Memory notespack PDF

Preview

Summary

Download Memory notespack PDF

Description

AS Psychology – Unit 1: Memory 2016-2017

AS PSYCHOLOGY UNIT 1 SECTION B – Memory NOTES PACK 2016 - 17

1

AS Psychology – Unit 1: Memory 2016-2017

Extract from the specification: The multi-store model of memory: sensory register, short-term memory and long-term memory. Features of each store: coding, capacity and duration. Types of long-term memory: episodic, semantic, procedural. The working memory model: central executive, phonological loop, visuospatial sketchpad and episodic buffer. Features of the model: coding and capacity. Explanations for forgetting: proactive and retroactive interference and retrieval failure due to absence of cues. Factors affecting the accuracy of EWT: misleading information including leading questions and post-event discussion; anxiety. Improving the accuracy of EWT, including the use of the cognitive interview.

2

AS Psychology – Unit 1: Memory 2016-2017

SECTION 1: The multi-store model of memory: sensory register, short-term memory and long-term memory. Features of each store: coding, capacity and duration. The multi-store model of memory was proposed by Atkinson and Shiffrin (1968) and it is a structural model this means it focuses on the storage components of the memory system. This representation of memory sees memory as a transfer of information in a linear way through three separate and unitary stores. These 3 stores are: sensory register, short-term memory and long term memory. Rehearsal Sensory information

Sensory register

Attention

Short-term Memory

Rehearsal

Long-term Memory

Information received through the senses (what is seen, heard, tasted, touched and smelt) enters the sensory register. This information is held for up to 250 milliseconds (0.25 of a second) and will then decay quickly if it is not attended to. If the information held in the sensory store is attended to it will be transferred to the shortterm memory store. Information can remain in short-term memory if it is rehearsed but it cannot stay there for long. Information can be transferred to the long term store if it is rehearsed enough. Information in the long-term store can be retrieved when needed and can potentially remain there forever. The key feature of the multi-store model is that the short-term and the long-term stores are different. Atkinson & Shiffrin argued that each stored differed in: 1) Capacity -how much information can be held 2) Duration -how long the information can be stored for 3) Coding -how the information is processed into something that can be stored e.g. acoustically by sound or semantically by meaning 1) Capacity Sensory register Sperling (1960) Ppts were presented with a 3x4 letter grid for 1/20 th second. When a high, medium or low pitched tone was produced to indicate which row was to be recalled ppts scored ¾. Since ppt did not know which row they had to recall the information had to be available somewhere. This has suggested that the capacity of the sensory register is unlimited.

3

AS Psychology – Unit 1: Memory 2016-2017

Short-term memory Short-term memory has a limited capacity; we can only hold a small amount of information before it is forgotten. To investigate how much information can be held in STM, Jacobs (1887) devised the “serial digit span technique”. He presented participants with a sequence of numbers and using the serial recall procedure, asked the participants to repeat back the letters or digits to him in the same order in which they were presented. Jacobs found that the average STM span (number of items accurately recalled) was between 5 and 9 items. Capacity of STM can be increased by chunking items together to reduce the number of separate items overall. Miller (1956) conducted a review of studies that had investigated the capacity of short term memory which supported Jacob’s study, concluding that the capacity of STM was “7 plus or minus 2” chunks of information. Miller called this the magic number 7. Long-term memory In comparison with STM, research suggests that the capacity of LTM is unlimited. It is possible to lose data from your long term memory, through processes such as decay and interference, but forgetting does not occur because of capacity limitations. 2) Duration Sensory register Research has found the duration of the sensory register 250 milliseconds. Short-term memory The first attempt to measure the duration of STM was using an experimental technique called the Brown-Peterson technique. Participants were briefly shown consonant trigrams (e.g. BVM) and were given an interference task of counting backwards in 3’s to prevent rehearsal. After intervals of 3,6,9,12,15,18 seconds they were asked to recall the trigram. The interference task didn’t affect recall after 3 seconds but as time increased between presentation of the trigram and recall, performance declined. After 18 seconds, the memory trace for the trigram had decayed. Peterson & Peterson concluded that the duration of STM is approximately 1830 seconds. Duration can be extended by verbal rehearsal. Long-term memory Bahrick et al (1975) showed 400 participants aged 17-74 years a set of photos and a list of names, some of which were old school friends, and were asked to identify their old school friends in the photos. Those that had left high school 48 years previously recalled 80% of names and 70% of faces suggesting that memory for names & faces is long lasting. 3) Coding Sensory register Research shows that coding in the sensory register is modality specific i.e. there are separate sensory stores for different sensory inputs. Echoic for sounds, Haptic for touch, Iconic for sight, Olfactory for smells and Gustatory for tastes.

