Home            |        AS             |        A2          |         Links       |

Multistore Model

Working Memory Model

Eye Witness Testimony

Leading Questions

Improving Memory

Memory is a complex and varied phenomenon.  Ideas about what constitutes memory and how it works can be traced back to ancient times.  Plato compared memory to an aviary, and in some respects his ideas have remained little changed into the modern era. 

Plato likened human memory to an aviary with memories (birds) flying around inside.  A new bird can be captured and added to the aviary (placing a new memory into storage), and at a later date the bird can be captured in a net and removed (retrieval of a memory). Inability to capture a bird or its escape from the cage are useful analogies for the two basic processes of forgetting.

Some modern theories of memory still use this principle of storage and retrieval, however it is becoming more popular now to see memory as a process rather than simply a storage system.  Research in recent years has shown that far from being a perfect recording of an event our memories do change over time and can be influenced by others and by later events. 

The notes that follow are meant to provide a thorough overview of the topic as it is described by the AQA Specification.  They should be regarded as a bare minimum and consequently should be supplemented by class notes and independent notes following your own extensive background reading! 

An evolutionary perspective

We take memory for granted and cannot imagine a life that had no past experience to give the present some kind of context.  Animal memory is quite different to our own despite human memory almost certainly evolving from the ability of lower species to recall certain events. 

For animals memory is about food (finding it or finding where they’ve cached it), mates (where to find them) and predators (where to avoid them).  Some species have evolved what we would consider to be amazing memories. 

Squirrels and many bird species like the black-capped chickadee and Clark’s nutcracker, can recall the sites of dozens, in some cases thousands of sites where food has been cached for the winter.  Pigeons can remember routes back to their nests from hundreds of different locations using landmarks and possibly smells. 

However, other species also forget.  For example the chickadee will forget where it has hidden food usually within 28 days.  Forgetting therefore seems to be of evolutionary advantage.  Cached food will presumably be either rotten or discovered by somebody else if not eaten within that time.  Remembering past this ‘sell by date’ would therefore be a pointless activity.  Perhaps human forgetting was once something to be blessed rather than cursed. 

The multistore model:

Background

The multistore memory (Atkinson and Dhiffrin 1968) suggests memory has two main components; STM and LTM.  In addition it also has a set of sensory stores where images, sounds, smells etc. appear to reverberate around still at the sensory locations momentarily.  The model will be discussed in more detail a little later, but to make more sense of the model we will first consider the two main stores, their feeders (the sensory stores) and the differing properties of STM and LTM.

Sensory Memory

Sensory memory acts as a filter with each sense having its own brief ‘storage system.’  Throughout the day and to some extent even when we are asleep, our senses are bombarded with information.  So as you’re sat reading this there will be other visual stimuli around you, there will also be noises, smells etc.  Few if any of these will be remembered.  When you walk into town or to school you will pass dozens of cars, but unless they are in some way unusual you will recall no detail about them.  The sensory memory appears to hold information for a fraction of a second.  If we decide that the information is not important it disappears and will not be recalled later.  Only if it is important (particularly if it is threatening), unusual or meaningful will we pay attention to it and transfer it to STM.  Sensory memory therefore plays a vital role in filtering out the vast majority of useless stuff that impinges on our senses and enables us to focus our attention on important detail.

Sperling (1960) presented participants with grids of 12 letters arranged in three rows.  Each grid was displayed by a tachistoscope, designed to present the letters for 50 milliseconds. 

So in a follow up Sperling played a tone straight after the letters had disappeared.  A high tone signalled that the top row should be recalled, a low tone the bottom and a mid tone the middle row.  Sperling found that even though the words had been removed before the tone sounded, there was still sufficient time for the participants to be able to ‘glance back’ through their visual store and recall an average of three of the letters from the appropriate row. He concluded that participants could therefore hold about 9 or 10 items in their visual sensory (iconic) store.

Some children have an eidetic memory allowing them to store information in the short term sensory store for much longer than the half second or so most of us can manage.  Haber & Haber (1964) gave such children a picture from Alice in Wonderland that they were allowed to study for 30 seconds before it was replaced by a blank sheet.  They were then asked questions about minor details in the picture.  Their eyes would scan corresponding areas of the blank sheet as they recalled, in the present tense, with considerable accuracy details of the picture that had long since disappeared from view. 

The human echoic store (sensory store for hearing) is particularly useful.  Without it conversation would be difficult since it holds words for a few seconds allowing us to recall what was said at the start of a sentence as well as at the end. 

Imagine yourself vegetating in front of “I’m a celebrity chef with a delinquent nanny get me an interview in the House with Alan Sugar.”  You can feel yourself slipping into a lowered state of consciousness as rigor mortis of the brain sets in!  Your mum asks you what’s on the other side and you look round, temporarily roused from slumber and say “What?”  As you do so you’re able to rewind the question in your mind and it occurs to you that you did hear what he said after all!  This would be your sensory store for sound in practice; the sounds were still reverberating in your ear! 

Short term memory (STM)

We will look at capacity, duration and encoding in terms of STM and later in terms of LTM.

Capacity

Capacity refers to the amount of information that can be held at any one time in memory.

Capacity of STM is limited.  Experiments that investigate capacity traditionally use the serial digit span method in which numbers/letters etc have to recalled in the correct order.  The most famous study was Miller’s (1956) ‘magic number seven plus or minus two.’ However, procedures for this study are notoriously difficult to find, so instead Jacobs’ (1887) study might be better to discuss.  The two are very similar.

Factors affecting measured capacity:

Reading the lists out loud appears to increase recall.  Baddely believed this was because the words had been stored briefly in echoic memory and strengthening the memory trace.

Pronunciation time: we can recall fewer words if they take longer to pronounce.  One study found that Arabic speakers could recall fewer numbers because the names of their numbers take longer to say! 

Duration

Refers to the amount of time that a memory can be stored.  In STM this is also limited.  Traditionally duration in STM is measured by the Brown-Peterson technique.  The technique was devised independently in 1959 by Brown and by Peterson and Peterson, hence the name.

Factors affecting duration of STM

Obviously rehearsal will help with duration of STM.  Try to remember the registration of that speeding car and you will repeat it to yourself over and over. 

