Cognitive Psychology Memory. Student workbook

Transcription

1 Cognitive Psychology Memory Student workbook Name:... Teacher:... 1

2 Specification Requirements Memory Candidates will be expected to demonstrate: Knowledge and understanding of concepts, theories and studies in relation to cognitive psychology Skills of analysis, evaluation and application in relation to social psychology Knowledge and understanding of research methods associated with this area of psychology Knowledge and understanding of ethical issues associated with this area of psychology. Content outline Memory The multi-store model of memory: sensory register, short-term memory and long-term memory. Features of each store: coding, capacity and duration. Types of long-term memory: episodic, semantic, procedural. The working memory model: central executive, phonological loop, visuo-spatial sketchpad and episodic buffer. Features of the model: coding and capacity. Explanations for forgetting: proactive and retroactive interference and retrieval failure due to absence of cues. Factors affecting the accuracy of eyewitness testimony: misleading information, including leading questions and post-event discussion; anxiety. Improving the accuracy of eyewitness testimony, including the use of the cognitive interview. 2

3 Models and Types of Memory The Multi-Store Model of Memory 3

4 Coding,Capacity and Duration of STM and LTM WHAT IS A MODEL? WHAT IS MEMORY? If we could not retain and use information that we have already discovered, it would mean for every new experience we would have to process huge amounts of information, which could be very costly in the terms of the time it might take. EXAMPLE Brian was on holiday in Africa. He was sitting by a lake, watching some beautiful creatures flying above the surface of the water. He was not sure what they were, but they looked almost translucent, reflected in the sunlight. Then he noticed a ripple on the water, and suddenly something long started to appear. It was green in colour and looked quite shiny. Whatever it was it seemed to be getting longer as it approached him. Then he saw what looked like two beady little eyes on the top of what must have been its head, and they were looking at him. Suddenly it came out of the water towards him, its long body propelled by four short, thick legs, and it flicked it s long, leathery tail. It s mouth opened, and snap. In this example If Brian had been able to store information in his memory, he would be aware that lakes in Africa are likely to be inhabited by crocodiles. As he had to process each piece of information as he received it, the time taken to realise that the crocodile is not friendly was too long to enable Brian to save himself. TYPES OF MEMORY 4

5 1) SENSORY MEMORY 2) SHORT TERM-MEMORY 3) LONG TERM MEMORY 5

6 ... Factors Affecting Memory... 6

7 Information which is rehearsed (or repeated) is more likely to be remembered. KEY FEATURES OF THE MULTI-STORE MEMORY 3 different types of memory Model describes these as memory stores SM, STM, & LTM Any stimulus you come across has been in one or more of these stores in this sequence! Each store retains a different of info, in a different and for a different length of. CAPACITY (AMOUNT OF INFO) 7

8 ENCODING (DIFFERENT WAY) DURATION (TIME) SENSORY MEMORY ENCODING. The SM takes info from one of the sense organs and holds it in that same form. ICONIC MEMORY ECHOIC MEMORY 8

9 SENSORY MEMORY - CAPACITY AND DURATION Sperling (1960): 9

10 SHORT TERM MEMORY ENCODING & CAPACITY. Conrad (1964) Visually presented students with letters one at a time Found that: letters which are acoustically similar (rhyming) are harder to recall from STM than those which are acoustically dissimilar (non-rhyming) WHAT DOES THIS SUGGEST? Evaluation of CODING. One limitation of Baddeley s study was that it used quite artificial stimuli rather than meaningful material. The word lists have no personal meaning to the participants. This means that we should be cautious about generalising the findings to different kinds of memory task. For example, when processing more meaningful information, people may use semantic coding for STM tasks. What does this suggests about the findings? 10

11 SHORT TERM MEMORY - CAPACITY Jacobs (1887) He wanted to find out how much information can the STM store? He devised a technique to measure digit span. The researcher gives, for example, 4 digits and the participant must recall these in the correct order out loud. If this is correct he then reads out 5 digits and so on until the participants cannot recall the order correctly. This determines the individual s digit span. Jacobs found that the mean span for digits across all participants was 9.3 items and mean span for letters was 7.3. SHORT TERM MEMORY EXTENDING IT. Chunking involves making the info more meaningful, through organising it in line with existing knowledge from your LTM - in this case, of abbreviations for qualifications. Evaluation of Capacity One limitation of Jacob s study is that it was conducted a long time ago. Why would this be considered to be a limitation? However, the results of this study have been confirmed by other pieces of research increasing its validity. 11

12 One limitation of Miller s research is that he may have overestimated the capacity of the STM. For example Cowan (2001) reviewed other research and concluded that the capacity of the STM was only about four chunks. This suggests that the lower end of Miller s estimate (five items) is more appropriate than seven items. SHORT TERM MEMORY DURATION How long can you retain a new phone number before you have to write it down? if you didn t rehearse it? n The duration for which STM can retain info is temporary a very short time n Not much research interest of this aspect, but n some findings suggest only a few seconds before it fades/decays (unless we rehearse it) PETERSON & PETERSON (1959) Their findings suggest that our STM fades in under a half a minute if we are not rehearsing it: 12