4

AS Psychology – Unit 1: Memory 2016-2017

Baddeley (1966) found that when participants were given a short term memory task there was acoustic confusion with words that sound alike. When given a long term memory task there was semantic confusion with words with a similar meaning. This difference shows that:  Coding in STM is mainly acoustic/sound based and encoding in LTM is mainly semantic. Summary of the differences between LTM and STM Capacity Duration Sensory register STM LTM

Coding

Unlimited

250 milliseconds

Modality specific

7+/- 2 Items i.e. between 5 and 9 Potentially unlimited

18-30 seconds

Mainly Acoustic

At least 48 Years

Mainly Semantic

Strengths and weaknesses of the multi-store model Strengths Evidence that the stores are separate 1) Brain scans, such as fMRI scans, have shown that different areas of the brain are active when doing memory tasks. For example, the prefrontal cortex is active when participants are doing a short term memory task whereas the hippocampus is active when long term memory is being used. This shows that STM and LTM are different stores. 2) Milner (1956) studied the case of H.M. whose hippocampus was removed to try and cure his epilepsy. This resulted in H.M being unable to form new long term memories although his STM – as measured by serial digit span – was unaffected. As there was a difference in the way the two memory stores were affected this shows that STM and LTM must be different stores. Weaknesses 3) Rehearsal is not the only process There is considerable evidence that simple rehearsal is one of the least effective ways of remembering. Craik & Lockhart (1972) suggested that long term memories are created by the processing that you do rather than through rehearsal. The more deeply you process something, the more likely you are to remember it. There is also evidence that some memories pass straight into long term memory without the need for rehearsal. These are called ‘flashbulb memories’. 4) STM and LTM are not unitary stores The model is regarded as an oversimplification of the structures involved in memory. It suggests that both LTM and STM are unitary stores, but research suggests this is not the case. Clive Wearing lost his LTM episodic memory (memory for events) and semantic

5

AS Psychology – Unit 1: Memory 2016-2017

memory (memory for facts) but not procedural memory (how to play the piano). This suggests that there may be more than one type of LTM.

SECTION 2: Types of long-term memory: episodic, semantic, procedural. Amnesiacs such as Clive Wearing have demonstrated that there are different types of LTM: 1) Episodic LTM: This is memory for events and information is stored with reference to a specific time and place. E.g. what you did during the summer holidays last year. Information stored within episodic memory is available for conscious inspection. 2) Semantic: This is memory for facts, general knowledge and the rules of language. This includes knowledge of what is meant by an orange or the name of your psychology teacher! Information stored within semantic memory is also available for conscious inspection. 3) Procedural: This is memory for motor skills and actions for example driving a car. It is referred to as an action or skills-based memory. Information stored within procedural memory is not available for conscious inspection.

Evidence for the different types of LTM 1)

Brain scans: There is evidence from brain scan studies to show that different types of LTM are stored in different parts of the brain. Episodic memories are stored within the right prefrontal cortex and semantic memories are stored in the left prefrontal cortex, whereas procedural memory involves both the cerebellum and basal ganglia

2)

Case studies: Clive Wearing lost all of his episodic and most of his semantic memory but not procedural memory as he could still play the piano providing evidence for the different types of LTM.