Amount of information: Murdock 1961 used a version of the Brown-Peterson technique to show that number of chunks affects duration.  Participants were given either three letters that spelt a familiar word such as c, a, t or three unrelated three letter words such as sun, pat, lid.  The latter deteriorated at the same rate as predicted by B-P so recall after 18 seconds was minimal.  However, recall of the three letters was very stubborn to erase and after 18 seconds recall was still at over 90%.

Encoding

Encoding refers to the format or code in which a memory is stored as a memory trace.  Encoding can be by sound (acoustic) or by meaning (semantic) or by other means too. 

The key study here can be used for STM and for LTM since it investigated both.

Long term memory (LTM)

Evidence for two memory stores (STM and LTM)

This is a favourite on examination papers.  Clearly you could talk about research into the two main memory stores mentioned above.  In addition to this it would be essential to mention some, if not all, of the following:

Multistore model of memory

Discussed in the next section, this would be a good start to the essay since it suggests how the two main stores work in conjunction with one another.

Primacy and recency effect.

Murdock (1962) gave 103 psychology students lists of words to free recall (in any order) in 90 seconds.  Typically words at the start of the list and especially those at the end tended to be recalled most often.  This was explained by words at the start being rehearsed from STM into LTM creating a stronger trace and those at the end still being present in STM when recall begins.  Evidence for two separate stores. 

Primacy effect                                                                Recency effect

           (rehearsed into LTM)                                                       (Still present in STM)

Amnesiac case studies. 

Most people with memory problems have either impairment of their STM or LTM, not usually both.  This suggests that they are different systems. 

HM (or Henry M)

The classic case is that of H.M who at the age of 27 underwent surgery in an attempt to cure his epilepsy apparently triggered by a cycling accident when he was nine.  A surgeon, William Scoville removed both his temporal lobes including a structure known as the hippocampus (Latin for sea horse) and an area known to be crucial to memory. 

Following the procedure HM was unable to create new long term memories (anterograde amnesia) and lost some of his existing LTM retrograde amnesia).  However his STM remained intact with a normal capacity and duration, limited only by his inability to rehearse. 

HM is still alive today, now in his early eighties and being cared for in a residential home in Connecticut (Wikipedia) he is still being studied by cognitive psychologists!   HM’s pattern of memory loss is not unusual.  Clive Wearing suffered a similar form of amnesia following a herpes simplex (cold sore) infection that spread to areas of his temporal lobes. 

Interestingly in both cases and in most cases of amnesia affecting LTM it is mainly episodic memory that is lost, the ability to recall memories of events and certain factual information such as faces, dates etc.  So called semantic memory is largely unaffected so patients can still use language, walk, cycle etc. and still retain an understanding of ‘how things work.’ 

HM therefore could be taught new skills, which over time would improve with practice.  However, he would have no recollection of ever having performed them before!  

KF who suffered damage to his STM following a motorcycling accident still retained a near normal LTM.  However, yet again the situation wasn’t quite that simple since KF could still recall visual information using his STM but struggled with auditory and verbal information, making conversation difficult. 

We therefore have a situation were cases of amnesia can both support the idea of two memory stores whilst at the same time question the idea.  This is particularly good stuff to include in a discussion of the existence of two memory stores. 

Two memory stores

Amnesiacs tend to lose only one store (either STM or LTM) supporting the idea of two separate stores presumably located in different brain areas or structures. 

More than two stores

However, HM and Clive Wearing both provide us with evidence that LTM is more complex and seems to comprise at least two components (semantic and episodic LTM).  More on this when we look at types of LTM.  Similarly KF suggests that STM is also more complicated having separate stores for both auditory and visual information.  See later section on working memory.

Working memory model

This is explained in later sections and argues that STM may not be just one store but a collection of components each with a different task.  This would be evidence for there being more than two stores.

Brain areas

Modern scanning techniques have found that different areas of the brain operate when different stores are being used providing best evidence for different memory types.  The prefrontal cortex is active when STM (now more correctly referred to as working memory) is being used whereas the hippocampus in the temporal lobes is active for LTM.

Types of Long term memory

First a note of caution.  ‘Types of long term memory’ is not specifically mentioned in the specification, nor do some of the texts, e.g. Cardwell for AS cover the topic.  However, some texts, including ours, do and the wording in the specification is sufficiently woolly to allow a question on it.  To date no questions have been set on the topic, however, information contained in this section and covered in class will at the very least be useful in part c questions that deal with STM and LTM.

We saw in the videos on amnesia that many patients suffering memory loss still have vital aspects of their LTM intact.  It is very rare for amnesiacs to lose their memory for skills such as language (reading and writing) and for walking, swimming etc.  As we saw in the case of Clive Wearing his ability to play the piano and conduct choirs was still intact despite most other memories having been lost.  In the video his long suffering wife says that his episodic memory is severely impaired whilst his semantic memory is largely intact.  This is one way of distinguishing types of LTM, however, there are others:  What follows is a brief summary of these, with examples and similarities drawn between them.

Episodic and Semantic (Tulving 1972)

• Episodic memory contains the details of your life.  When Victoria Beckham gets someone to write her autobiography for her she would first sit down and tell them, presumably in words of not more than two syllables, all the interesting events that have happened to her.  For example the chive she had for dinner each day in August and the counselling she received on discovering she had a split end! 
• Semantic memory contains our memories of the World and how it works.  Continuing the theme, hubbie Dave would store here his vast knowledge of the English language, capital cities of the World (presumably so they can name their next son Ulan Bator), and most importantly his footballing skills, specifically how to bend it like… well Beckham! 

Research evidence: Tulving (1989) using radioactive gold, found different areas of the brain are active when the two memory types are being used.  Episodic engages the frontal lobes, semantic the posterior lobes.

Declarative and Procedural (Cohen and squire 1980)

• Declarative (knowing that).  For example knowing capital cities and other factual information and knowing about personal events in our life.  This is different to Tulving who believed that these two types of information were stored in different aspects of LTM.
• Procedural (knowing how).  This covers our knowledge or memory for skills such as walking, talking, driving, playing football etc.

Research evidence: Squire et al (1992) used PET scans to show that different areas of the brain were active during each memory type. 

