memory

Question 1

Outline the meaning of short term memory (STM).

Answer 1

STM is the capacity of the brain to hold a small amount of information for a short period of time. STM is the limited-capacity memory store (5 - 9 items on average). The duration of STM is about 18 - 30 seconds. Encoding of information is primarily acoustic.

Question 2

Outline the meaning of long term memory (LTM).

Answer 2

The permanent memory store. The capacity of long term memory could be unlimited. Duration can be anything from a few minutes to a lifetime. Encoding of information is primarily semantic (meaning).

Question 3

Describe the meaning of capacity.

Answer 3

The amount of information that can be stored in memory at any one time. Miller (1956) found STM has a capacity of 7 +/-2 items. LTM capacity is potentially unlimited.

Question 4

Describe the meaning of duration.

Answer 4

The length of time information can be held in memory. Peterson and Peterson (1959) found STM has a duration for roughly 30 seconds. Bahrick (1975) found LTM has a potentially unlimited duration.

Question 5

Describe the meaning of coding.

Answer 5

The format in which information is stored in various memory stores. STM is normally coded acoustically and LTM is normally coded semantically.

Question 6

Outline Jacobs’ (1887) research on capacity.

Answer 6

Jacobs (1887) measured digit span.
Participants were given a sequence of digits and then asked to recall them out loud in the correct order.



The sequence was increased by one each time until the participant could no longer recall the sequence. 
The mean span was 9.3 for numbers and 7.3 for letters.

Question 7

Evaluate Jacobs’ (1887) research on capacity.

Answer 7

One strength of Jacobs’ study is that it has been replicated. 
An old study is very old and is likely to have been poorly controlled.



Participants may have been distracted and performed worse. 
This may reduce the validity of the research due to poorly controlled confounding variables, e.g. the longer the digit sequence the more time there is to get distracted. 
The results of this study have been supported by further research supporting its validity.

Question 8

Evaluate Miller’s (1956) research on capacity.

Answer 8

Miller (1957) suggested that the number of items that could be held in short term memory was 7 (plus or minus 2). Miller based his ideas on the prevalence of seven in human evolution (7 days of the week, seven deadly sins etc).
Miller also noted that people can recall 5 words as well as 5 letters. This is because people can chunk information into one item.



Miller may have overestimated the capacity of STM. 
Cowan (2001) reviewed other research and concluded that the capacity of STM was only 4 chunks. This suggests Miller’s lower estimate of 5 is more appropriate.

Question 9

Evaluate research on the duration of STM.

Answer 9

Meaningless stimuli. The material used was artificial - nonsense trigrams do not represent real life.


Lack of external validity.

Forgetting can be explained by: spontaneous decay - if the information is not rehearsed the memory trace simply disappears, or displacement - new information pushes old information out due to the limited capacity of STM.

Question 10

Evaluate research on the duration of LTM.

Answer 10

Bahrick et al (1975) studied 392 participants from age 14 - 74.
Participants were asked to recall ex-school friends via: a photo recognition test of 50 pictures; a free recall test where they recalled the names of all people from their graduate class.



Photo recognition was 90% accurate after 15 years and 70% accurate after 48 years and free recall was 60% accurate after 15 years and 30% accurate after 48 years.


Real life memories were studied which gives this study a high external validity. 


Studies with meaningless information such as Shepard (1967) have much lower recall rates.


It is hard to control confounding variables in this study, e.g. participants are likely to have looked at yearbook photos and rehearsed their memory over the years.

Question 11

Evaluate research on coding.

Answer 11

Baddeley (1966a, 1966b) gave different word lists to four different groups. The word lists were: acoustically similar, acoustically dissimilar, semantically similar, semantically dissimilar. Participants had to recall the words immediately and after a period of time.


Participants did worse immediately with acoustically similar words.

Participants did worse after 20 minutes with semantically similar words. 


The study suggests we encode STM acoustically and LTM semantically. 


This study has been criticised for using artificial stimuli. This suggests it lacks external validity and so the findings cannot be generalised, e.g. it is highly likely meaningful material is encoded semantically in STM.

Question 12

What are the key features of the multi-store model of memory (MSM)?

