What is Memory?

“Memory is the process of maintaining information over time.” (Matlin, 2005)

“Memory is the means by which we draw on our past experiences in order to use this information

in the present.” (Sternberg, 1999).

Memory is the cognitive process which encodes, stores and retrieves information.

Encoding – literally means to put something into a code. In memory, information can be coded in different forms, as: visual, auditory, taste, smell etc.

Storage – once information is recorded in a code, it is then stored in memory.

Retrieval – for memory to function effectively it is necessary that the stored information can be recovered. Retrieval involves recognition, recall and reconstruction.

Many of the prevalent theories of memory are based on the assumption that there are 3 kinds of memory: These are:

1. Sensory memory – this storage system retains information in its ‘raw’ form fractions of a second after the physical stimulus has gone. Baddeley (1988) suggested that one function of this kind of storage is to retain information for long enough to allow for the consolidation of information from minute eye movements. This allows us to integrate the information rather than see life as a series of ‘snap shots’.

2. Short-term memory – a limited amount of processing takes place here. Short term memory has a very limited capacity (7 items +/- 2) and short duration (max. 30 seconds), unless the information in it is maintained through rehearsal.

3. Long-term memory – this is a relatively permanent store which has unlimited capacity and duration. Information is passed to long-term memory from short-term memory after rehearsal. Some different kinds of long-term memory are:

episodic (memory for past events)

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semantic (memory for details or factual information) procedural (memory for how to do things (skills).

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Difference between short-term & long-term

memory

Encoding

Duration

Capacity

Tasks:

1. What is memory?2. Explain the 3 types of memory.3. For each type of memory explained in question 2, provide an example of the type of

data that would be remembered.

1. Short-term Memory (STM)

Some researchers (e.g. Atkinson and Shiffrin, 1968) see short-term memory simply as a temporary static repository for information received from our senses.

Others (e.g. Baddeley 1986) use the term ‘working memory’ suggesting that it is a dynamic and flexible process rather than a ‘storage box’.

Encoding

Information arrives in sensory memory in its original form, i.e. in the mode it was first perceived e.g. sound (acoustic), sight (visual), etc. However, we are unaware of the code used, since memory processes are unconscious.

Conrad (1964) provides information on coding in STM.

Conrad (1964) Aim: to find out whether acoustic coding is used in short-term memory, even when initial information is presented visually. Method: 387 participants were shown sequences of 6 letters on a screen and told to write them down as they appeared.The words appeared faster than they could be written down and therefore memory had to be used. Letters that were used were: B, C, F, M, N, P, S, T, V, & X. Results: Where errors in recall were made Conrad found that participants substituted letters which sounded similar eg B for V or X for S etc. Conclusion: This suggests that STM processes visual information acoustically.

Baddeley (1986) found that words which sounded similar were more difficult to recall, than dissimilar sounding words. Performance was only slightly affected when words were presented that had similar meaning. Baddeley’s research supports that of Conrad; that short-term memory relies more on the sound of words rather than on their meaning. (See Encoding LTM). Other researchers (e.g. Brandimonte et al 1992) have found that acoustic coding is the preferred method of encoding in short-term memory, but where this is not possible, visual coding will be used.

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Capacity

The ‘memory span’ technique was devised by Jacobs (1887). This technique was the first systematic study of the capacity of short-term memory. Jacobs reported that the memory span for digits or letters was between 5 and 9 items and that short-term memory span increased with age (he saw this as either being due to increased brain capacity or to the use of memory techniques).

“Most people have a digit span of seven, plus or minus two” (Miller, 1956)

Later research by Miller (1956) coined the term ‘magic number 7’. Miller claimed that capacity of 7+/-2 was true not only for a list of digits, letters, or words but also for larger ‘chunks’ of information.

Chunks are integrated pieces, or units of information. What constitutes a ‘chunk’ depends on personal experience. ‘Chunking’ has been shown to increase the capacity of STM but it may reduce its accuracy.

Example 1: Mobile telephone numbers are longer than 9 numbers.In order to remember a number, you ‘chunk’ it.

“What’s the number again?”“555- 367- 55-22-22”

Example 2:If I asked you to remember a series of letters you would find it difficult. “HFBEYWEBF”

But you would have no problem remembering this series of letters. “XYLOPHONE”

And that is because with that series of letters, you only have to remember one thing; what a Xylophone is. You have chunked the information into one memorable chunk.

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Tasks:

1. How is information encoded?2. What did Conrad (1964) say about encoding in STM?3. What is the capacity of STM? Provide support for your answer using research and real-

life examples.

The Recency and Primacy Effects

The recency effect can be measured using free recall.

Participants are shown a list of words or syllables, and are asked to recall as many as they can in any order. The recency effect is evident when the last few items in a list are remembered better than those from the middle of the list. The words from the end of the list are recalled from STM.