Implicit and Explicit (Graf and Schacter 1985)

• Explicit: similar to declarative and being used for memories that we have to consciously recall, for example we need to think about personal memories and memories for trivia.
• Implicit: similar to procedural and being used for memories that we don’t have to consciously think about.  These are mostly skills such as walking and talking.  If we do consciously think about such activities e.g. driving, they can become more difficult.

Evaluation: Implicit/explicit is particularly useful in explaining amnesia in brain-damaged patients, typically these having damage to their explicit memory but retaining an intact implicit memory. (E.g. H.M. and Clive Wearing).

Models of Memory

Multi-store Model of Memory:  Atkinson & Shiffrin (1968)

This model builds on the idea of three memory stores and tries to explain how they work together.  The model sees memory as a flow of information through a system.  The model takes an information processing approach and as such it is usually represented in the form of a flow diagram.  Exam tip: in your exam it is advisable to describe the model in words.

Components

Sensory Memory stores the incoming information from the senses.  The model assumes that these are modality specific, that is there is a separate store for each of the five senses.  The store is very brief and the vast majority of information is lost here.  Only information that is relevant or important is attended to and passed on to STM.  Forgetting from the sensory store is by decay.
 

STM Atkinson & Shiffrin believed the store to be fragile and retains information for about 30 seconds.  Compare this to the 18 seconds of the Brown–Peterson technique.  Material that is rehearsed is passed on to LTM.  Forgetting from STM is by displacement or decay.

LTM can store this information for a lifetime.  Forgetting from LTM is by decay or interference.  (note: displacement is not an issue since capacity is limitless).

Processes

Attention: needed to transfer information from the senses to STM.  Most stimuli that reach the senses are ignored because they aren’t seen as important.  Only relevant or interesting information, or material that we choose to concentrate on is passed to the STM.  99% is lost at this stage.

Rehearsal: needed to transfer information from STM to LTM.  We can rehearse information out loud as a child would do learning times tables by rote, or we can rehearse sub-vocally, in our heads.  Either way it is seen as crucial and is one of the main criticisms of the theory, as we shall see.  Later models distinguished between maintenance rehearsal in which material is repeated in ‘rote’ fashion to maintain it in STM and help with transfer to LTM.  Elaborative rehearsal links the information with existing material or elaborates it in some other way, again as an aid to longer term storage. 

Evaluation

·         The model has simplistic appeal and has been influential in stimulating research.  Other models such as the ‘working memory model’ take the multistore model as starting point and then add to it.

·         Various studies that suggest the existence of two separate stores support the theory.  For example Murdoch (1962) found evidence for a primacy and recency effect.  As already mentioned primacy effect due to information heard first being rehearsed and passed to LTM and recency effect because recently heard or seen information is still present in the STM. 

·       On the face of it, amnesiac case studies such as Clive Wearing, H.M. and K.F. also provide evidence for a distinction between two different stores, since usually amnesiacs have one aspect of memory such as STM intact whilst other aspects show impairment.

·        There appears to be a distinction between stores in terms of capacity, duration and encoding.

However

·       The model is too simplistic:

·       Given the multitude of different memories we store it is unlikely that LTM is a unitary store.  Others have distinguished between semantic memory (for skills) and episodic memory (for facts and events) as already mentioned.

·       When considered more closely case studies of amnesiacs suggest that both STM and LTM are far more complex than the multi-store model suggests, e.g. Clive Wearing has an intact memory for skills but a severely impaired memory of facts.  KF has a severely impaired STM but his LTM is intact.  According to the multi-store model this could not happen since the memories in LTM must pass through STM first.

·       Flow of information is assumed to be one way, but it seems likely that our LTM is able to assist our STM suggesting a ‘reverse flow.’  Consider the chunking exercise we did: 106619381945.  In order to chunk this successfully you would need to use your vast knowledge of historic dates stored in your LTM, clear evidence of LTM aiding STM. 

·       Ruchkin et al (2003) took this idea a stage further.  They gave participants lists of a mixture of real words and made-up words to recall from STM.  The brain activity for real words was very different suggesting other brain areas (presumably areas of STM) were being involved in the memory process (this area would be able to distinguish real from made-up). 

The researchers concluded that in fact STM was probably just the bit of LTM being used at any one time!

·       The role of rehearsal is probably over stated.  We often remember facts without conscious rehearsal.  Tulving (1967) got participants were asked to read a list of words over and over again.  Later participants were asked to remember another list of words containing a mixture of ‘old’ (ones read earlier that day), and ‘new’ words.  Tulving found that participants were just as likely to recall the new words as the old ones suggesting that rehearsal has little effect in transferring memories to LTM. 

·       Finally the multi-store model provides a passive explanation of memory.  Research suggests that memory is an active process, for example STM being involved in our ability to focus attention and guide our thinking and LTM being used to help STM in this process.

The working memory model seeks to explain the operation of ‘STM’ in more detail.

Working Memory Model:  Baddeley & Hitch (1974)

The working memory model including its strengths and weaknesses

It seems that STM is far more complex than the multi-store model assumes.  Working model proposes an active, multi-component short term memory store with each sub-system having its own role to play in learning, problem solving and concentration.

The original model comprised three components

The central executive: is the control centre responsible for coordinating the other slave units.  It is able to process information from any of the senses and appears to have a minimal storage capacity.  We use the central executive when we are concentrating on a task and it is sometimes likened to ‘attention.’  If we are attempting to do two things at the same time, for example read and hold a conversation, it is the central executive that switches our attention between the two, deciding which other components of the working memory to use.  People attempting to drive whilst using a mobile phone are therefore dividing their attention and stretching their central executive. 

Slave systems:

Articulatory (phonological) loop: is sometimes called the inner voice.  It holds sounds for a few moments (one to two seconds), storing the sounds temporally, i.e. sounds we hear first are stored first.  This is important for example when we are replaying a sentence to check its meaning or when we are rehearsing a telephone number.  The clearest illustration of the loop in use is that situation we are all familiar with; you are sat reading and not switched on to events around you.  Someone asks a question and you realise that it is being directed at you.  You ask the person to repeat what they’ve just said with a polite ‘AYE?’  However, before the word is out you realise that you do know the question.  The words are stored in your loop and you area able to play them back as you would when rewinding and replaying a tape.  Baddeley et al (1975) found that the loop can hold about 2 seconds worth of sounds, so it can hold more short words than it can long ones.