Answer 12

Atkinson and Shiffrin (1968, 1971) (who created it) suggest memory is made up of three stores linked together by processing.


Environmental stimuli&raquo_space;> sensory register (iconic, echoic, other sensory stores)&raquo_space;> attention&raquo_space;> STM&raquo_space;> either response or prolonged rehearsal (which can go back to STM by maintenance rehearsal)&raquo_space;> LTM (can go back to STM by retrieval)

Question 13

Outline the sensory register aspect of the MSM.

Answer 13

A stimulus from the environment passes into the sensory register along with lots of other sensory information (sights, sounds, smells). There are five stores in the SR. One for each sense: auditory (echoic memory), visual (iconic memory), touch (tactile memory), smell (olfactory memory), taste (gustatory memory).
Duration is very brief (less than one second). Capacity is high. Coding depends on the sense. Little information from the SR passes further into memory. You have to pay attention for the information to pass to STM.

Question 14

How is information transferred from STM to LTM?

Answer 14

Maintenance rehearsal (repeating the information to yourself) keeps the information in STM.
If the information is rehearsed for long enough it passes into LTM - prolonged rehearsal.

Question 15

How are memories recalled in the MSM?

Answer 15

Information has to be transferred back to STM by a process called retrieval.

Question 16

Give one strength and one limitation of the MSM. (KF study)

Answer 16

The MSM is supported by research showing STM and LTM are different. Baddely (1966) found that we tend to mix up words that sound similar when using our STMs but we tend to mix up words with similar meanings when using LTM. This clearly shows that coding in STM is acoustic and LTM is semantic. This supports the MSM’s view that these two memory stores are separate and independent.


A limitation is that evidence suggests there is more than one type of STM. Shallice and Warrington (1970) studied KF, a patient with amnesia. KF’s STM for digits was poor when read out loud to him. His recall was much better when he read the digits himself. The MSM suggests there is only one type of STM but the KF study suggests there must be one short term store to process visual information and another to process auditory information. The working memory model is a better explanation for this finding because it includes separate stores.

Question 17

Give two limitations to the MSM. (other than KF study)

Answer 17

Another limitation of the MSM is that it only explains one type of rehearsal. Craik and Watkins (1973) argued there are two types of rehearsal - maintenance and elaborative. Maintenance is the one described in the MSM. But elaborative rehearsal is needed for long-term storage (linking information to your existing knowledge). This is a very serious limitation of the MSM as it is another research finding that cannot be explained by the model.


Another limitation is that research studies supporting the MSM use artificial materials. Researchers often asked participants to recall digits, letters. e.g. Peterson and Peterson asked participants to record syllables. These have no meaning/usefulness. In everyday life we form memories related to useful things and meaning - people’s faces, facts, places, etc. This suggests that the MSM lacks external validity. Research findings with meaningless material may not reflect how memory works in real life.

Question 18

Outline the episodic memory of the LTM store.

Answer 18

Stores events (likened to a diary of daily happenings).
Episodic memories are complex.



Events are time-stamped (you remember when they happened). 
They involve several elements (people, places, behaviours all in one memory). 


You have to make a conscious effort to recall them.

Question 19

Outline the semantic memory of the LTM store.

Answer 19

Stores our knowledge of the world (the meaning of words, taste of an orange, make of a car).
The memories are not time stamped.



You do not normally remember when you gained the knowledge. 
The knowledge is less personal - more to do with knowledge that everyone can share.

Question 20

Outline the procedural memory of LTM.

Answer 20

Stores memories for actions and skills.

Memories of how we do things (riding a bike, playing a sport).



Recall occurs without awareness or effort.


It is hard to explain these actions or skills as they are recalled without conscious awareness.

Question 21

Give three strengths about research into the types of LTM.

Answer 21

A strength of episodic memory is that it is supported by case study evidence. Clinical studies of amnesia (HM and Clive Wearing) showed both had difficulty recalling events that had happened to them in the past. However, their semantic memories were relatively unaffected (e.g. HM would not recall stroking a dog 30 mins previously but he knew the concept of a dog). This supports the view that there are different memory stores in the LTM as one store can be damaged but the others remain unaffected.