13 RESULTS Evaluation A limitation of Peterson and Peterson s study is, like Baddeley, the stimulus material is artificial. Trying to memorise consonant syllables does not reflect most real-life memory activities where what we are trying to remember is meaningful. So we might say that this study lacked external validity. Why? 13

14 However, we do sometimes try to remember fairly meaningless things, such as phone numbers, so the study is not totally irrelevant. LONG TERM MEMORY ENCODING BADDELEY (1966) Presented lists of 10 short words one at a time Some lists were semantically similar, others not Tested immediately & then after 20 min delay Found that after 20 mins, they did poorly on the semantically similar words WHAT DOES THIS SUGGEST? LONG TERM MEMORY CAPACITY AND DURATION Capacity = potentially unlimited. Duration = anything up to a lifetime. (minutes to years) Difficult to test exact duration, but 14

15 BAHRICK (1975) use page 46 to fill out procedure and results. Evaluation One strength of Bahrick s study is that it has higher external validity. Real-life meaningful memories were studied. When studies on LTM have been conducted with meaningless pictures to be remembered, recall rates were lower (Shephard, 1967). The downside to such real-life is that confounding variables are not controlled for, such as the fact that Bahrick s participants may have looked at the yearbook photos and rehearsed their memory over the years. Can you think of any other issues with the Bahrick study? 15

16 EVALUATION OF MULTI-STORE MODEL GLANZER AND CUNITZ (1966) THE SERIAL POSITION EFFECT (GLANZER AND CUNITZ, 1966) PRIMACY EFFECT RECENCY EFFECT : BRAIN SCANNING RESEARCH 16

17 n MRI scans show which parts of the brain are being used when certain tasks are carried out: These findings back up the existence of different stores for different memories. In your own words; How do these findings back up the existence of different stores for different memories? 17

18 Evaluation of the Multi-Store Model of Memory 18

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21 Types of Long Term Memory 21

22 Types of Long Term Memory Tulving (1985) was one of the first cognitive psychologists to realise that the Multi-store model s view of LTM was too simplistic and inflexible. Tulving proposed that there was infact three LTM stores, containing different types of information in each. Before we discuss these types you will be taking part in a quiz What is the capital of France? What is 7 X 7? What is the chemical symbol for Oxygen? When was the battle of Hastings? What date is Halloween? Who wrote Harry Potter? What is the French for Dog? Can you identify a link between these questions? What do the answers have in common? What is your earliest memory? How many people can you name from your class at Primary School? What did it feel like on your first day at TGS School and Sixth Form? Who was your first crush? What was your favourite book when you were 11? What is your favourite song? Who was your favourite teacher last year? Can you identify a link between these questions? What do the answers have in common? Can you ride a bike? Will you be learning to drive this year? Can you play an instrument? If so what grade are you, if any? Do you take part in any sport? Are you better now than when you first started? Can you touch your elbow with your tongue? Can you identify a link between these questions? What do the answers have in common? 22

23 These types of question all refer to different types of information that we remember and different types of LTM. They are called semantic memory, episodic memory and procedural memory. Semantic Memory 23

24 Episodic Memory 24

25 Procedural Memory 25

26 Evaluation Clinical Evidence Several cases of patients who have suffered brain damage to their hippocampus & have memory deficits: Clive Wearing and HM Their memory loss tends to be selective These are very famous case studies. Clive Wearing Henry Molaison (HM) Episodic memory in both of these men was severely impaired as a consequence of amnesia. They had great difficulty recalling events that had happened from their pasts. However, their semantic memories were relatively unaffected. For example, they still knew the meaning of words. So HM would not be able to recall stroking a dog half an hour earlier and could not remember having owned one in the past, but he would never need to concept of dog explained to him over and over again. Their procedural memories were also intact. They both knew how to tie their shoelaces, how to walk and speak, and in Clive Wearing s case (he was a professional musician), how to read music, sing and play piano. How is this evidence for different types of LTM? From this evidence does it suggest that these different memories are stored in the same place? 26

27 Neuroimaging Evidence There is also evidence from brain scan studies that different types of memory are stored in different parts of the brain. For example, Tulving (1994) got their participants to perform various tasks while their brains were scanned using a PET scanner. They found that episodic and semantic were both recalled from an area of the brain known as the prefrontal cortex. This area is divided into two areas, one on each side (or hemisphere) of the brain. The left prefrontal cortex was involved in recalling semantic memories. Episodic memories were recalled from the right prefrontal cortex. Procedural memories, however, were recalled from the cerebellum and the basal ganglia. Type of Long Term Memory Semantic Location stored in brain Episodic Procedural Why is using brain scans a strength? What do the results of these brain scans suggest? 27

