- Created by: Drageemily
- Created on: 31-10-18 16:57
Types of Encoding
Encoding: the changing of information so it can be stored in the brain.
There are four main types of encoding:
Acoustic: How something sounds
Semantic: The meaning of something
Visual: How something looks
Tactile: How something feels
Encode - store - retrieve
Encoding: The form information takes when we put it into our memory so that it can be held in our brain
Storage: Holding information in our memory until it is needed
Retrieval: The process of accessing information that has been stored in the brain
There are three main types of retrieval:
Recognition: identifying a piece of information from a number of options
Cued recall: being given a clue to help you remember
Free recall: remembering something without any help
A study on Encoding
Baddeley's study on encoding:
Aim: To see if there was a difference in the type of encoding used in STM and LTM
Method: Four groups were given 12 sets of 5 words to remember. G1 had similar sounding words, G2 had dissimilar sounding words, G3 had words with similar meanings, G4 had words with dissimilar meaning.
G1 and G2 asked to recall straightaway, whilst G3 and G4 asked to recall words after 20 mins.
Results: G1 recalled fewer than G2. G3 recalled fewer than G4.
In STM words with similar sounds more poorly recalled than words with different sounds.
In LTM words with similar meanings more poorly recalled than words with different meanings.
Conclusion: Shows STM encodes by sound. LTM encodes by meaning.
Evaluation for a study on encoding
Controlled Experiment: Strength. Done in a laboratory study, extraneous variables controlled.
For example, the hearing was controlled by giving participants a hearing test.
Therefore, more certain that the type of words used was the factor that affected ppt's recall.
STM is sometimes visual: Weakness. Encoding in STM not always involves sound.
Other studies have found that if pictures are recalled rather than words then visual encoding is used.
Suggests that info doesn't just go into STM in acoustic form.
LTM may not have been tested: Weakness. LTM may not have been tested in this study.
Waiting 20 mins before recall doesn't mean that the words are in the LTM.
May mean that the conclusion that LTM encodes semantically lacks validity.
Different types of encoding
Long-term memory: These memories last for weeks, months, years or even a lifetime.
There are three types of LTM:
Episodic memory: Memory for events/what you have done
Semantic memory: Memory about what things mean.
Procedural memory: Memory of how you do things. (unconscious recall)
Declarative: Episodic and semantic, require conscious thought to recall
Non-declarative: Procedural, doesn't require conscious thought to recall
Evalution for the different types of memory
Specific locations in the brain: Strength. Brain scans show that different LTM relates to different brain areas.
For example, episodic found in the right prefrontal area, semantic associated with the left prefrontal area, procedural associated with the motor area.
Suggests that there are different types of LTM.
Patients with amnesia: Strength. Supported by patients with amnesia.
For example, Clive Wearing lost most of his episodic but not his procedural as he could still play the piano
Shows that there are different types of LTM.
It's not that simple: Weakness. Distinctive types of LTM are difficult to separate.
Isn't a clear difference between episodic and semantic memories because these are normally a mixture of types.
Therefore, having separate types of LTM may be an oversimplification.
The multistore model
States there are three memory stores (Sensory, STM, LTM) each with their own different duration, encoding and capacity (DEC). Info moves between these stores either through attention or rehearsal.
Sensory memory holds info from senses for a short time, large capacity. Paying attention transfers info to STM.
STM: Temporary memory store with a limited capacity of between 5 & 9 items/chunks of info lasting 30 seconds.
Role of rehearsal: Verbal repetition keeps info in STM.
If the info is rehearsed for long enough it is transferred into LTM.
LTM: Encoded by meaning, permanent memory store with an unlimited capacity and info can be stored up to a lifetime.
Evaluation of the Multistore model
Research support: Strength. Support for the existence of different memory stores. Baddeley's study shows STM and LTM encode info differently. Therefore, the two types have qualitative differences.
Simple model:Weakness. Model is too simple suggesting we only have one STM and one LTM. Research - STM divided into visual and acoustic stores, LTM episodic, semantic and procedural memory. Therefore, memory more complex than the model suggests.
Artificial materials: Weakness. Research suggests the model used artificial materials. For example, using word lists or consonant syllables. Therefore, the results would not illustrate all the different ways we use memory.
Murdock's study on primacy and recency effects on
Murdocks study on Primacy and recency effect.
Aim: Set out to see if serial position effect was influenced by the number of words on a list
Method: Words from 4000 most common words were chosen randomly. Ppts listened to 20 word lists with between 10 and 40 words on them. They recalled the words after each list.
Results: Recall is not affected by the number of words on a list but was related to the position of the word on the list. Murdock found higher recall for the first few words and for the last few words rather than the middle of the list.
Conclusion: Results confirm the serial position effect. Findings support MSM as the first few words were rehearsed (in LTM) and the last few words were in the STM.
Evalution for Murdock's study
Controlled lab study: Strength. Study relates to it being well-controlled. Familiarity of the words was the same throughout each list. Therefore, more certain that it was the position of the words that affected recall.
Artificial task: Weakness. Task was artificial. Lists of words relates to just on type of memory. Therefore results don't relate to how we use our memory in everyday life
Supproting research:Strength. Research on amnesia supports the conclusions of the study. Some people with amnesia can't store LTMs and do not show a primacy effect but do show a recency effect. Therefore, primacy effect is related to LTM
Bartlett's War of the Ghosts study
Aim: Investigated how memory is reconstructed when people are asked to recall an unfamiliar story - particularly from a different culture.