6

AS Psychology – Unit 1: Memory 2016-2017

SECTION 3: The working memory model: central executive, phonological loop, visuo-spatial sketchpad and episodic buffer. Features of the model: coding and capacity. The working memory model was proposed by Baddeley & Hitch (1974). The working memory model is concerned with SHORT TERM MEMORY only and working memory is seen as an active processor. Baddeley and Hitch (1974) used the term ‘working memory’ to refer to the type of memory you are use when working on a complex task which requires you to store information as you go along. Baddeley & Hitch proposed that STM was not a unitary (i.e. single) store. Instead it is a flexible and complex system that consists of a control mechanism (the central executive) assisted by three ‘slave’ systems (phonological loop, visuo-spatial sketchpad and the episodic buffer) that allowed for two tasks to be done at once. The working memory model:

Central Executive Inner scribe

Articulatory process Phonological Loop

Episodic buffer

Visuo-spatial sketchpad Visual cache

Phonological store

Long term memory

7

AS Psychology – Unit 1: Memory 2016-2017

Components of the model Central Executive This is the supervisory component which has overall control over the other three ‘slave’ systems. It plays the most important and complex role in working memory as it controls which information is and is not attended to. It also plays a major role in planning and combining information from the three ‘slave’ systems. The central executive has limited capacity and can only attend to a limited number of things at one time. The slave systems work independently of one another other. Phonological loop This is one of the ‘slave’ systems. Its function is to store a limited number of speech based sounds for a brief time. It is made up of a phonological store, known as the ‘inner ear’ which stores acoustically coded items and an articulatory control process, known as the ‘inner voice’ which allows words to be kept in memory by sub-vocal repetition. Visuo-spatial sketchpad This is the second ‘slave’ system and is sometimes called the ‘inner eye’. Its function is to hold a limited amount of information coded in a visual form for a short period of time. This system helps individuals to navigate and interact with their physical environment. The visuospatial sketchpad includes the visual cache, a passive temporary visual store which is linked to an active ‘inner scribe’ that acts as a rehearsal mechanism. Episodic buffer This is the third ‘slave’ system. It was added to the model in 2000. It is a temporary store responsible for integrating the visual, spatial and verbal information from the other stores and has a limited capacity of about 4 chunks.

8

AS Psychology – Unit 1: Memory 2016-2017

Evaluation of the working memory model Strengths 1) Dual Task Studies – provide support for the model- Evidence to support the model comes from dual task studies. Baddeley et al (1973) gave participants a simple tracking task (following a spot of light with a pointer as it moved round a circular path) while carrying out either a simultaneous visual imagery task or a verbal task. Participants had difficulty performing the two visual tasks. This is because the two tasks were competing for the same limited resources of the visuo-spatial sketchpad. However, participants could successfully carry out the tracking task while at the same time as performing a verbal task. This is because they were making use of the separate resources of the visuo-spatial sketchpad and the phonological loop. This supports the idea that there are separate components in the working memory. 2) Evidence from case studies - Patient K.F. suffered brain damage following a motorcycle accident. He had poor STM ability for verbal information but could process visual information. This suggests that just his phonological loop had been damaged and so provides evidence for the different stores. However, evidence is from a unique case that may not generalise to the whole population. 3) Evidence from brain imaging research- Brain imaging research shows different areas of the brain are active when performing different types of task. E.g. Frontal lobes - Attentional Task (central executive), left temporal lobe - Spatial Task (VSS) and left parietal lobe - Verbal task (PL). This supports the assumption that there are different subsystems for different functions in STM. 4) Practical applications-There is a high correlation between working memory capacity and performance on various tasks, it has been suggested that working memory capacity might be used as a measure of suitability for certain jobs. E.g. it has been used as a recruitment tool for the US air force. This shows that the model has real life applications. 5) Furthermore, the model has allowed us to understand and explain processing deficits like reading difficulties and therefore offers possible routes to strategies to help people with conditions like dyslexia. Weaknesses 1) Not a complete model- The model doesn’t account for musical memory because participants can listen to instrumental music without impairing performance on other acoustic tasks.

