Uh-oh! You can't seem to find your phone. Or perhaps you've forgotten your email password (yet again). We've all been there. The good news is that forgetting is an inevitable part of life. But why do we forget, anyway? What are the factors affecting forgetting in psychology? Read on to find out.
- This explanation starts with the definition of forgetting in psychology.
- Next, the causes of forgetting in psychology are presented.
- Then, the explanation reviews theories of forgetting in psychology.
- The types of forgetting in psychology are also discussed.
- And last, the factors affecting forgetting in psychology are presented.
Define Forgetting in Psychology
According to the American Psychological Society, forgetting in psychology refers to the inability to remember something previously learned.
Forgetting is indeed expected in all humans, but certain types of forgetting are not. These are called pathological forgetting, which refers to the forgetting that can be described in diagnostic terms.
Amnesia is a form of forgetfulness in which a patient can no longer remember some information. Amnesia can happen as a consequence of experiencing brain damage, drug abuse or traumatic experiences.
Causes of Forgetting in Psychology
Why do we forget things? It seems like a simple question, but psychologists have invested decades of research in answering it. Two main factors are considered to cause forgetting: brain damage and interference.
Forgetting in Psychology: Brain Damage
Henry Molaison (HM) was a patient who got a lobotomy of his brain performed to cure epilepsy he suffered from. As part of the lobotomy, his hippocampus and amygdala were removed. The surgery successfully prevented HM from later suffering epilepsy symptoms. However, after surgery, HM was not able to form new memories.
Scoville and Milner (1957) conducted a study to test brain surgery's effects on HM's memory. Researchers detected severe anterograde amnesia in HM. The study concluded that damage to the hippocampus structure is related to anterograde amnesia.
Anterograde amnesia is memory loss that affects an individual's ability to create memories after brain surgery. However, the memories formed before the brain surgery remain intact.
Forgetting in Psychology: Interference
The second cause for forgetting that psychologists have described is interference. This refers to the forgetting that happens when memories disturb one another.
In 2009, Ellenbogen and other researchers designed a study to test whether learning a list of works would affect learning another list of words.
Participants were asked to learn a list of words called the A-B list. Participants were tested on their recalling of the list 12 hours later. After the test, participants were asked to learn another list of words called A-C. The A-C list's first word was the same as the first one in the A-B list. Every other word, however, was different.
Even if participants only invested 10 minutes learning the A-C list, their scores dropped significantly when they were tested on the A-B list again. This was taken as evidence that new learning interferes with previous learning.
These findings lead to the development of a theory of forgetting. Let's take a look at it.
Theories of Forgetting in Psychology
Forgetting is the loss of information from the long-term memory store. Several theories have been proposed to explain why these occur.
Forgetting in Psychology: Interference Theory
The interference theory of forgetting in psychology explains the causes of forgetting in long-term memory (LTM).
According to the interference theory, forgetting occurs when two pieces of information conflict.
The theory suggests that when information is being processed to be memorised, it can be mixed with other information, resulting in memory distortion and disruption. Interference is more likely to happen if the memories are similar.
Time of learning also affects the likelihood of inference. Interference is less likely to occur when there is a large gap between learning instances. Furthermore, the theory described two different types of interference in forgetting.
Forgetting in Psychology: Trace Decay Theory
The trace decay theory explains forgetting in short-term memory.
According to the trace decay theory, forgetting occurs due to the automatic decay of memory.
Short-term memory can only keep information for a given period (usually between 15 and 30 seconds). If such information is not rehearsed, then such information decays and is no longer able to be remembered.
Evidence of the trace decay theory comes from a laboratory experiment conducted by Peterson and Peterson in 1959. In this study, participants had to learn trigrams one at a time in intervals of 3, 6, 9, 12, 15 and 18 seconds.
Trigrams are combinations of three letters that are not real words, such as TBU, PLF or MNW.
After learning each trigram, participants were asked to count a number backward in threes or fours until a light appeared on the screen. After the presentation of the light, the participant would recall the trigram. This was included to prevent rehearsal.
The results indicated that the shorter the interval between learning and recalling was, the better the performance. After 3 seconds, around 80% of the trigrams were recalled, while after 18 seconds, only 10% were recalled.