Method: Ppts were shown the War of the Ghosts study. They recalled it after 15 mins, then weeks, months and years. Bartlett recorded the recall.
Results: Ppts changed the story. They left out info that was less familiar. The story was shortened, phrases changed to those used in ppts own culture.
Conclusion: Study shows we use our knowledge of social situations to reconstruct memory, as details of study were invented to improve meaning.
Evaluation for Bartlett's study
Lacks control: Weakness. Lack of control. For example, ppts were not told that accurate recall as important. Other studies found recall was better when ppts were told this. Suggests recall is more accurate that Bartlett concluded.
Biased results: Bartlett's own beliefs may have affected results. He analysed the recalls himself. His belief that recall would be affected by cultural expectations may have biased the interpretation. Therefore, we can't fully trust the conclusion.
Unusual story: Weakness. Recall may not reflect everyday memory processes as these would be less affected by cultural expectations. Therefore, study telss us little about everyday memory.
Theory of reconstructive memory
People remember overall meanings of events and when retrieving info they rebuild the memory.
We do not have exact recall. Elements are missing and memories aren't accurate representations of events that took place.
We record small pieces of info in LTM. During recall we recombine them to tell the story. Each time elements are put together slightly differently.
The way info is stored and recalled is affected by social and cultural expectations.
We focus on the meaning of events and make an effort to understand the meaning to make sense of the parts of the story.
Evaluation for reconstructive memory
More realistic research: Strength. Research reflects how we use our memory in our everyday lives. The research doesn't use artificial word lists or consonant syllables. This makes the findings more relevent to real-life memory processes.
Some memories are accurate: Weakness. Not all memories are reconstructed. For example, ppts often recalled 'something black same out of his mouth' because it was quite a distinctive phrase. This shows that some memories are accurate.
Real-world application: Strength. Reconstructive memory explains problems with eye-witness testimony (EWT). Bartlett's study shows memory is affected by expectations, indicating people do not always recall accurately. Therefore, EWT is no longer solely relied on as evidence.
A study on Interference
Aim: McGeoch and McDonald aimed to see whether the accuracy of recalling a list of words would be affected by a competing list of words.
Method: Ppts learned a list of 10 words then were shown a new list. 5 different new lists: synonyms, antonyms, unrelated words, nonsense syllables, three-digit numbers and no new list.
Results: Ppts recalled initial list of words, memory was affected by the new list. The effect was strongest when the new list had words with similar meanings to the first list.
Conclusion: Shows that interference from the second set of info reduces the accuracy of memory. Interference is strongest when two sets of info are similar.
Evaluation for Interference
Controlled research: Strength. There was high control. Counter-balancing was used to reduce the impact that learning the lists in the same order would have on the results. Therefore, extraneous variables were reduced.
Artificial task: Weakness. Does not reflect real-life memory activity. Don't often have to remember lists of words or very similar things. Therefore, the conclusion about the effect of interference is limited because of its artificiality.
Not really forgetting:Weakness. Interence may not be an explantation of forgetting. Info is not forgotten but can;t be accessed because an accurate cue has not been given. Therefore, interference only appears to cause inaccurate memory.
A study on Context
Aim: Godden and Baddeley aimed to see if context improved recall. They used 'underwater' and 'on the beach' as the two contexts.
Method: Divers listened to and recalled words in the same or different settings:
Same context: dry/dry, wet/wet
Different context: dry/wet, wet/dry
Results: Recall was highest in the two matching conditions (same). They were more accurate in the environment they'd learnt in.
Conclusion: Context of learning acts as a trigger or cue when trying to remember info thus improving accuracy.
Evaluation for Context
Artificial task: Weakness. relates to research using lists of words. More complex materials in real life produced better results. Suggests that context doesn't affect memory as much as Baddeley suggested.
Recall was short term: Weakness. unrealistic as ppts recalled the words almost immediately. Does not relate to scenarios like exams where the gap between learning and recall is longer. Therefore research only tells us about short term recall.
Similar context: Weakness. Context only acts as a cue if context of learning and recall are very similar. This rarely happenes in real-world situations. Therefore, context only improves memory recall in limited situations.
A study on False Memories
Aim: Loftus and Pickrell aimed to see if false memories could be created in a ppts.
Method: Ppts were given 4 stories about childhood events. Three true, one false (getting lost in a mall was the false). Story was created with help from a relative so it sounded realistic. Ppts read each story and wrote what they remembered.
Results: 68% true stories were remembered. 6 out of 24 (25%) of ppts recalled false story fully or partially. The rest had no memory of it.
Conclusion: Shows that imagining an event can implant a false memory in a person, reducing accuracy of memory
Evaluation for False memories
Artificial task: Weakness. False memory event is not as traumatic as what can be found in therapy. Harmless events might be implanted easily but traumatic events may not. Therefore, conclusions drawn about false memories may be limited.
Ethical issues: Weakness. Research raises ethical issues. Even though ppts were debriefed, they may be left with implanted false memories which lingered after study finished. Therefore, study may have caused psychological harm.
Real-world application: Strength. Research has implications for eyewitness testimony (EWT). Results suggest that police questioning could accidentally implant false memories. Therefore, research has been beneficial in explaining why EWT might be unreliable.