Galnzer and Cunitz (1966) found that when an interference task was given between the end of list and the start of recall, the recency effect was virtually eliminated. The interference task had little effect on other aspects of recall.

They also found that participants recalled the first few items from the list much better than those from the middle of the list. This became known as the primacy effect – the words at the start of the list have been rehearsed more than those from the middle of the list and have a better chance of being recalled.

Evidence of the recency effect however, suggests that the capacity of short-term memory is only two or three items (since that is usually how many items from the end of the list are recalled), however the memory span technique suggests a capacity of about seven items. One reason for this discrepancy is that when carrying out a span task, participants will rehearse as many items as possible, whereas those asked to learn a list for free recall only have the opportunity to rehearse a few items at a time.

The important point made by both measures is that the capacity of short-term memory is limited.

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Tasks:

1. What is the recency effect?2. What is the primacy effect?3. Give examples of real life situations where you have experienced

a. The recency effectb. The primacy effect

Duration

The first attempts to measure the duration of short-term memory, used an experimental technique called the Brown-Peterson technique .

Peterson and Peterson (1959) Aim: To test how long short-term memory lasts when rehearsal is prevented. Method: Participants were briefly shown a consonant trigram (ie. 3 letters such as MWG or CGX). Participants were asked to count backwards in 3s from a 3-figure number eg 422 to stop them rehearsing the letters.

After intervals of 3, 6, 9, 12, 15 or 18 seconds, participants were asked to recall the original trigram.

The procedure was repeated several times using different trigrams. Results: Participants were able to recall 80% of trigrams after a 3-second interval. As time intervals got longer, fewer trigrams were recalled. After 18 seconds, less than 10% of the trigrams were recalled correctly. Conclusion(s): If rehearsal is prevented, information is quickly lost from short-term memory. Decay is the cause of forgetting from short-term memory

The key point to remember from the Brown-Peterson technique is that items are lost from short-term memory, only when rehearsal is prevented.

Because of the limited capacity of short-term memory, new items can only take the place of lost items if existing items move on. Repetition is used to reinsert information into the short-term memory and thus strengthening the memory.

The duration of short-term memory is less than 30 seconds, if rehearsal is prevented.

Three factors which can affect duration:

Rehearsal - when rehearsal is prevented, information is lost from short-term memory. Effort - Sebrechts et al (1989) showed that information is lost from the short-term

memory in a matter of seconds if no effort is not made to retain it. Capacity - the important factor is not the number of individual items to be recalled, but

the number of chunks of information.2. Long-term Memory (LTM)

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Tasks:1. Explain what was done in class to measure the duration of STM.2. Do these findings support the findings of Peterson & Peterson (1959)?3. According to the Brown-Peterson technique, why are items lost from STM?4. What 3 factors affect the duration of STM?

Long-term memory is not a passive store of information; rather it is a dynamic process that continually modifies stored information in the light of new information (adaptation). It has a capacity for vast quantities of information, which can be stored for indefinite periods of time.

Long-term memory is therefore larger, and more complex than short-term memory.

Encoding

Baddeley (1966) states that long-term memory uses mainly semantic coding (i.e. based on the meaning of information) together with both visual and acoustic coding.

Baddeley (1966) Aim: To study the effects of acoustic and semantic coding on short-term and long-term

memory. Method: Participants were given a list of words which were semantically similar (e.g. messy/ dirty/ untidy/unkempt).

They were also given a list of words that were acoustically similar (heat/sweet/meat).Recall was tested immediately, and then again after some time had passed. Results: Immediate recall produced confusion between acoustically similar words, while there

was found to be little problem with words of similar meaning. On later testing, the words with similar meaning caused problems.

Conclusion: The confusion over words with similar meaning after a period of time is evidence to

support the theory that long-term memory mainly uses a semantic code. The confusion on lists of words with similar sounds is evidence in support of the

acoustic coding of short-term memory.

Capacity

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It is very difficult to give an exact capacity for long-term memory.

“No human yet exists who can use all the potential of his/her brain. This is why we don’t accept any estimates of the limits of the human brain.” (Anokhin, 1973)

Anokhin estimated that the human brain had a 1 followed by 10.5 million kilometres of zeros of neural connections.

“[Within the human brain] neurons combine so that each one helps with many memories at a time, exponentially increasing the brain’s memory storage capacity to something around 2.5 petabytes [1 petabyte ≈ 1,000 terabytes].

For comparison, if your brain worked like a digital video recorder in a television, 2.5 petabytes would be enough to hold three million hours of TV shows. You would have to leave the TV running continuously for more than 300 years to use up all that storage.” (Reber, 2010).

It would seem logical to assume that there would be some physical limit (in terms of available brain cells) to the capacity of long-term memory however, to date no quantifiable limit has ever been established.

