Forgetting

What is the Meaning of Forgetting in Psychology?

Forgetting occurs when we are unable to recall information that was previously stored in memory. Forgetting can affect information stored in the long-term, short-term or sensory memory systems.

Types of Forgetting in Psychology

Ebbinghaus was one of the first researchers to look at the mechanisms of forgetting. Ebbinghaus's forgetting curve theory describes that when we first develop a new memory, within the first couple of days, details of the memory are easily forgotten. After some time, the rate of forgetting levels off, allowing us to retain some initially learned information.

Forgetting long-term memories is likely caused by different mechanisms to forgetting short-term memories. The decay theory proposes that forgetting occurs when a memory is lost due to forgetting over time. In contrast, the interference and retrieval failure theories propose that memory may be irretrievable because a memory was not moved from the short-term to the long-term memory system. This may be because the short-term memory system has a limited capacity and duration.

Theories of Forgetting in Psychology

We will now describe the key mechanisms of forgetting proposed by different theories.

Displacement

Displacement occurs when information stored in short-term memory is forgotten and lost. This occurs due to the capacity limits of short-term memory. We can only store 5-9 chunks of information in the short-term memory store, any information beyond it will be either displaced (forgotten) or transferred to long-term memory if elaborately rehearsed.

Decay

The theory of trace decay proposes that memories that are not strengthened decay over time. Memories are imprinted in neural pathways, which can be called memory engrams. Over time the pathways which have not been active in a while become weaker. As the pathway fades, it can become more difficult to access the memory, or it may disappear completely. In contrast, pathways which are strengthened by repetition become stronger, and the memory is easier to access.

This theory focuses on the impact of time on forgetting. The more time passed between memory formation and retrieval, the weaker the memory trace becomes. Therefore, the memory is likely to be forgotten. The issue with this theory is that it is difficult to test empirically. Testing memory usually relies on self-report techniques or tests, although imaging techniques are often also used. Memory tests' reliability and validity are often raised, and these cannot measure memory traces.

Interference

Interference occurs when we cannot remember the target memory because of other similar information that interferes with accessing it. Interference occurs because the cues associated with the target memory (the one you want to access) have also become associated with other similar memories.

Underwood (1957) found that research investigating similar words was less likely to be recalled. Proactive interference can explain these results. Participants may find it difficult to retrieve the words because the new memory may be confused with previous memories.

Baddeley and Hitch (1977) asked rugby players to recall the names of the teams they had played against in the season. Players' memory of a particular team they had played against was worse the more games they played. Participants who played more games were worse at recalling their competitor's team names. The results suggest that learning new information was disrupted by older memories. In essence, this is retroactive interference.

Interference makes it difficult to access the memory you wish to remember. The memory is not lost but difficult to access, freepik.com/jcomp

Retrieval failure

Retrieval is the process of remembering. Retrieval failure occurs when we are unable to access stored information because of a lack of cues. This theory proposes that the forgotten information is still in our memory, but we need some additional help to be able to remember it. Recall can be facilitated by appropriate external or internal cues that help us access the target memory.

When retrieval failure occurs due to the lack of appropriate external cues, we refer to it as context-dependent forgetting. Memories are associated with many contextual factors that were present at the time when we encoded them. These contextual factors can include what we saw, what we heard, or how we felt. The presence of the same contextual factors at retrieval may therefore be helpful for accessing and activating the target memory.

In the study of Godden and Baddeley (1975), divers learned word pairs either while in the water or on the land. They performed best at recalling the word pairs when tested in the same environment where they learned them. Similarly, Grant et al. (1998) found that students who learned information in a noisy environment performed better in a quiet environment and students who learned in a quiet environment performed better in a quiet one.

According to research, students will perform better in exams when the exam conditions match the environment that they revised in, freepik.com/pch.vector

State-dependent forgetting occurs due to the difference between your internal state at encoding and retrieval.

Carter & Cassaday (1998) tested participants' performance on different memory tasks. During the encoding stage, half of the participants were given an antihistamine drug (with sedative effects), and half were given a placebo. They found that participants performed best if their internal state at encoding matched the one at retrieval. Participants that learnt the information while sedated performed better when sedated, and participants that were given a placebo at encoding performed better on memory tasks when unaffected by the antihistamine.

Causes of forgetting in psychology

There are different possible causes of forgetting that can affect memory at different stages of its life. First, if a memory is not transferred from short-term to long-term memory, it will be quickly lost; this process is called displacement.

Once the memory is transferred to long-term memory, its trace may fade and decay over time, as proposed by the trace decay theory of forgetting. The memories become weaker and eventually are lost, and therefore we cannot remember them anymore.

Natural Forgetting in Psychology

Learning is a dynamic process, and forgetting is a natural part of it. Natural forgetting might be annoying at times, but it's generally unproblematic. It can be considered a natural form of neuroplasticity, a consequence of our brain rewiring and adapting to the environment. As we discussed, this kind of natural forgetting can occur due to decay, interference or lack of appropriate cues.

However, in some cases like Alzheimer's disease or amnesia, forgetting can be a sign of pathology. These conditions are associated with brain damage that impairs our long-term memory to a greater extent than normal forgetting does.