28 Real life applications Being able to identify different aspects of LTM allows psychologists to target certain kinds of memory in order to better people s lives. Belleville (2006) demonstrated that episodic memories could be improved in older people who had a mild cognitive impairment. The trained participants performed better on a test of episodic memory after training than a control group. Episodic memory is the type of memory most often affected by mild cognitive impairment, which highlights the benefit of being able to distinguish between types of LTM. What do you think the benefit of this is? Apply it Clive Wearing suffers from a severe form of amnesia that resulted from a viral infection that attacked his brain, damaging the hippocampus and associated areas. Before this infection Clive was a world-class musician and he can still play the piano brilliantly and conduct a choir but he can t remember his musical education. He can remember some other aspects of his life before his infection, but not others. For example, he know he has children from an earlier marriage, but cannot remember their names. He recognises his second wife, Deborah, and greets her joyously every time they meet, believing he has not seen her in years, even though she may have just left the room for a few minutes. Questions 1) Can you explain why Clive will play the same piece of music over and over again? 2) Imagine you been asked to test Clive Wearing s memory to see which of Tulving s three types of LTM are intact. Explain how you might do this. 28

29 The Working Memory Model 29

30 THE WORKING MEMORY MODEL (BADDELY, 1974) Used the term Working Memory to refer to that bit of information you are using while working on a complex task which requires you to store information as you go along; Eg. When you are calculating a complex sum such as , you add 21 and 12 then hold that number in your memory before adding the final number. THESE ARE CALLED SLAVE SYSTEMS 30

31 Baddeley and Hitch believed the STM was not just one store but a number of different ones. Why? If you do two at the same time and they are both visual tasks, you perform less well than if you do them separately. If you do two things at the same time where one is visual and the other involves sounds then there is no interference. You do them as well simultaneously as would separately. This suggest that there must be one store for visual processing and one for processing sounds. THE CENTRAL EXECUTIVE EPISODIC BUFFER 31

32 THE PHONOLOGICAL LOOP Deals with auditory information and the order of information Baddeley(1986) divided it into two components: AUDITORY STORE: THE ARTICULATORY CONTROL PROCESS: THE VISUO-SPATIAL SKETCHPAD 32

33 TASK Work out how many windows are in your house How did you do it? Discuss your answer with the person next to you Did you use similar strategies? How will each of the Working Memory components contribute to the completion of the TASK? Phonological Loop Visuo-spatial Sketchpad Central Executive 33

34 STUDIES TO SUPPORT CENTRAL EXECUTIVE Activity in the CE should be increased when an individual has to perform 2 tasks simultaneously (dual-task) rather than one after the other (single task). Bunge (2000) Used fmri scans to see which parts of the brain are most active when participants were carrying out 2 tasks. The same brain area areas were active during dual- or single task conditions. However, STUDY TO SUPPORT PHONOLOGICAL LOOP BADDELY, THOMPSON AND BUCANNAN (1975) WORD LENGTH EFFECT. 34

35 Presented words for very brief periods of time. One condition 5 words, one syllable, familiar. Two condition: 5 polysyllabic words. Average correct recall over several trials showed participants remembered the short words much better. This is the word length effect. WHAT DOES THIS TELL US ABOUT THE PHONOLOGICAL LOOP? The phonological loop explains why the word- length effect occurs the fact that people cope better with short words than long words in working memory (STM). Therefore ARTICULATORY SUPPRESSION Baddeley et al also found that the word length effect disappeared under conditions of articulatory suppression. Inhibiting memory performance by speaking while being presented with an item to remember. 35

36 DUAL-TASK PERFORMANCE Baddely and Hitch felt that STM was not just one store but a number of different stores. Research shows that if you do 2 things at the same time and they are both visual tasks - You perform less well than if you do them separately. However, if you do 2 tasks at the same time where one is visual and the other is auditory (sound), then there is no interference. You do them as well simultaneously as you would do them separately. What does this suggest? CASE STUDY EVIDENCE 36

37 The Case of KF In the 1970s, KF was in a motorcycle accident, resulting in brain damage to his left occipiatal lobe (pictured right). STM was damaged, but LTM was normal He remembers words better if presented visually as opposed to auditorally. What does KF s case study tell psychologists about memory? Which model does it support? 37

38 Evaluation of the Working Memory Model 38

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41 Explanations for Forgetting Interference Theory and Retrieval Failure 41

42 Explanations for Forgetting Interference Theory According to this theory there are two types of interference. Proactive interference is when previous learning interferes with later learning. Retroactive interference is when later learning disrupts earlier learning. For example, if you learned a set of facts about India, and I then asked you to learn a set of facts about China, you could experience interference in one of two ways. The facts about India could disrupt your learning of China (proactive interference) or the new facts about China could alter what you know about India (retroactive interference). A common everyday example of proactive interference is when you rearrange the location of items in a room. You may keep going back to the place where items used to be instead of where they are now! Types of Interference Elaborated explanations Interference Proactive Interference (PI) Retroactive Interference (RI) Defintion This occurs when an older memory interferes with a new one (pro in this context means working forwards, from old to new). For example, your teacher has learned so many names in the past that she has difficulty remembering the names of her current class. This occurs when a newer memory interferes with an older one (retro meaning working backwards). For example, your teacher has learned so many names this year that she has difficulty remembering the names of the students last year. Apply It To illustrate the difference between the two types of interference, imagine you have learned to drive a car in the UK (you may not have to have imagined this, of course). You will have learned to drive on the left hand side of the road. You then fly to Spain for your holidays and hire a car. Driving out of the airport, you narrowly avoid causing an accident because you failed to drive on the right. This is one example of interference. You return to the UK and, driving out of the car park, you find yourself in the right hand lane. This is another example of interference. Question Can you identify which is the proactive interference and which is retroactive interference. Explain why you made this choice? 42