Visuo-spatial scratch pad: or inner eye.  This also has a limited capacity and stores visual information in its component form, e.g. as shape, colour, size etc.  It also considers spatial arrangement of shapes etc.  Evidence suggests that we use the scratch pad (sometimes called the sketchpad) to manipulate images in our head.  For example if you counted the number of windows in your house you would visualise the layout by recalling the image to your sketchpad.

Episodic buffer was added by Baddeley in 2000.  The central executive has no storage of its own and the other two stores hold either visual or auditory data.  Baddeley realised that there needed to be a store that could hold and coordinate information from all three other stores as well as from LTM.

Research evidence

This usually takes the form of getting participants to use different components of the model and examining their performance.  If the same component is used to carry out two tasks simultaneously then because capacity is limited performance is impaired on both tasks.  However, if participants perform two tasks together that rely on different components each task can be performed normally. 

Baddeley (1986) got participants to complete two tasks simultaneously:

1.       To remember a list of numbers (a so called digit span task)

2.       To answer true or false to a number of problems such as

                        BA                    A follows B (true or false)

If STM is a unitary (single store) as proposed by the multi-store model, and has a capacity of around 7, then as task 1 reached 7 digits there would be no capacity left to carry out task 2.  In fact this was not the case.  Both tasks could be performed at the same time.  However as the number of digits in task 1 was increased the speed at which task 2 could be completed slowed, but not appreciably. 

Evidence for the articulatory loop

This store appears to hold the number of words you can say in two seconds so as a result we are able to rehearse and recall more short words than we can long words because it takes longer to rehearse ‘articulatory’ than it does ‘loop’ for example.  However if participants are given an articulaltory suppression task, e.g. saying ‘the, the, the…’ neither short words nor long words can be rehearsed and both tasks suffer. 

Evidence for visuo-spatial sketchpad

Again tasks were provided that involved doing two simultaneous visual tasks such as tracing a white light around a circle and commenting on the angles in letters.  Performance on both visual tasks suffers when done together because the capacity of the sketchpad is limited.  Baddeley himself reported an incident when he was listening to a game of American football whilst driving.  He tried to visualise what was happening on the pitch and found that his driving became erratic.  I tried something similar a few years ago: whilst driving in Kettering I tried to count the number of traffic lights I have to negotiate whilst driving out of Mansfield (my home town).  I found it very frustrating to find that I simply couldn’t do both tasks at the same time.  Luckily in my case the driving took precedence and the counting of traffic lights was the task that seemed to suffer!  (Not to be used as an example in written answers… stick to the professional research!)

Evidence for the central executive

Traditionally tasks that involve both processing and memory span have been used to test the central executive.  For example being read sentences and having to recall the last word in each sentence.  Imbo et al (2007) gave participants long multiplication tasks to do in their head.  Consider how you would multiply 237 by 41 for example.  You’d probably begin by multiplying 7 by 4 which involves one number (8) being stored and another (2) being ‘carried over.’  This carry over requires the articulatory loop whereas the calculation itself is requiring the central executive (and presumably LTM).  Having more complex sums involving larger numbers and more ‘carry overs’ made the task more difficult suggesting that the CE is involved in both holding the carry over and storing its value. 

Evaluation

·         Active process: It sees memory as an active process and not merely a passive store.  This is in keeping with more modern views of memory that don’t see it as a ‘thing’ but a function or process. 

·         Rehearsal: It only considers rehearsal to be important in the phonological loop.  It is widely considered that the multi-store model does place too great an emphasis on rehearsal in transferring information to STM.

·         PET scans (Positron Emission Tomography), show that different parts of the brain are active when different parts of the system are in use.  This provides further evidence for distinct components.  The central executive seems to reside in the frontal cortex and the scratch pad in the right side of the occipital lobe, known to be associated with vision.

·         Amnesiac case studies: A single component STM is unable to explain the case of KF, who, following a motorbike accident suffered impairment of his STM.  Shallice & Warrington (1974) showed that although his memory for verbal material was poor his memory for visual information was unaffected.  In terms of the working memory model this can be explained by damage to the articulatory loop but with the sketchpad remaining intact.

·         Baddeley (1986) found that patients with damage to their frontal lobe had problems concentrating suggesting damage to the central executive.

The fact that different brain areas appear responsible for separate functions and therefore separate components does support the concept of a multi-component system.

However although the model is popular there are still a few issues with it:

Very little is known about the central executive, the main component, the central executive.  For example we have no idea of its capacity.  Some see it almost as an umbrella store doing all the functions that can’t be explained by the slave units so in fact it not be a unitary component at all but rather a collection of independent but interacting entities.  Elsinger & Domasio (1985) studied a man who suffered trauma following the removal of a brain tumour.  Although his IQ was still high and he could cope well with interference during memory tasks he was quite unable to make decisions.  The fact that some functions associated with the CE were intact whereas others were impaired provides evidence for the CE being a collection of separate components. 

Baddeley (2001) added the episodic buffer making the model more complex.  This suggests again that the model is not complete and may need still further revision as more evidence is uncovered.

Overall the model has proved to be influential and has stimulated lots of research.  It is still being developed and expanded.

Levels of Processing: Craik and Lockhart

This is different to the other two theories as it does not consider different stores or physical components.  Basically it believes

1.       Depth of processing carried out on incoming information has a substantial effect on how well we remember it.

2.       Deeper levels of analysis produce longer lasting and stronger memory traces than shallow levels of analysis.

Shallow levels of processing include simply noticing the physical characteristics of the material to be memorised, e.g. the shape of the letters such as upper or lower case.  Learning by rote (or parrot fashion) is called maintenance rehearsal and is also seen as shallow.

Medium levels of processing include noticing the sound of the material to be learned, referred to as phonetic processing (e.g. does the word rhyme with…?).

Deep levels of processing are semantic since they consider the meaning of the material to be learned.

Research into LOP

1. Craik & Tulving (1975) presented participants with words via a tachistoscope.  After each word they were asked one of four questions: 

1.       Is the word in upper case? (shallow processing)

2.       Does the word rhyme with chair? (phonetic or medium processing)

3.       Is the word a type of food? (semantic or deep processing)

4.       Would the word fit into the sentence ‘He kicked the …… into the tree. (semantic or deep processing).

Findings: Participants remembered more of the words that had been semantically processed.

