by something called displacement, which occurs when short-term memory is full. Long-term memory is the third type, which is an unlimited capacity storage space, and is the most permanent level of storage.
This includes declarative (semantic and episodic memory) and nondeclarative memory.
Forgetting is classified as the loss of information over a period of time. There have been several different theories put forward as to how we forget. Here we will be focussing on four main concepts of forgetting: decay, interference, repression, and retrograde amnesia.
Decay is a theory which states that unused short-term memory traces disintegrate over time. The likelihood of forgetting is increased as the period between learning and retrieval increases. This was first demonstrated by Ebbinghaus (1885), who studied his own memory.
Ebbinghaus created a forgetting curve to illustrate the loss of information from his long-term memory over a period of time. This clearly showed that decay in memory did occur as time passed, with forgetting occurring swiftly to begin with, but later slowing down and levelling out. This suggests that...