43 Evidence for Interference Theory Underwood &Postman (1960) used a paired associate learning task to test the effect of interference. Participants are asked to learn a series of word pairs, so that they can be presented with the first word (the stimulus word), and recall its paired word (response word). They are then given another list of word pairs to learn which have the same stimulus word, but a different response word. Participants have their recall tested on either the first or second list of words. Example List A List B List C Cat Tree Stone Candle Whale Cloth Book Fork Jail Plant Tank Claw Water Market Gold Track Lemon Kettle Dish Cane Swamp Flask Picture Mast Cigar Jelly Nail Animal Nurse Pencil Participants had to learn word pairs from List A and B Eg. Cat Tree, Candle Whale. They then had to learn a second list which interferes with the first list; word pairs from List A and C; Eg Cat Stone, Candle Cloth. In the task they are given the first word of the pair from List A. They are then asked to recall the corresponding word from either List B (Retroactive Interference) or List C (Proactive Interference) A control condition is used to see what recall will occur when there is no intereference. Which condition do you think performed best and give reasons for your answer? 43

44 Results As expected, recall of the response words is poorer, and affected by both previous learning (proactive) and later learning (retroactive). However, this effect is only present when the same stimulus words are used in both lists. Research suggests that interference only plays a part when the two stimuli are very similar. How often would this apply to real life? Effects of Similarity In both cases of retroactive and proactive interference, the interference is worse when the memories (or learning) are similar. McGeoch and McDonald (1931) They studied retroactive interference by changing the amount of similarity between two sets of materials. Participants had to learn a list of words until they could remember them 100% accurately. They then learned a new list. There were six groups of participants who had to learn different types of lists. Group 1 Synonyms words with the same meanings of the originals. Group 2 Antonyms words with the opposite meanings of the originals. Group 3 Words unrelated to the original ones. Group 4 Nonsense Syllables. Group 5 three-digit numbers. Group 6 No new list these participants just rested. Findings 44

45 Using the graph explain the results of the study in your answer you must refer to what produces the worst recall, what produces the best recall and what it suggest about the effects of similarity. Evaluation of Interference Theory Evidence from Lab Studies Interference in memory is probably one of the most consistently demonstrated findings in the whole of psychology. Literally thousands of lab experiments have been carried out into this explanation for forgetting, such as McGeoch and McDonald s research. Most of these studies show that both types of interference are very likely to be the common ways we forget information from LTM. Explain why this is a strength. Articifical Materials There is much greater chance that interference will be demonstrated in the lab than in real life situations, for one good reason. The stimulus material used in most studies are lists of words. The task facing the participants is to learn these lists. Learning lists of words is actually more realistic than remembering lists of consonant syllables. (such TZK). But this is still quite a distance from the things we learn and try and remember in everyday life eg. People s faces, birthdays, the ingredients to your favourite recipes, details of psychological research studies (!). Why is this a limitation for Interference Theory? Explain your answer. 45

46 Real Life Studies Some research studies have considered interference effects in more everyday situations. Baddeley and Hitch (1977) They wanted to find out if interference was a better explanation than just the passing of time. In their study they asked Rugby players to try and remember the names of the teams they had played so far in the season, week by week. Because most of the players had missed some games, for some the last team they played might have been two weeks ago, or three, or even more. The results very clearly showed that accurate recall did not depend on how long ago the matches took place. More important was the number of games they had played in the meantime. So a player s recall of a team from three weeks ago was much better if they had played no matches since then. If they had played a lot this would interfere with their recall. Does this study provide support for Interference theory? Why? Is it better that this was a natural experiment? 46

47 Explanations for Forgetting Retrieval Failure The reason why people forget information may be because of insufficient cues. When information is initially placed in memory, associated cues are stored at the same time. Forgetting in LTM is usually down to retrieval failure (lack of accessibility, rather than availability) This is failure to find an item of information because you have insufficient clues or cues. If someone gives you a hint then the memory might pop back into your head, but in the meantime you are faced with a blank. It is possible that you have a vast amount of memories and could access them if only someone would provide the right cues. Encoding Specificity Principle (ESP) Tulving (1983) research into retrieval failure and discovered a consistent pattern to the findings. He summarised this pattern in what he called the ESP. This states that if a cue is to help us to recall information then it has to be present at encoding (when we learn the material) and at retrieval (when we are recalling it). It follows from this that if the cues available at encoding and retrieval are different (or if cues are entirely absent at retrieval) there will be some forgetting. Some cues are linked to the material-to-be-remembered in a meaningful way. For example, the cue STM may lead you to recall all sorts of information related to short-term memory. Other cues are encoded at the time of learning but not in a meaningful way. There are 2 types of cue; External Cues Context-Dependant Learning Internal Cues State-Dependant Learning Context-Dependent Forgetting Abernethy (1940) Arranged for a group of students to be tested prior to a certain course beginning. Tested weekly Some student tested in their teaching room with the same instructor Some in same room but different instructor. Some in different room with same instructor. Some in different room, different instructor. Which group do you think performed best and why? Results 47