A strength is that brains scan studies show that there are different LTM stores. Tulving et al. (1994) had participants perform various memory tasks while their brains were scanned with a PET scanner. Episodic and semantic memories were in the prefrontal cortex; semantic in the left and episodic in the right hand side. This shows a physical reality in the brain to different types of LTM which has been confirmed in many research studies, supporting its validity.



A strength is that identifying different LTM stores has real-life applications. Psychologists can target certain kinds of memory in order to improve people’s lives. Belleville et al. (2006) found that episodic memories can be improved in older people with mild cognitive impairments. Training to improvements compared to the control group. This highlights the benefit of distinguishing between different types of LTM - it allows specific treatments to be developed.

Question 22

Give two limitations about research into the types of LTM.

Answer 22

A limitation of Tulving’s approach is that there may be only two types of LTM. Cohen and Squire (1980) argued that episodic and semantic memories are stored together in one LTM store called declarative memory (memories that can be consciously recalled). Cohen and Squire agree that procedural memory is a distinctly different kind of memory to semantic/episodic, and called it non-declarative. It is important to get the distinction between semantic and episodic memories right because the way we define them influences how memory studies are conducted.


A limitation is that there are problems with clinical evidence. Evidence is often based on clinical cases (e.g. HM and Clive Wearing) about what happens when memory is damaged. There is a serious lack of control of different variables in these studies. So it is difficult to generalise from these case studies to determine the exact nature of LTM.

Question 23

Outline the key features of the working memory model (Baddeley and Hitch 1674).

Answer 23

It is an explanation of how STM is organised and how it functions. It is concerned with the part of the mind that is active when you are thinking.


Central executive, episodic buffer, visuospatial sketch pad, phonological loop (articulacy control system and phonological store).

Question 24

Outline the key features of the central executive (CE).

Answer 24

Monitors incoming data. Allocates slave systems to tasks. Has a very limited storage capacity. Coding is flexible.

Question 25

Outline the key features of the phonological loop (PL)

Answer 25

Deals with auditory information. Preserves the order in which the information arrives. The phonological store stores the words you hear. The articulatory process allows maintenance rehearsal. Capacity is about 2 seconds worth of what you can say. Coding is acoustic.

Question 26

Outline the key features of the visuospatial sketchpad (VSS).

Answer 26

Stores visual and/or spatial information. Logie (1995) subdivided the VSS into: Visual cache - stores visual data. Inner scribe - records arrangement of objects in the visual field. Capacity is 3 or 4 objects. Coding is visual and spatial

Question 27

Outline the key features of the episodic buffer.

Answer 27

Added to the WMM theory in 2000. A temporary store of information. Integrates visual, spatial and verbal information from other stores. Maintains a sense of time sequencing. Links to the LTM.

Question 28

Evaluate the WMM.

Answer 28

The case of KF supports separate STM stores. Shallice and Warrington (1970) carried out a case study on KF who had brain damage. He had poor STM ability for verbal information but could process visual information normally. This suggests his phonological loop had been damaged but other areas of STM were intact. This suggests there are separate visual and acoustic stores. This evidence may be unreliable though as the evidence is from a brain damaged patient and may be unique.


Another strength is that dual task performance studies support the VSS. Baddeley et al. (1975) found patients had more difficulty doing two visual tasks than doing a visual and verbal task at the same time. The greater difficulty is because both visual tasks compete for the same limited resources. When doing a verbal and visual task there is no competition. Therefore dual task performance activity provides evidence for the existence of the visuo-spatial sketchpad. This is something that the MSM cannot explain.


A limitation over the WMM is the lack of clarity over the central executive. Cognitive psychologists suggest that the CE is unsatisfactory and doesn’t really explain anything. The CE should be more clearly specified than just being simply ‘attention’. Some psychologists believe it may consist of separate components. This means that the WMM hasn’t been fully explained.


A strength is that the word length effect supports the phonological loop. Baddeley et al. (1975) found people have more difficulty remembering a list of long words (long word length) than a list of short words (short word length). This is the word length effect. This is because there is limited space for rehearsal in the articulatory process. Word length effect disappears if a person is given a repetitive task that ties up the articulatory process - this demonstrates the process at work. This provides strong evidence to support the phonological loop.