Researchers concluded that short-term memory lasts around 18 seconds, after which forgetting occurs.
Fig. 1. Forgetting is when an individual can no longer retrieve information that the memory stores previously encoded.
Types of Forgetting in Psychology
There are different types of forgetting. These types emerge based on the other causes of such memory loss. When forgetting occurs due to interference, the forgetting can either be proactive or retroactive.
Forgetting in Psychology: Proactive Interference
Proactive interference (PI), in simple words, reflects that what we have already known previously interferes with information we recently learned, leading to forgetting new memory.
Have you ever confused your old password with your new one? Or have your teachers ever mixed up students' names with those from previous school years? These are examples of PI.
Forgetting in Psychology: Retroactive Interference
Retroactive interference (RI), differently, reflects the forgetting that takes place when the new information interferes with the old one.
The information we recently learned interferes with what we already know, which leads to forgetting old memory.
Have you ever failed to remember your old postcode because you now remember your current one? Or have you ever started to learn a new language that affects the memories of your mother tongue? This is due to RI.
Memory loss is called amnesia, when forgetting occurs due to brain damage. Amnesia can either be anterograde or retrograde.
Forgetting in Psychology: Anterograde Amnesia
Anterograde amnesia is memory loss that affects an individual's ability to create memories after brain surgery. However, the memories created before the brain surgery remain intact.
Forgetting in Psychology: Retrograde Amnesia
Anterograde amnesia is memory loss that affects an individual's ability to create memories before brain surgery. The individual, however, can learn new things and skills after such brain surgery.
Factors Affecting Forgetting
Psychologists have identified factors that affect forgetting. These factors are context and state. In this way, there exist context-dependent memories and state dependent-memories.
Forgetting in Psychology: Context-Dependent Memories
Maybe it has happened to you that you turn into the pantry and ask yourself: what was I getting from here? You forgot why you went there or what you were getting. This is an example of how context can affect forgetting.
Context-dependent memory refers to the positively remembered information in a given environment.
According to the context theory of forgetting, memories can be context-dependent. And changing such context can induce forgetting.
Tulving (1974) stated that when humans learn information, they also learn details about the environment in which the learning took place.
Putting this idea under investigation, Godden and Baddeley (1975) designed a study with divers to test whether people would remember better if the information was tested in the same context where it was learned. To do this, they asked a group of divers to memorise a list of words underwater or on a beach.
The participants were split into four groups:
- Learn words underwater and recall words underwater
- Learn words underwater and remember words on the beach
- Learn words on the beach and remember words on the beach
- Learn words on the beach and remember words underwater
It was found that the participants were able to recall the words more accurately when they learned the terms, and the place they recalled the words was the same. And they were significantly less accurate when the two contexts didn't match.
The results support the idea that context plays a role in forgetting.
Fig. 2. Godden and Baddeley (1975) recruited divers in their study.
Forgetting in Psychology: State-Dependent Memories
These are memories that are triggered by a specific state or mood that a person is in. For example, you may be reminded of your dog passing away when you are experiencing a sad moment, compared to when you are happy.
Goodwin and colleagues studied this in 1975. They conducted a study that tested whether participants' states affected their forgetting of words. To test the state dependency, they used alcohol. Participants were asked to learn a list of words one day and were tested the day after. Four experimental groups emerged:
Group 1: Participants were sober on the day of the learning and the day of the recalling.
Group 2: Participants consumed alcohol during learning and recall days.
Group 3: Participants consumed alcohol on the learning day and were sober on the recalling day.
Group 4: Participants were sober on the learning day and consumed alcohol on the recalling day.
The results indicated that individuals in groups 1 and 2 performed better than those in groups 3 and 4. The best performance, however, was the one from individuals in group 1. These results can be interpreted as evidence favouring state dependency on memories.
Forgetting in Psychology - Key takeaways
- Research has attempted to define forgetting in psychology and what contributes to the loss of memories.
- The causes of forgetting in psychology have been linked to brain damage and interference.
- Types of forgetting in psychology include anterograde, retrograde amnesia, and proactive and retroactive interference.
- The theories of forgetting in psychology include the interference and trace decay theory.
- Theories have been put forward to explain factors affecting forgetting, such as state-dependent and context-dependent theories.
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