2. Hyde & Jenkins (1973) got participants to listen to lists of 24 words and carry out one of a number of different tasks, for example: 

1.       Estimate how often the word is used in the English language

2.       Spot the letters ‘e’ or ‘g’ in any of the words

3.       Decide whether the word is a noun, verb etc.

4.       Decide whether or not the word would fit into a particular sentence.

Half the participants were told in advance that they would be tested on the words afterwards, the other half were not. 

Findings:  Whether the participants had been told to expect a test or not made little difference to their recall.  This is what Craik & Lockhart would predict since they consider intention to learn to be unimportant in the learning process.  Also, the words that were semantically processed were recalled better.

Evaluation

Influential when it first appeared particularly since it concentrates on steps we take to memorise information.

But

·         It is difficult to asses how deeply a word has been processed, this makes it difficult to test the theory.  Some psychologists believe the arguments are circular.  Effort rather than depth may be important.  Tyler et al (1979) gave participants easy or difficult anagrams e.g. DOCTRO or OCDRTO.  Later participants remembered the difficult anagrams better even though the type of processing was the same.  What had altered was the effort put in.

·         Elaboration and distinctiveness may also be important, as we saw with the lovely Kylie.

Eye witness testimony (EWT)…

…and factors affecting the accuracy of EWT, including anxiety, age of witness. 

Introductory comments

This little bit is aimed at giving you some idea of how influential EWT can be in convicting alleged criminals. 

The Devlin Report (1976) investigated the accuracy and importance of EWT following some serious miscarriages of justice.  The report examined over 2000 identity parades in England and Wales in 1973 and followed them through to their outcomes in court. 

Of the 2000 parades 45% (900) resulted in a suspect being identified and out of these 900 82% were convicted of the crime.  In over 300 cases the EWT was the ONLY evidence provided and 74% of these were convicted!

Although juries love EWT (and so do the police), both placing a lot of trust in it, EWT may not be as accurate as the witnesses and the police like to think.  Fruzzetti et al 1992 concluded that thousands of people are convicted each year on the basis of inaccurate EWT and Wells et al (1998) investigated 40 American cases were people convicted by EWT were later acquitted by DNA evidence. 

Loftus (1974) highlighted this effect!  She got participants to act as jurors and decide the guilt or innocence of role playing thieves.  When evidence was merely circumstantial such as the suspect being seen entering the building where the crime took place only 18% were judged to be guilty.  However, when the testimony of an eyewitness was added who claimed to have seen the defendant commit the crime, this rose to 72%!!.  Even when the witness admitted that their eyesight was poor and that they were not wearing glasses at the time, 68% of jurors were still prepared to convict on their testimony alone!

In a classic American study carried out by Buckhout 1980, a 13 second film clip of a mugging was shown on TV.  An identity parade of six suspects was later shown and viewers asked to phone in and say who they thought had dunnit! 

Given that there were only six suspects, chance alone would suggest that 17% would get it right!  In fact only 14% identified the person correctly suggesting that EWT is not particularly accurate in some cases!  I will regale you with my own anecdotal evidence in class!!! (Something to look forward to there lol)!

Reconstructive nature of memory

The main models of memory, such as multistore, see memory has the storage of information in a fixed form that does not change over time.  So that a memory of falling off of your bike at the age of 6 and who helped, how much blood was spilt etc.  will be the same in 10 years time as it is today and as it was a few days after the event.   However, reconstructive theories believe memory to be flexible and constantly being altered in the light of our experience and with constant retelling.

Schemas

Schemas are packages of knowledge (according to Cardwell),  that we acquire through experience.  They help us to build up a picture of our World and enable us to make predictions about our day to day lives.   For example we will have a schema for funerals, so that when we are in the unfortunate position of attending one we are able to behave in accordance with social norms without having to read up on them first.  Our schema for funeral will exist even if we have never been to a funeral before, because we will have read about them, heard about them and seen them portrayed in soaps etc.  Similarly we will have schemas for going to weddings, restaurants, for sitting exams, going clubbing, romantic dates etc.  Imagine going on your first date with nor prior expectations of what is involved!!! 

Cohen (1993) suggested a number of ways in which schemas affect our memory.

1.       Selection: Information that does not fit current schemas is ignored.

2.       Abstraction: we are inclined to recall the overall gist and forget the detail.

3.       Interpretation: schemas provide existing knowledge to help us understand novel situations.

4.       Normalisation: memories are distorted to fit with our existing expectations.

5.       Retrieval: schemas (or schemata) help us fill gaps in our memory by making a best guess.

Think how some of these would tie in with reconstructing the scene of a crime!  For example, evidence suggests that minor details are not remembered accurately but are added later in line with what we would expect to have happened.

Research into schemas:  Bartlett’s War of the Ghosts (1932)  

Bartlett’s theory was unfashionable for many years but has recently been recognised as providing a valuable insight into the reconstructive nature of human memory.  His theory was based on Western recall of a native North American folk story.  He suggested that we make the following alterations in such cases:

·         Rationalisations: people tended to add material to justify parts of the story.

·         Omissions: parts of the story, particularly those difficult to understand, were left out.

·         Changes of order:  the storyline was rearranged in an attempt to make sense out of it.

·         Distortions of emotion: people added their own feelings and attitudes to the story.

 Mind Changers: Sir Frederic Bartlett

The War of the Ghosts

One night two young men from Egulac went down to the river to hunt seals and while they were there it became foggy and calm. Then they heard war-cries, and they thought: "Maybe this is a war-party". They escaped to the shore, and hid behind a log. Now canoes came up, and they heard the noise of paddles, and saw one canoe coming up to them. There were five men in the canoe, and they said:

"What do you think? We wish to take you along. We are going up the river to make war on the people."

One of the young men said,"I have no arrows."   

 "Arrows are in the canoe," they said.

"I will not go along. I might be killed. My relatives do not know where I have gone. But you," he said, turning to the other, "may go with them."

So one of the young men went, but the other returned home.    And the warriors went on up the river to a town on the other side of Kalama. The people came down to the water and they began to fight, and many were killed. But presently the young man heard one of the warriors say, "Quick, let us go home: that Indian has been hit." Now he thought: "Oh, they are ghosts." He did not feel sick, but they said he had been shot.