Further support for the model comes from brain scanning studies. Braver et al. (1997) did brain scans of participants while they completed tasks involving the CE. Activity was seen in the prefrontal cortex. Activity in this area increased as the task became harder. This fits with the WMM: as demands on the CE increase, it has to work harder to fulfill its function. This provides evidence that the CE may have a physical reality in the brain.

Question 29

Describe research into the effects of similarity on interference.

Answer 29

McGeoch and McDonald (1931). Participants learned a list of words to 100% accuracy. They were then given a new list to learn. The new lists varied in how similar they were to the original.


Group 1: synonyms

Group 2: antonyms

Group 3: totally unrelated words

Group 4: nonsense syllables

Group 5: three-digit numbers

Group 6: no new list -

participants just rested 
Participants were then asked to recall the original list. Recall performance varied depending on which group they were in. The most similar material (synonyms) produced the worst recall. This suggests interference is strongest when memories are similar. In group 1 it is likely that the words with the same meanings as the original list blocked access or that the new material became confused with the old.

Question 30

Give two strengths on the theory of interference

Answer 30

Evidence from lab studies consistently demonstrates interference. Many lab studies have been carried out into interference (e.g. McGeoch and McDonald). Most of these studies show that both types of interference are very likely causes of forgetting from LTM. Lab experiments control the effects of extraneous variables which increases the validity of the findings on interference.


Real-life studies support the interference explanation. Baddeley and Hitch (1977) asked rugby players to recall the names of teams they had played so far in that season, week by week. Accurate recall was not related to how long ago the match was
More important was the number of games played before recall. This suggests more games caused interference with the memories. This study suggests that interference could apply to some everyday situations.

Question 31

Give three limitations on the theory of interference.

Answer 31

The research is limited by its use of artificial materials. The stimulus material used is often word lists. This is very different from things we remember in everyday life. In everyday life we remember faces, events, what we like to eat etc. The use of artificial materials makes interference much more likely in the lab.


Time periods between learning and recall in lab experiments are short. The research reduces the whole experience of learning into a short time period which is not reflective of how we learn and remember most information in real life. This means that conclusions from the research should not be generalised outside of the lab experience. This means the role of interference may have been exaggerated.



Interference effects may be overcome using cues. Tulving and Psotka (1971) gave participants five lists of 24 words. Each list was organised into 6 categories (e.g metals, types of fruit). Categories were not explicit but obvious. Recall was about 70% for the first list but fell with each additional list. When given cues to aid recall (told the names of the categories) recall rose back up to about 70%. This suggests memories of the words were stored in LTM but interference prevented access. Interference disappeared with a cue. This suggests that the memories had not been replace by interference but had been forgotten due to retrieval failure (accessibility).

Question 32

Describe the Johnson and Scott (1976) study on anxiety.

Answer 32

The study suggests anxiety has a negative effect on recall. Participants heard an argument in next room. Low anxiety condition: Man walks through with pen and grease on hand. High anxiety condition: Breaking glass sound, and man walks through with paper knife covered in blood. Participants were asked to pick out the man from 50 photographs. Correct was 49% low anxiety and 33% high anxiety. Tunnel theory/weapon focus effect - attention drawn to weapon.

Question 33

Describe the Yuille and Cutshall (1986) study on anxiety.

Answer 33

The study suggests anxiety has a positive effect on recall. There was a real-life crime - a thief was shot dead. 13 participants were interviewed 4-5 months after the incident. Accounts were compared to police interviews. Witnesses also rated their stress level at the time. Very accurate recall with minor inaccuracies (colours of items, age etc.) Highest reported stress were most accurate (88% compared to 75%).

Question 34

Explain the contradictory findings of anxiety on eyewitness testimony (EWT).

Answer 34

Inverted U theory - Yerkes and Dodson. Relationship between performance and stress is curvilinear. Deffenbacher (1983) reviewed 21 studies - lower levels of anxiety did produce lower levels of recall. Increases to an optimum level of accuracy and then declines.

Question 35

Explain a limitation of the Johnson and Scott study on anxiety and eyewitness testimony (EWT).