48 Those tested by same instructor in the same room performed the best. This is because familiar things and surroundings (room and instructor) acted as memory cues. Look around you. Does anything trigger a memory? If so, then it s acting as a cue. Godden and Baddely (1975) They carried out an interesting study of deep sea divers working underwater. In this it s crucial a matter of life and death for divers to remember instructions given before diving about their work underwater. In this study divers learned a list of words with underwater or on land and then were asked to recall the words either underwater or on land. This, therefore, created four conditions. Group 1 Learn on land Recall on land Group 2 Learn on land Recall underwater Group 3 Learn underwater Recall on land Group 4 Learn underwater Recall underwater Findings In two of these conditions the environmental contexts of learning and recall matched, whereas in the other two they did not. Accurate recall was 40% lower in the non matching conditions. Explain what the recall was 40% lower in the non-matching conditions. HINT Think about ESP if you are stuck. Do these studies give support for Context-Dependent learning? Why? 48

49 State-Dependent Forgetting If we were to learn something when we feel happy / sad / drunk, we could remember this information again when we are in the same mental state, i.e. happy / sad / drunk, but not when we are in another state of mind. For example: - We would remember a lot of bad things when in a bad mood. - We would forget sad events when we feel happy. Carter and Cassaday (1998) They looked at the effect of anti-histimines. They gave anti-histimines to their participants. They had a mild sedative effect making the participants slightly drowsy. This creates an internal physiological state different from the normal state of being awake and alert. The participants had to learn list of words and passages of prose and then call the information, again creating four conditions. Group 1 Learn on the drug recall when on it Group 2 Learn on drug recall when not on it Group 3 Learn not on drug recall when on it Group 4 Learn not on drug recall when not on it Findings In the conditions where there was a mismatch between internal state at learning and recall, performance on the memory test was significantly worse. So when the cues are absent (for example, you are drowsy when recalling information but been alert learning it) then there is more forgetting. Goodwin (1969) Found that people who drank a lot often forget where they have put things when they are sober. However, they could recall the locations when they are drunk again. Miles and Hardman (1998) Found that people who learned a list of words while exercising on an exercise bike remembered them better when exercising rather than at rest. What do the results of these studies suggest? Explain your answer 49

50 Interference or Cue-Dependant Forgetting? It is shown that interference does cause forgetting but only when the stimulus is paired with two difference responses. There conditions are rare in everyday life so therefore interference only explains a limited range of forgetting. Furthermore, it seems that it s not the most important explanation for forgetting either. Tulving and Psota (1971) Participants were given 6 different word lists to remember, each consisting of 24 words divided into 6 different categories. (so over the 6 lists there were 36 categories, such as kinds of tree and names of precious stones etc) After each list was presented, participants were asked to write down as many words as they could remember and this was a free recall. After all the lists were presented there was final total free recall (of all the lists they had learned). Then the participants were given the category names and again asked to recall all the words from all the lists so therefore this was a Cued Recall Some participants only learned one list, some two and so on. Findings According to Interference theory, the more lists a participants had to learn the worse their performance should become. This is exactly was T & P found evidence of Retroactive Interference. However, when participants were given cued recall, the effects of interference disappeared. Participants remembered about 70% of the words they were given regardless of how many lists they had been given. What do the results of this study suggest? 50

51 Retrieval Failure Evaluation Supporting Evidence There has been an impressive range of research supporting retrieval failure as an explanation for forgetting. The studies by Godden and Baddeley; Carter and Cassaday are excellent examples of this research. In fact, one prominent memory research, Michael Eyesenck (2010), goes as far to argue that retrieval failure is perhaps the main reason for forgetting in LTM. This is a strength because supporting evidence increases the validity of an explanation. This is especially true when the evidence show that retrieval failure occurs in real-life situations as well as in the highly controlled conditions of the lab. Why is having lab evidence and real life evidence a strength? Questioning the Context Effects Baddeley (1997) argues that the context effects are actually not very strong, especially in real life. Different contexts have to be very different indeed before an effect is seen. For example it would be very hard to find an environment as different from land as underwater. In contrast, learning something in one room and recalling it in another is unlikely to result in much forgetting because they environments are generally not different enough. This is a limitation because it means that the real-life applications of retrieval failure due to contextual cue don t actually explain much forgetting. Recall versus Recognition The context effect may be related to the kind of memory being tested. Godden and Baddeley (1980) replicated their underwater experiment but used a recognition test instead of recall. Participants had to say whether they recognised a word read to them from the list, instead of having to retrieve it themselves. When recognition was tested there was no context dependent effect; performance was the same in all four conditions. This is a limitation of context effects why? Explain your answer 51

52 Apply It Smell can act as a context-related cue to memory as shown in a study by John Aggleton and Louise Waskett (1999). They based their study on a museum in the northern city of York, which was called Jorvik in Viking times. There is an underground museum in York where you can walk around the 1000 year old ruins of Jorvik, recreated to be like the town on that time including all the smells. Aggleton and Waskett (1999) found that recreating these smells helped people to recall the details of their trip to the museum more accurately, even after several years. Questions 1. Explain this finding in terms of cues. 2. Can you think of a way in which the findings like these could be used to help elderly people suffering from poor memory? 52