So the canoes went back to Egulac and the young man went ashore to his house and made a fire. And he told everybody and said: "Behold I accompanied the ghosts, and we went to fight. Many of our fellows were killed, and many of those who attacked us were killed. They said I was hit, and I did not feel sick."

He told it all, and then he became quiet. When the sun rose he fell down. Something black came out of his mouth. His face became contorted. The people jumped up and cried.      He was dead.

(from Bartlett, Remembering, 1932/1995, p. 65)

Being a native North American story the narrative contains words, concepts and ideas different to ones that as Westerners we are used to.    As a result when we are asked to retell the story we make alterations.  These are based on our own schemas, stereotypes and expectations.  

Look at the list of alterations Bartlett suggested (previous page) and try to spot examples of them in the participant’s version below:

War of the Ghosts: sample recall

Two men from Edulac went fishing. While thus occupied by the river they heard a noise in the distance.

"It sounds like a cry", said one, and presently there appeared some men in canoes who invited them to join the party on their adventure. One of the young men refused to go, on the ground of family ties, but he other offered to go.     

"But there are no arrows", he said.

"The arrows are in the boat", was the reply.

He thereupon took his place, while his friend returned home. The party paddled up the river to Kaloma, and began to land on the banks of the river. The enemy came rushing upon them, and some sharp fighting ensued. Presently some one was injured, and the cry was raised that the enemy were ghosts.

The party returned down the stream, and the young man arrived home feeling none the worse for is experience. The next morning at dawn he endeavoured to recount his adventures. While he was talking something black issued from his mouth. Suddenly he uttered a cry and fell down. His friends gathered round him.

But he was dead.

(from Bartlett, Remembering, 1932/1995, p. 66 -- transcript of a recall protocol taken after 20 hours)    

The story above is by way of illustration.  There is no need to learn the detail, only what it tells us!

Other examples of research into schemas

Brewer & Treyens (1981) got participants to wait one a t a time in a room for 35 seconds.  The room looked like an office and contained 61 items.  Most objects were ones you would expect to be in an office, others such as a skull, a brick and a pair of pliers, were not.  Later they were asked to recall the items in the office.   

Findings

Not surprisingly participants were most likely to recall the typical office fare, desk, chair etc.  Most of the errors were substitutions, i.e. people tended to include items such as pens and telephones that would be in the ‘schema for office’, but in this case weren’t.

Conclusion

Participants were using their schema for ‘office’ to fill in the gaps in their memory. 

Note:  this is a favourite experiment for A2 coursework!

Evaluation

Many of the participants recalled the skull, presumably not in most peoples’ schema for an office!  Schema plus tag theory attempts to explain this.  The idea being that we store our memory of the office with our schema for office, but attach a marker (or tag) to indicate any unexpected aspect.  For a topical example, peoples’ memories of Manchester United games may all seem pretty much the same and if asked to describe one 3 weeks ago you may struggle and have to rely on your schema for football to fill in the gaps.  However, if something out of the ordinary occurred such as United winning or not conceding a goal, then that will be tagged onto the memory and you will be better able to recall the details of the match.  (Important note, do not use this has an example.  We all know how many MUFC fans there are out there, including examiners!).

Stereotypes

Work in a similar way to schemas but concern people and our prejudices.  Main studies include

Allport & Postman (1947) who showed participants pictures of a white man with a razor threatening a black man on the subway.  Later, participants tended to recall the black man threatening the white. 

Cohen (1981) showed participants a video of a couple eating a meal.  They were told that either the woman was a waitress or a librarian.  This information later influenced the participants’ description of the woman.  I’ll leave their descriptions to your own stereotypical views.  (note:  the stereotype was more obvious if participants were told the person’s occupation after watching the video).

Summary of schemas and stereotypes

The theory suggests that we are only able to take in so much information at the scene of a crime or incident.  At a later date when we are asked to provide greater detail then we rely on past experience (schemas) and prejudices (stereotypes) to fill in the gaps.  We use expectations to reconstruct our memory.

Evaluation

The theory over emphasises the inaccuracy of our memory.

Schema theory provides no explanation of how schemas work.

Leading Questions...  (and a lesson in grammar)

This is a question, usually asked during the course of a police investigation, which unwittingly has an effect on the recall of information. 

Much of the research in the area has been carried out by Elizabeth Loftus (clearly a woman and as such needs to be referred to by the following personal pronoun: 'she.'  The photo yet again provides clear evidence that generally speaking female psychologists are more attractive than their male counterparts.  See later pictures of Bartlett, Tulving and co. for further evidence.

Loftus & Palmer (1974)

The researchers showed participants a series of slides of car crashes.  They were then asked ‘How fast the cars going when they bumped into each other?’  The verb (the doing bit) was substituted for other participants with words such as ‘smashed’ or ‘hit.’ 

Findings: the estimated speed varied according to the verb used.  ‘Smashed’ produced an average estimate of 41mph whereas ‘hit’ reduced the estimates to 34mph and to 32mph for ‘contacted.’

A week later participants were asked if there was broken glass from a headlight.  This time participants who had received the verb ‘smashed’ were more likely to recall seeing glass.

Conclusion

Loftus had shown how language and wording could influence a person’s recall of an incident.

Evaluation

Loftus had concentrated on minor details of the incident.  Research suggests that our recall of key details is not so prone to leading questions.

·         The study lacks ecological validity.  The use of clips does not recreate the emotion of a real life incident.

·         The study employed students who are hardly representative of the population as a whole.

Loftus & Zanni (1975)

The effects of wording can also be more subtle.  In a similar study participants were asked questions using either the definite article (‘the’) or indefinite article (‘a’ or ‘an’).  So for example: ‘Did you see the broken headlight?’ or ‘Did you see a broken headlight?’  Participants asked ‘the’ were twice as likely to recall seeing the broken headlight as those asked ‘a’.

Christianson & Hubinette (1993) found that fear does have an effect.  They asked people involved in real bank robberies, either as victims or as onlookers, about the incident.  The recall of the victims was more accurate than that of the onlookers, suggesting the stress of the situation had aided recall.  The better recall was still present 15 months later.

Evaluation of Loftus’ Research

Lack of ecological validity (as already stated).  Other research has found that when participants are led to believe the incident they’ve witnessed is real then their recall is more accurate. 