Answer 35

Participants may focus on weapon due to surprise instead of scared. Pickel (1998) - scissors, handgun, wallet and raw chicken held in a hairdressing salon. EWT higher for unusualness (chicken or handgun). Suggests weapon focus is due to unusualness instead of anxiety.

Question 36

Explain the limitations of studies into real-life witnesses and anxiety.

Answer 36

Interviews take place sometime after the event. Extraneous variables cannot be controlled e.g. PED. They may discuss the event or view accounts on the media. The extraneous variables may be responsible for the (in)accuracy of recall not anxiety.

Question 37

Explain the ethical issues concerned with research into eyewitness testimony (EWT) and anxiety.

Answer 37

Creating anxiety may subject people to psychological harm. Real-life studies may be more beneficial as there is no need to create an event. Ethical issues don’t challenge the findings of studies but raise questions about conducting such research.

Question 38

Explain the limitations of the inverted-U explanation.

Answer 38

Anxiety is difficult to measure - there are many elements: cognitive, behavioural, emotional, physical. Inverted-U assumes only physiological is linked to poor performance. The explanation fails to account for other factors e.g. the emotional experience of the witnesses on memory accuracy.

Question 39

Describe the impact of demand characteristics on lab studies of anxiety.

Answer 39

Participants know they are watching a filmed crime for a reason. They may work out that they will be asked questions and give responses to be helpful. The research is not measuring the accuracy of EWT. Reduces the validity of the research on anxiety and EWT.

Question 40

What does Eye Witness Testimony mean?

Answer 40

The ability of people to remember the details of events which they themselves observed.

Question 41

What is meant by retrieval failure?

Answer 41

Forgetting occurs due to a lack of sufficient cues. Cues are stored at the same time as the memory.

Question 42

Outline the Encoding Specificity Principle.

Answer 42

Introduced by Tulving. Cues help us to retrieve data. Cues that were present at encoding have to be there at retrieval. If a cue is absent then there will be some forgetting. Cues can be both meaningful and not.

Question 43

Outline one research study that investigated context-dependent forgetting.

Answer 43

Godden & Baddeley. On land and underwater. 4 conditions. Learned on land = best recall on land & vice versa.

Question 44

Baddeley (1997) argues that context effects are actually not strong, especially in real life. Explain this, and what it means for the theory.

Answer 44

Studies use contexts that are very different. In real life contexts are never going to be that different (change of rooms maybe). Studies don’t tell us about how memory works in the real world.

Question 45

Outline one research study that investigated state-dependent forgetting.

Answer 45

Carter & Cassaday. Antihistamines & not. 4 conditions. Learned with antihistamines = best recall with antihistamines and vice versa

Question 46

Why is a range of supporting evidence a strength of the retrieval failure theory?

Answer 46

Shows that the theory is valid and provides credibility.

Question 47

Explain the problems with the Encoding Specificity Principle.

Answer 47

Theoretical. Can’t provide proof - untestable concepts. Built on assumptions - if recall is good, we assume cue is present. Not falsifiable = unscientific.

Question 48

A criticism of the theory of retrieval failure is the effect may be related to the kind of memory being tested. Explain this.

Answer 48

Baddeley (1980) repeated the underwater study. Used a recognition test instead of a recall test - ppts had to say if they recognised a word read to them from the list. There was no context-dependent effect. Cues only affect memory when it is tested in a certain way.

Question 49

What is meant by the term misleading information?

Answer 49

Incorrect information given to the witness, usually after the event. It can take many forms, such an leading questions or post-event discussion.

Question 50

What is meant by the term leading question?

Answer 50

A questions that suggests, due to the way it is phrased, a specific answer. E.g. Was the man holding the knife in his left hand?

Question 51

Briefly outline one study that has investigated leading questions as a factor affecting the accuracy of eyewitness testimony.

Answer 51

Loftus and Palmer - showed ppts a video of a car crash, then asked participants about the speed of the cars, using increasingly aggressive verbs to describe the crash (bumped, hit, smashed etc). Found that the more aggressive the verb, the faster the speed was estimated. Leading questions have an impact on recall.

Question 52

Outline 2 explanations for leading questions as a factor affecting the accuracy of eyewitness testimony.