53 Factors Affecting Eyewitness Testimony Misleading Information and Anxiety 53

54 Factors Affecting Eyewitness Testimony Misleading Information I do solemnly, sincerely and truly declare and affirm that the evidence I shall give shall be the truth, the whole truth and nothing but the truth Context The scene above is familiar to anyone who has ever watched TV. It is a cornerstone of our legal system that without evidence, a person cannot be found guilty of a crime. This is why all witnesses must swear in court to only tell the truth. However, what happens if the eyewitness believes that they are telling the truth, but really they are providing testimony which is not 100% accurate? When a witness to a crime has nothing but their own memory to rely on, can we be sure that their testimony is a real account of what actually happened? What is eyewitness testimony (EWT)? Eyewitness testimony is a legal term, referring to the use of eyewitnesses to give evidence in court. What does the Innocence Project suggest about the importance of (EWT)? An organisation which works to clear the names of wrongly convicted people They claim that eyewitness misidentification is the greatest single cause of wrongful convictions in the USA, convictions that were later overturned by DNA evidence. Eyewitness Testimony You may be surprised how difficult it is to remember what a 10p looks like without having one in front of you. There will be a number of inaccuracies. We do not need to have 100% recall for all information we use everyday. For example we only need to know the shape of coins and notes to be able to use them correctly. Task In pairs and without looking anything up, try to do the following 2 tasks. 1. Draw a picture of a 10p coin, front and back. 2. Write down the person on the front of a 5 note. Write down the words written at the top of the front of the note of any denomination (i.e. 5, 10, 20, 50). 54

55 10p Coin Bank Note Watch the clip carefully. Half way through I will stop the video and you must write down all the changes you saw in the clip. Over all there are 21. You have 3 minutes! Eyewitness memory goes through three stages 1)The witness encodes info into LTM (the event and the person involved), may be partial as the event occurs quickly, at night and accompanied by rapid, violent, complex action. 2)Witness retains info for a time. Memories may be lost or modified during retention, other activities may interfere with the memory itself. 3)Witness retrieves memory from storage. What happens next is there may be a presence or absence of info that may affect the accuracy of the memory. 55

56 Factors affecting EWT: The main factors affecting accuracy of memory can be placed into two categories: Witness factors: age, race, gender and individual response to anxiety or stress. Event factors: duration of event and level of violence witnessed. We will be looking at the effect of misleading information, post event discussion and anxiety. Misleading Information Leading Questions One reason why the accuracy of EWT is often very poor could be because of leading questions used by the police after the event. Information received after an event can have a retroactive interfering effect on our recollection; in other words, retroactive interference occurs when later learning interferes with previous learning; i.e., A leading question is a question that either by it s form or content, suggests to the wittness what answer is desired, or leads him to the desired answer. incoming information gets integrated and confused with our existing knowledge. Previous research has suggested that the mind does not work like a camera. Our mind does not just take a picture of what it sees, and then reproduces this memory accurately. Our memories can easily be altered by other information. Elizabeth Loftus Key Study- Loftus and Palmer (1974) Reconstruction of automobile destruction: an example of the interaction between language and memory Aims Loftus and Palmer s experiment was actually two experiments. They wanted to investigate in general how accurate or inaccurate memory was. Specifically they wanted to see the effect of upon estimates of. Experiment 1 To see if the speed estimates given by participants upon watching a video of a car crash would be influenced by the wording of the question asked. They wanted to see if participants who were asked a question with the word hit in it would give a different estimate of speed than those who were asked the same question but with the word smashed 56

57 Experiment 2 Loftus and Palmer also wanted to see if the leading questions just changed the responses given to the questions, or whether the participant s memories had actually altered as a result of the leading questions. 2. PROCEDURES As stated previously, Loftus and Palmer carried out two experiments. You need to know detailed procedures for both of them, as well as participant numbers. Use the text on the right (taken from the original article), complete the summary table for experiment 1 and 2 on the next page. Experiment 1 Number and make-up of participants Research method used Experimental design Laboratory experiment Independent measures Independent variable Dependant variable Put the steps of the procedure of experiment 1 into the correct order. After each film, each participant was The participants were 45 students given a questionnaire. The critical question was about the speed of the cars Each participant watched 7 films depicting a traffic accident. Each film lasted from 5-30 seconds, and were presented in a different order to each group. The blank was filled with one of the following words: hit, smashed, collided, bumped or contacted The second part of the questionnaire was a series of specific questions about the film All participants were asked the question How fast were the cars going when they each other? The first item on the questionnaire was asking the students to simply give an account of what they had seen. 57

58 Experiment 2 Number and make-up of participants Research method used Experimental design Independent variable Dependant variable Laboratory experiment Independent measures Summarise the experiment in bullet points 58