9

AS Psychology – Unit 1: Memory 2016-2017

2) Lack of clarity over the central executive-The central executive is the most important part of the model but it is the least understood. Its function is vague and difficult to test. This means the WMM has not been fully explained.

SECTION 4: Explanations for forgetting: proactive and retroactive interference and retrieval failure due to absence of cues. a) Interference This is where two lots of information become confused in memory resulting in forgetting one or both pieces of information. There are two types of interference: 1) Proactive 2) Retroactive Proactive interference This is when old learning prevents the recall of new information. Older memories disrupt the recall of newer memories. Pro meaning working forwards so interference is from old new. An example would be if you keep typing your old password instead of your new password because the memory of the old password is interfering with the memory of the new password. Retroactive interference This is where new learning prevents recall of old information. Newer memories disrupt the recall of older memories. Retro meaning working backwards so interference is from new old. An example would be if the memory of a new car registration interferes with the memory for a previous one. Interference is more likely when the two lots of information are similar. Interference is less likely to occur when there is a gap between instances of learning.

Evaluation Strengths 1) Evidence to support the explanation- McGeoch & McDonald (1931) gave ppts a list of 10 words to remember. They then learnt a new list that was either made up of: synonyms of the originals, antonyms of the originals, unrelated words, nonsense syllables or 3 digit numbers. There was also a 6th control group who learnt no new list. Ppts then asked to recall the original 10 words. They found that the mean number of words recalled was lowest in the group that were given the synonyms and highest in those that were given the digits. This shows that interference is strongest when the memories are similar. As laboratory studies are highly controlled this means that researchers can be confident the results are due to interference, therefore it is a valid explanation of forgetting. Weaknesses 2) Artificial nature of laboratory studies-Stimuli used in most experiments involves word lists and these do not reflect all of the things learnt in everyday life. This means that the

10

AS Psychology – Unit 1: Memory 2016-2017

interference explanation may be limited to explaining forgetting in the lab and not account for forgetting in real life. 3) Limited explanation -Interference really only explains forgetting when the two sets of information are similar. This means that the explanation is limited in explaining forgetting in the majority of real-life settings.

b) Retrieval failure This is when the information is available but cannot be accessed because of the absence of appropriate cues. A cue is a trigger of information that allows us to access a memory therefore a lack of cues will lead to forgetting. Types of cues 1) Context- Forgetting can occur when external environment is different at recall 2) State- Forgetting can occur when internal environment is dissimilar at recall (e.g. mood or level of intoxication) 3) Category- Forgetting is more likely to occur when material is not organised as organisation can create cues. Evaluation

Strengths 1) Evidence to support the explanation- Godden & Baddeley (1975) tested forgetting in deep sea divers. The divers were given a list of words to recall. There were four conditions: learn on land- recall on land, learn on land- recall underwater, learn underwater-recall underwater and learn underwater- recall on land. They found that recall was 40% lower in the non-matching conditions because the external cues available at learning were not available at recall. This study shows that contextual cues aid retrieval. Overton (1972) got ppts to learn material when either drunk or sober. He found that recall was worse when the internal state was different at recall. These state-dependent effects have also been demonstrated with marijuana, chewing gum and anti-histamine drugs. Both of these studies show that, in the absence of either contextual or state cues, retrieval failure can occur. Therefore it is a valid explanation of forgetting 2) This explanation of forgetting has been used to improve eyewitness testimony accounts. Reinstating the context is one of the four key principles of the cognitive interview. This means that the explanation has practical applications. Weaknesses 3) However, environment has to be very different to result in forgetting. Testing in a different room is unlikely to lead too much forgetting. This means that the explanation cannot always be applied to real life instances of forgetting.

11

AS Psy...