Similarly recall may be less accurate because participants know their response will not have serious consequences for others.  Participants were shown video footage of a bank robbery and later asked to spot the robbers in an identity parade.  Those led to believe the footage was genuine were more likely to recognise the right person.

Loftus tends to use a forced choice format in which participants have to choose between one option or another (similar to multiple choice).  Some research suggests that recall is more accurate if participants have an open choice, or more importantly have the option to give no answer at all.

Other factors that may affect accuracy of EWT

Anxiety

High levels of anxiety can have a negative impact on recall:

In a meta-analysis of studies Deffenbacher et al (2004) found that heightened emotion had led to less accurate recall by witnesses.

High levels of anxiety can improve recall

Christianson and Hubinette (1993) questioned 110 witnesses to 22 real bank robberies and found that those who had been threatened during the raids had a more accurate recall of events. 

The inverted U relationship or Yerkes-Dodson law

This relationship states that stress or anxiety increases performance up to an optimal point.  After that, further increases in anxiety lead to a falling off of performance.  This also seems to apply to the relationship between anxiety and recall.

In the studies mentioned above it seems reasonable to assume that research showing improving performance were describing patterns to the left of the graph and those showing impairment were describing patterns to the right. 

Weapons focus

In some ways related to anxiety, it isn’t really surprising that faced with a knife or gun toting maniac you’re most likely be focusing you’re attention on the weapon rather than the attacker.  Loftus et al 1987 got participants to listen to a squabble between two people, one sounding more violent than the other.  In the quieter affair a man with greasy hands emerges holding a pen.  Following the noisy, violent sounding incident a man emerges with a blood drenched knife.  Participants could accurately recall the identity of the ‘pen-fiend’ on 49% of occasions but the knifeman on only 33%.  In a follow up Loftus recorded eye movements and found the focus of attention was the knife, diverting attention from the identity of the perpetrator. 

Age

The relationship between age and recall of events is also more complex than may be expected.  You can probably guess that the older we get the more fragile our cognitive (and other functions) so generally wrinklies tend to make less reliable eye witnesses.  However, evidence also suggests that the young are prone to errors too.

Young people and EWT

Poole and Lindsay (2001) got children of varying ages (three to eight) to watch a science demonstration following which they listened to a story which contained some of the science material but also some new information.  Later when they were questioned about the science demonstration it was found that they threw in some of the story as well.  In a follow up they were asked to consider where they had got the information from (the demonstration or the story).  The older children could mostly do this successfully but the ones in the younger age group were less able to distinguish the source of the information.  Poole and Lindsay therefore concluded that since young children are poor at ‘source recognition’ they are unlikely to make for good eye witnesses. 

Flin et al (1992) staged an incident (what it was I’ve been unable to find out) and questioned children and adults about it a day later and again five months later.  Both groups (young and old) performed equally well the following day but after five months the children’s group had forgotten significantly more suggesting the EWT of children becomes less reliable over time.  NOTE: this clearly has practical implications for children being questioned as soon as possible after an event. 

Along similar lines Gordon et al (2001) believed that children can make good witnesses but that they’re particularly prone to suggestion.  Relate this to leading questions: children could be especially susceptible!

Old people and EWT

Memon et al (2003) reworked the Flin et al study (above) with older two age groups (6-33) and (60 to 82).  When questioned 35 minutes after an event age had little effect on accuracy of recall, however, a week later the older age group had declined significantly in their accuracy.

Yarmey (1993) found little difference in accuracy of age-related recall but a difference in confidence of recall. He got a young woman to stop people in the street and chat to them for 15 seconds.  She did this with 651 participants of varying age.  Two minutes later the participants were stopped again and asked to recall the physical characteristics of the woman.  All age groups performed similarly but younger age groups were significantly more confident in their recall.

Methodological issue

Most research in psychology is carried out on undergraduate students (18-22 year olds) and memory is no different.  This is a particular issue when it comes to studying age differences since most of the materials used in the above studies would have been designed for this age group, i.e. the photographs of college students.  Perhaps the better recall of younger groups is actually due to them recognising people from their own age group! 

To test this possibility, Anastasi and Rhodes (2006) tested three age groups (teenage/twenties, thirties/forties and fifties to seventies).  Each participant was shown 24 photographs of a mixture of age groups.  Later they were shown 48 photographs (24 the same as before and 24 different photos).  The participants had to say which ones they’d been shown earlier. 

It was found that generally the young and middle-aged group were better at recall, however, all three groups were better at recognising photographs of their own age group. 

A similar rule also applies to race.  We are better at recognising people from our own ethnic group than from others, so yes, Caucasian faces do all look the same to the Chinese!

Importance

Most memory research is carried out under laboratory conditions. 

However, lab experiments are not very realistic.  There is no emotional factor that you get at the site of a real incident and similarly there is no importance in getting the facts right.  Foster et al (1994) showed two groups of people a video of a bank robbery followed by an identity parade.  Half were told it was part of an experiment whilst the other half were told it was genuine footage and that their answers would influence the trial.  This second group were significantly more likely to chose the right culprits from the parade.

The cognitive interview (CI)

This was based largely on the work of Elizabeth Loftus and other psychologists, following their theoretical work into memory and EWT.  Forensic psychologists combined various ideas and designed a more effective way of questioning witnesses that has been shown to produce more reliable recall of events.  Fisher and Geiselman (1992) designed the cognitive interview.

The technique is based around four main components:

Evidence for the cognitive interview

Geiselman et al (1985) got participants to watch a video of a violent crime.  A few days later they were interviewed in one of 3 ways: standard police interview, cognitive interview or under hypnosis.  The cognitive interview was found to trigger the most accurate recall. 

Note: hypnosis is not as effective as films would lead us to believe (the so-called Hollywood effect).  Witnesses often do recall more under hypnosis and are more confident in their recall.  Unfortunately much of what they recall is inaccurate.  Additionally, their confidence in what they recall can be very influential in court room situations, particularly with jurors so is doubly dangerous. 

Kohnken et al (1999) carried out a meta-analysis of 53 other studies and found that the CI could elicit an average of 34% more detail than the standard interview and crucially without the loss of accuracy you get with hypnosis. 