59 3. FINDINGS AND CONCLUSIONS Experiment 1 Average speed given for the different verbs used Verb used in critical question Smashed 40.5 Collided 39.3 Bumped 38.1 Hit 34.0 Contacted 31.8 Mean speed estimate (mph) Summarise the results of table/graph Conclusions Explain how the results above support the theory of leading questions 59

60 Experiment 2 Findings No of ppts who claimed to see broken glass Condition Yes No Hit 7 43 Smashed Control 6 44 Summarise the results of table/graph Conclusions what do the results suggest about misleading post-event information? 60

61 Misleading Information Post Event Discussion When co-witnesses to a crime discuss it with one another (post event discussion) their eyewitness testimonies may become contaminated. This is because they combine (mis)information from other witnesses with their own memories. Research has demonstrated how this has happened. Gabbert (2003) Summarise the study procedure and findings using p58 Evaluation Real-life applications A great strength of all research into misleading information is that it has hugely important practical uses in the real world, where the consequence of inaccurate EWT can be very serious indeed. Eg. Loftus (1975) believes that leading questions can have such a distorting effect on memory that police officers need to be very careful how they phrase their questions when interviewing eyewitnesses. Research into EWT is one area in which psychologists believe they can make an important positive difference to the lives of real people, for instance by improving the way the legal system works and by appearing in court trials as expert witnesses. 61

62 The tasks are artificial In regards to Loftus and Palmer s study, the participants all watched film clips of car accidents. This is a very different experience from witnessing a real car accident, mainly because such clips lack the stress of a real accident. There is some evidence to suggest that emotions can have an influence on memory. Is this a strength or weakeness? Why? Individual differences Anastasi & Rhodes (2006) used individuals from three age groups. They had to rate 24 individuals (from different age groups) for attractiveness. Later they were presented with 48 photos: 24 they had seen previously, and 24 distractors. Young Participants Middle Aged Participants Older Participants Young Photos Middle Aged Photos Older Photos What do these results imply about age of the participant and age of the target? 62

63 Apparent age effects may be due to the fact that people do best when asked to identify people of their own age group. Perhaps this is because we have more contact with people who are a similar age to us. The lesser experience we have, the greater the own age bias. When we encounter people of our own age group more regularly we become better at processing those faces and therefore have better memory for them. Research studies often use younger people as the target to identify - what issues could this raise? 63

64 Match the study to the conclusion 1: Loftus and Zanni (1975) Showed participants a film of a car accident. Some participants were asked Did you see a broken headlight? whereas others were asked Did you see the broken headlight? 7% of those asked about a broken headlight reported seeing one, whereas 17% asked about the headlight reported one. (There was not one in the video) 2: Loftus (1979) Showed participants a series of pictures of a man stealing a red wallet from a woman s bag. 98% of participants were able to identify the colour correctly. Later, Loftus used leading questions to try and alter the participants recall. However, they persisted in describing the purse as red. 3: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 done it. 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. 4:Yullie and Cutshall (1986) Interviewed 13 people who had witnessed an armed robbery in Canada four months after. They included two misleading questions. They found that the participants were not led by the leading questions, and the accounts that they gave were very similar to those in their initial witness statements 5: Loftus and Pickrell (1995) Interviewed participants about events in childhood, planting a false memory of being lost in a mall as a child (an event that never happened). 20% of the participants came to believe that this event had actually happened, and some even clung to the memory after being debriefed. 6: Braun et al (2002) Participants who had visited Disneyland as a child were told that they would be evaluating advertisements for it. Group one were given an ad with no characters on it, group two were given the same ad with a cardboard Bugs Bunny in the corner of the room; group three were given an ad that had bugs bunny on it, and the group four got the Bugs Bunny ad and the cardboard Bugs Bunny. When asked later about having met Bugs Bunny as a child, 30% of group 2 and 40% of group 4 recalled meeting him. (Bugs Bunny is not Disney, so this was a false memory) This research contradicts Loftus and Palmer, as it suggests that in some circumstances, leading questions have a limited effect on memory. It may be that the information to be remembered in this study was less subjective than estimating speed. This study develops the research into EWT. Whereas Loftus and Palmer investigated the effect of leading questions in altering memories of real events, this research suggests that leading questions can even plan memories that were never there. It develops the theory that verbal information can alter memory. A criticism of Loftus and Palmer was that the participants knew that they were in a study, and so their behaviour may have been unnatural. This study gets around this issue by demonstrating that recall in real life, when participants do not know that they will be asked to recall is still very poor. This study has the advantage of letting us see the effect of leading questions on real life eyewitnesses. It suggests that the results of Loftus and Palmer only apply in a laboratory setting, not in real life cases. It supports the argument that Loftus and Palmer s research lacks ecological validity. A criticism of Loftus and Palmer s experiment is that judging speed is complex, and therefore the participants more prone to being led by leading questions. This research however demonstrates that leading questions can actually cause participants to remember something that was not there. This supports Loftus and Palmer, as it provides more evidence that leading questions can alter the response given. This research build upon the results of Loftus and Palmer, as it suggests that misinformation does not need to be verbal for it to have an effect on recall. False memories can be established by non verbal/visual information. Use two colours to highlight research that supports or contradicts Loftus and Palmer s research. 64