Answer 52

The response bias explanation. The wording has no effect on the memory, but influences how the witness decides to answer.
The substitution bias explanation. The wording actually leads to the memory being altered.

Question 53

Briefly outline one study that has investigated post-event discussion as a factor affecting the accuracy of eyewitness testimony.

Answer 53

Gabbert et al. gave participant pairs a video of a crime to watch. Both partners saw the crime from different angles (they each saw aspects the other did not). Afterwards ppts were allowed to discuss the clip and the research found that 71% of ppts recalled events that they had not seen. Witnesses go along with each other → memory conformity.

Question 54

Explain why it might be better to carry out research into eyewitness testimony in the real world, rather than in a laboratory.

Answer 54

Lab studies cannot replicate the stress people would feel if being a witness in the real world. Such emotions can have an effect on memory and cannot be replicated effectively in a lab setting. Conducting studies in a lab tells us nothing about eyewitness testimony in real life because the setting and materials are artificial.

Question 55

Outline some research into individual differences in EWT.

Answer 55

Factors such as age can affect the recall eyewitnesses. Anastasi and Rhodes found that younger age groups were more accurate in their recall than older age groups. Additionally the study found that people are always better at recognising people their own age. Studies often use younger people as the target and so some age groups may appear less accurate, when in fact they are not.

Question 56

A strength of research into EWT is that is has useful real world applications - explain this.

Answer 56

Consequences of inaccurate EWT in the real world can be devastating. Research on this has lead to police officers changing their questioning technique in order to avoid the distorting effect of misleading information. Research into this area can help to improve the legal system and increase the chances of eye-witnesses giving sound evidence.

Question 57

Give two reasons why lab research into EWT may be inaccurate.

Answer 57

Lack of consequences. PPTs usually know they are taking part in a study. They know that, no matter how serious or horrific the incident, the answers they give will not have any significant effects. This is not the case in real life → leading questions may have less of an effect when the consequences are more serious.
Demand Characteristics. Zaragosa and McGloskey (1989) argue that answers given in lab studies of EWT are largely down to demand characteristics. PPTs do not want to let the researcher down (or want to influence the results) and so lie (if they do not know the answer). There is a danger that participants will not behave how we want them to, i.e. naturally. When this happens, it decreases the validity of research studies because they are no longer measuring the accuracy of eyewitness testimony.

Question 58

What are the 4 stages of the cognitive interview?

Answer 58

Report Everything. Include every single detail of the event - seemingly trivial details could be important and could trigger other memories.


Reinstate context. Return to the crime scene in their mind (environment, senses etc), and emotions → context-dependent forgetting.



Reverse the Order. Recalled in a different order to the original → prevents the reporting of expectations and dishonesty.


Change of perspective. Recall the event from the perspective of other people (e.g. witnesses or perpetrator) → disrupts expectations & Schemata.

Question 59

What is meant by the enhanced cognitive interview?

Answer 59

Fisher et al. (1987). Additional elements to focus on the social dynamics of the interaction. E.g. knowing when to establish eye-contact and when to relinquish it. Reducing anxiety, minimising distractions, speaking slowly, using open ended questions.

Question 60

Why are many police forces are reluctant to use the CI?

Answer 60

The CI is time-consuming when compared to the standard interview. More time is needed to establish rapport and allow them to relax. CI also requires special training → forces may not have been able to provide more than a couple of hours training. It is unlikely the proper version of the CI is actually used → explain why police have been unimpressed.

Question 61

Outline research that supports the effectiveness of the Enhanced Cognitive Interview.

Answer 61

Köhnken et al. (1999) combined data from 50 studies - meta-analysis. The ECI consistently provided more correct information than the standard interview. There are real practical benefits to using the ECI → gives the police a better chance of catching criminals.

Question 62

Why is it difficult to draw conclusions regarding the effectiveness of the cognitive interview?

Answer 62

Variations are used in every study. Different techniques & the ECI. If a research study evaluates the effectiveness of one version of the CI, then the findings may not apply when it is used differently by a different police force. This makes it very difficult to compare the ways the CI is used. It also makes it easier for police officers to reject it because they could argue, ‘it’ll never work here’.