Interestingly, when the four components of the interview are used individually, e.g. recall in a different order, there is little gain over the standard interview.  It’s only when two or more components are used that there is significant improvement in recall. Milne and Bull (2002).  The report everything and context reinstatement combinations appear most effective. 

But: it is difficult to compare studies carried out in different countries and even between different police forces within a country since there are now so many variations on the CI.  For example in the UK the Merseyside force use pretty much the original Fisher and Geiselman design whereas Thames Valley Police (Morse and Lewis no doubt) tend to drop the ‘reinstating context.’ 

One criticism of the technique is that it tends to be too time-consuming in practice. 

Young children seem to find the instructions confusing and as a result produce less reliable recall than with standard police interviews.  Geiselman (1999) recommends that the CI is only used on children aged eight and over. 

Enhanced cognitive interview

There is a slightly modified version in which, for example, interviewers use ‘open’ rather than ‘closed’ or ‘leading questions’ and are encouraged to follow the witnesses train of thought rather than get them to recall incidents in chronological order.

Using this enhanced cognitive interview method Miami Police (*Crockett and Tubbs no doubt), reported an increase of 46% in amount of detail recalled by witnesses, where corroborative evidence was available 90% of this additional testimony was shown to be accurate. 

*Note Crockett and Tubbs are not researchers, so please do not use their names in answers!!!!  Anybody seen re-runs of “Miami Vice?”

Example questions on the CI:

Discuss the use of the cognitive interview in obtaining evidence from eye witnesses (12 marks)

Trevor is a police officer.  When he interviews witnesses he generally asks lots of short, closed questions.  Because he is always busy he avoids general questions and tends to interrupt if witnesses don’t recall what he wants to know.  He claims his habit of asking questions ‘in no particular order’ keeps witnesses on their toes and stops them elaborating on what really happened.

Identify the problems with Trevor’s current method of interviewing and suggest changes he could make to improve the accuracy of EWT.  (6 marks)

Strategies for memory improvement

Another practical application of memory research is helping people to remember more effectively, for example in preparation for examinations.  My use of photos of Morse and Miami Vice on the previous page would be one example of a visual strategy to trigger recall of Thames Valley and Miami police forces.  A few other ideas follow:

Organisation is crucial

To some extent all the methods we’ll consider involve organisation of the material to be recalled:

1. Verbal mnemonics use words to aid recall

There are a number of different types:

2. Visual imagery Mnemonics

Again this is based on the organisation of things to be recalled.  For example if we want to recall things in order first, second, third etc.  First we associate each number (one, two, three) with something that rhymes (verbal mnemonics)

 One-bun            Two-shoe          Three-tree         Four-door          Five-hive           Six-sticks …

Now imagine you want various items from Siansburys and ideally you want to recall them in the order you’ll walk around the store to save time back-tracking.  Items in order for me will be tomatoes, feta cheese, wine, bread, olives

I simply visualise (imagery) tomatoes in a bun (one), cheesy smelling shoe (two), wine in a tree (three), etc…

A favourite method used by stage memory people (there must be a technical term for them) is to visualise a route such as landmarks in the centre of London and then tag items to be recalled to these.  On recall they visualise retrace their steps around the landmarks. 

Visual imagery of this sort seems to work better with concrete nouns (food items, stationery etc) rather than with more abstract terms such as hope or conceit etc.  Paivio (1965) believed this was because concrete items are encoded both verbally and visually whereas abstract words tend to be difficult for us to encode in a visual format (try to visualise ‘conceit’).  Paivio referred to this as the dual coding hypothesis.  (Bower 1972) gave participants 100 cards each with two unrelated words.  One group simply memorised the words others were asked to produce a visual image linking the two words (e.g. door and cat).  When cued (given the first word e.g. door) the visual imagers were far more likely to recall the second word (80%) than the non-imagers (45%).

Mind mapping is also an example of visual imagery enhancing memory (Buzan 1993).

3. Cues and context

As already mentioned we tend to recall things better when we’re either in a similar state of mind to when we learned them or when we are in the same or similar place. 

a. Context dependent and state dependent learning/forgetting

Godden & Baddeley (1975) gave deep sea divers lists of words to remember.  Some learned them on the beach the others under 15 feet (4.5 metres) of water.

Recall was best when the divers recalled the words in the same environment as they’d learned them.  Context (the environment) is acting as the cue.  Abernathy (1940) found that psychology students performed better when tested by their usual teacher in the same room as they had learned the material.

b. State dependent

Our state of mind when learning can also act as a cue.  The classic example is not remembering what you did at the party the night before due to amount of alcohol consumed, but being able to remember all the embarrassing details the next time you’re in a similar state (of mind!).  By the way this is Goodwin et al (1969), not personal experience!  For example they found that participants who had hidden money or alcohol when drunk and were unable to remember where the next day, were able to find it the next time they were drunk.  Other studies have found similar results with the effects of marijuana and barbiturates.  In these cases the cues are internal reflecting psychological or physiological states.

c. Encoding specificity principle:

This sounds complex but is really about as simple as it gets!  Tulving (1979), found that the closer the cue to the target word the better our recall.  Not exactly rocket science!  For example in trying to recall ‘Ramones’ a clue like ‘Ram Jams’ or ‘Ramrods’ is more likely to trigger the correct response than ‘Abba’!

Organisation and/or elaboration?

As already suggested when we produce mnemonics to aid memory we are organising the material which may explain why we remember it so much better.  However, creating mnemonics also requires that we elaborate material or process it at a deeper level.  So for example when we pair tomatoes with bun or feta cheese with shoe we are creating visual images of the words which, according to Craik and Lockhart’s Levels of Processing theory (mentioned earlier) means we are processing at a deeper level.  Similarly with a mind map, we are looking for connections or creating visual representations of the material being learned. 

Organisation is also clearly vital since our LTM is a hooooooooge store of information.  Producing a structured and well organised store will allow for more efficient location of information.  Cognitive psychologists do like computer analogies so liken it to organisation of your files on your PC. 

Most of the ideas above are simple and used on their own are going to be of limited practical value.  Herrmann (1991) believed we need to take a multi-modal approach and use a variety of methods that suit us personally.  Similarly Matlin (1998) coined the phrase ‘meta-memory’ an awareness of our own memories and the strategies that work for us. 

A few ideas... Use them!