65 Apply It Seema Clifasefi et al (2013) attempted to use leading questions to implant a memory of an event that never happened (called a false memory). They did this by giving their participants a document that claimed to be a personalised food and drink profile. This was supposedly put together by a powerful computer software based on the participant s earlier responses to a questionnaire. For one group, their profiles included false information that they had once, under the age of 16, drunk so much alcohol that they were sick. Later the participants completed a memory test in which a leading question asked when they had become sick from drinking too much alcohol. The researchers found that a significant number of participants recalled being sick due to drinking too much alcohol before they were 16. But even more surprisingly, a proportion of these participants also claimed that they now disliked certain alcoholic drinks because of this (non-existent) experience Question Using your knowledge of misleading information, explain the findings of this study. 65

66 Factors That Influence The Accuracy Of EWT Anxiety Anxiety After looking at the pictures what were your eyes drawn to? How might this make you feel? How might this affect how your performance as an eyewitness? What does being Anxious feel like.? 66

67 Anxiety is an unpleasant emotional state where we fear that something bad is about to happen. People often become anxious when they are in stressful situations. This anxiety tends to be accompanied with physiological arousal (increased heart rate, shallow breathing). Due to this, much of the research in eye witness testimony is now focused on the effects of arousal. Using the pictures in front of you. 1)Rank them from most stressful to least stressful. Give each of them a score from 1-10 (1 being least stressful, 10 being the one that would cause the most anxiety!) 2)Rank them in terms of how much you might remember after witnessing each event. Give each of them a score from 1-10 (1 being the one you d remember least about, 10 being the one that you d remember most about.) Picture Stress Rating Exam Room Car Crash Robbery Football Match Fire Funfair Ride Charity Event Kitten Riot Knife Attack Picture Likely to Remember Exam Room Car Crash Robbery Football Match Fire Funfair Ride Charity Event Kitten Riot Knife Attack 67

68 Plot your values on a graph with stress/anxiety on the X axis, and amount you d correctly remember on the Y axis. 68

69 Once you ve plotted all your values, join them up. What pattern do you get? What does this suggest about the effect of stress on recall? What does the research say? Loftus & Burns (1982) Participants shown a violent version of a crime where a boy is shot in the face. Participants had significantly impaired recall for events running up to the violent incident. Does this suggest that Anxiety has a positive or negative effect on eyewitness testimony? Christianson & Hubinette (1993) Questioned 58 real victims of a bank robbery. They found that those who had actually been threatened were more accurate in their recall, compared to those who were onlookers. This continued to be true 15 months later. Does this suggest that Anxiety has a positive or negative effect on eyewitness testimony? 69

70 Summarise the Johnson and Scott (1976) study of the Weapon Focus Effect. Include the procedures, results and conclusion. Summarise the Yuille and Cutshall (1986) study. Include the procedures, results and conclusion. 70

71 Evaluation (AO3) How can we explain these contrasting findings? Deffenbacher suggests that this apparent contradiction in research findings could be best explained with reference to the Yerkes-Dodson law which states that performance improves with increases of arousal up to some optimum point and then declines with further increases. The Yerkes-Dodson Law Task: How would this explain the conflicting research? 71

72 Evaluation of Research Issues with the Weapon Focus Effect It has been suggested that the Johnson and Scott (1976) study actually is testing surprise rather than anxiety. The reason why participants may focus on the weapon may be because they are surprised at what they see rather than because they are scared. Pickel (1998) Conducted an experiment using scissors, a handgun, a wallet or raw chicken as the handheld items in a hairdressing salon video. It would be assumed that the scissors would create low anxiety and low unusualness. They found that eyewitness accuracy was poorer in the high unusualness conditions the raw chicken and the handgun. What does this suggest? Issues with Field study research Researchers usually interview real-life eyewitnesses sometime after the event. In this time all sorts of things could have happened that the researcher has absolutely no control over. What things can you think of that could happen after the event? What are these called? Ethics Creating anxiety in participants can be very risky. It is potentially unethical because of the psychological harm they subjected to purely for research purposes. This is why real-life studies are so beneficial - psychologists interview people who have already witnessed a reallife event, so there is no need to create it. This issue doesn t challenge findings from lab studies like Johnson and Scott but it does question the need for it. One reason could be to compare findings with less controlled field studies and the benefits of this research may outweigh the issues. 72

73 The Cognitive Interview 73

74 The Cognitive Interview Read the interview scripts and consider the following questions. What is good about the interview? What is bad about the interview? Which one do you think this is a cognitive interview and why? 74

75 The Cognitive Interview This is a police technique for interviewing witnesses to a crime, which encourages them to recreate the original context in order to increase the accessibility of stored information. Why is it important? For improving effectiveness of questioning witnesses in police interviews Apply findings of psychological findings to this area Fisher and Geiselman (1992) Reviewed memory literature and related this to the way interviews were carried out by the police in real life. They found, for example, that people remember things better if they are provided with retrieval cues. Fisher and Geiselman developed an interviewing technique, the cognitive interview (CI), which is based on proven psychological principles concerning effective memory recall. The original interview technique could be characterised by four distinct components. 75