Theories of Forgetting
| For this section you need to be able to:
(a) Describe and evaluate the Cue Dependent Theory of Forgetting (Tulving, 1974) and one other theory of forgetting. The theory we have chosen is Trace Decay theory of forgetting. (b) Describe and evaluate in detail Godden and Baddeley’s (1975) study of cue dependent forgetting/memory and one other study of memory or forgetting in the Cognitive Approach. The study we have chosen is Craik and Tulving’s (1975) Levels of processing study which can be found on the memory page. |
Forgetting is defined as the experience of not being able to recall information, such as an event, fact or a person’s name.
There are many theories of forgetting although a distinction can be made between availability theories and accessibility theories.
Availability theories propose that memories are forgotten because they have been permanently lost from the brain. For example, trace decay theory argues that memories are forgotten because the physical trace left in the brain of a memory disappears over time. Availability theories are mainly used to explain forgetting in short term memory.
Accessibility theories propose that memories still exist but are difficult to retrieve. For example, cue –dependency theory argues that we forgetting occurs when we have the information we are seeking in our memory but lack the cues to access it. Accessibility theories are mainly used to explain forgetting in long term memory.
Cue- dependency theory of forgetting
According to Tulving (1975) cue dependent forgetting occurs when we have stored information but cannot access it because we lack the necessary cues to retrieve it. This theory argues that when we encode information we also encode details of the context and state that we were in at the time of encoding. These encoding cues act as additional information that guides us to the information that we are trying to retrieve. Without these cues we struggle accessing the information.
Tulving identified two types of cues; context cues and state cues.
Context dependent cues are those cues from the external environment which improve the retrieval of memories. That is, improved recall of information occurs when the context present at encoding and retrieval are similar. Context cues might include such things as smells, sounds and of course visual cues.
State dependent cues are those cues from our internal physiological state which are present when learning takes place. That is improved recall of information occurs when the emotional state present at encoding and retrieval are similar. State dependent cues might include emotions and states such as happiness, sadness, excited, afraid or even drunk.
Here is the evaluation of cue dependency theory of forgetting
Godden and Baddeley (1975) Context-dependent memory in two natural environments: on land and under water
Aim
The aim of this study was to investigate the effect of environmental encoding cues on the ability to recall. In particular Godden and Baddeley wanted to investigate the role of context cues and test cue-dependency theory which argues that recall will be better if it takes place in the same environment as learning.
Procedure
Eighteen participants were recruited from a university diving club in Scotland. There were 13 male and 5 female participants and all participants used their own SCUBA equipment.
The field experiment was carried out over 4 days.
The 18 participants were randomly divided into four groups and all participants took part in all 4 conditions.
The type of experimental design used was therefore a repeated measured design.
During the course of the diving holiday each participant undertook one condition per day.
1. Learn on land and recall on land (dry/dry)
2. Learn under water and recall underwater (wet/wet)
3. Learn on land and recall underwater (dry/wet)
4. Learn under water and recall on land (wet/dry)
The independent variables were therefore whether the learning and recall environments were the same (dry/dry or wet/wet) or different (dry/wet or wet/dry).
The participants listened to the words on land and 20 feet under water. Underwater the divers were weighted so they could sit on the bottom. On land the divers sat at the water’s edge with their SCUBA equipment on but without their breathing masks on.
A different word list was used for each condition of the experiment and each list comprised of 36 unrelated words, 2-3 syllables long. The words were selected at random from a word book.
The word lists were recorded onto tapes and the divers wore Diver Underwater Communication devices enabling them to hear the tape recorded words and instructions.
The words were presented in blocks of 3 with a 4 second gap in between each block in order for the participants to breathe as using the breathing apparatus would have been noisy thus hampering their ability to hear the words.
The word lists were each presented twice and after the second presentation there was a 4 minute gap and an interference task whereby the participants heard 15 numbers which they had to write down.
Participants were then given 2 minutes (using a pencil and plastic covered board) to write down as many words as they could remember. The number of correctly recalled words was therefore the dependent variable.
Results
The results show that words learnt and recalled in the same environment were better remembered.
For example, when participants learnt and recalled on dry land the mean number of words recalled was 13.5 and similarly when participants had to learn and recall in the water the mean score was 11.4.
The mean number of words recalled was much lower when the learning and recall environments were different. For example, the mean score for learning in the wet condition and recalling in the dry condition was only 8.5.
Conclusion
Godden and Baddeley concluded that their results do support the claims of cu-dependency theory.
They demonstrated that cues from the environment do aid memory and that forgetting occurs when there is a lack of the same cues in the environment at recall.
Here is the evaluation of the Godden and Baddeley study
Here is a quick multi-choice quiz on cue dependency and the Godden and Baddeley study Quizcuedependency
Trace Decay Theory of Forgetting
According to trace decay theory forgetting occurs as a result of decay in memory pathways in the brain. Memories are formed in the brain when neurones make connections with each other so that when one neurone is activated others in the link are automatically activated too. This pattern of activation is called a memory trace.
This creation of new links between neurones causes a physical change within the brain structure and this physical change is known as an engram.
Trace decay theory argues that forgetting occurs when a memory is not actively used the physical trace between neurons begins to fade away and may be over-written by new memories.
Therefore by actively accessing a memory we strengthen the trace and the memory should still be available.