Duration

Bahrick, Bahrick and Wittinger, 1975 found that even after 34 years, people could still name 90% of the photographs of classmates from their high-school yearbook.

Bahrick et al (1975)

Aim: To study what they called very long term memory (VLTM).

Method: Nearly 400 participants aged 17 – 74 were tested. There were various tests including:

A free recall test, where participants tried to remember names of people in a graduate class. A photo recognition test, consisting of 50 pictures. A name recognition test for ex-school friends.

Results: Participants who were tested within 15 years of graduation were about 90% accurate in

identifying names and faces. After 48 years they were accurate 80% for verbal and 70% visual. Free recall was worse. After 15 years it was 60% and after 48 years it was 30% accurate.

Conclusion: People can retain accurate memories for several decades.

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This provided a good method of assessing the accuracy of very long-term memories and at that time was the clearest indication that people can retain accurate memories for several decades.

Three factors which affect the duration of long-term memory:

Childhood amnesia: very young children cannot organise and integrate memories in such a fashion as to facilitate later recall.

Learning: good initial learning facilitates later recall from long-term memory. If a person does not have a good initial experience encoding and storing their recall will suffer later (Bahrick & Hall, 1991).

Recognition: memories from the distant past are more likely to be recalled if there is some form of recognition involved. Bahrick et al (1975) found that recall of old classmates could be improved if people were provided with clues, for example; if this John or Simon?

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Tasks:

1. Using the following headings, make notes about LTM. You can present your information in any format that you want.

a. Encodingb. Capacityc. Duration

Varieties of Long-term Memory

Tulving (1972) distinguished between the types of long-term memory:

Episodic memory is the storage of information about events and the relationships between them.

I handed in my assessment late and I lost 10% of my marks I drank half a bottle of Tequila and don’t remember most on the next day I left the window of the car open and got my CD player stolen.

All of these episodes describe personal experience.

Semantic memory is memory for more permanent items of knowledge. It contains information about our knowledge of the world e.g.

2 + 2 = 4 Paris is the capital of France Kiwi cannot fly

These are based on: concepts, understanding. The information is more useful than episodic. Therefore you are less likely to forget it!

Tulving has defined semantic memory as:

‘A mental thesaurus, organised knowledge a person possesses about words and other verbal symbols, their meanings and referents, about relations among them, and about rules, formulas and algorithms for the manipulation of these symbols, concepts and relations. Semantic memory does not register perceptible properties of inputs, but rather cognitive referents of input signals’ (Tulving, 1972)

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Evidence:Tulving (1989) has also shown that different parts of the brain are active during retrieval of episodic and semantic memories. When using episodic memory of the frontal cortex is active, whereas semantic memory was associated with activation in posterior regions. This is measured using blood-flow patterns in the brain during different tasks.

However, Baddeley, 1984 and McKoon et al (1986) argue that different blood-flow patterns may be evident when carrying out any two differing tasks.

Procedural memoryProcedural memory is a part of the long-term memory that is responsible for knowing how to do things, also known as motor skills. As the name implies, procedural memory stores information on how to perform certain procedures, such as walking, talking and riding a bike. Delving into something in your procedural memory does not involve conscious thought.Procedural memory is a subset of implicit memory, sometimes referred to as unconscious memory or automatic memory. Implicit memory uses past experiences to remember things without thinking about them. It differs from declarative memory, or explicit memory, which consists of facts and events that can be explicitly stored and consciously recalled or "declared."

Musicians and professional athletes are said to excel, in part, because of their superior ability to form procedural memories. Procedural memory is also important in language development, as it allows a person to talk without having to give much thought to proper grammar etc.

Some examples of tasks dependent upon procedural memory:

Playing piano Skiing Ice skating Playing baseball Swimming Driving a car Riding a bike Climbing stair

Evidence: Amnesic patients show little to no Procedural Memory decline. Research examples include Clive Wearing and Patient HM. (See Biological approach). They can even learn NEW skills! For example; Clive Wearing was able to learn to play a new piece of music on the piano, but never be able to remember ever learning it. This demonstrates they must be different types of Memory involving different parts of the brain.

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Explain, with evidence and examples, the following types of memory:

a) Episodic memoryb) Semantic memoryc) Procedural memory

3. Why do we forget things?

The term forgetting can have several meanings:

The information is not available because it was never stored. The information is not accessible – also known as tip of the tongue phenomenon Interference has occurred and caused confusion Actions occur through habit/automatic responses rather than through accessing appropriate

information. This can be seen as absentmindedness.

Generally, forgetting is seen as the inability to recall information that has been stored.

Reasons for Forgetting in Short-term Memory

Trace Decay Information is forgotten because of the passage of time. Peterson and Peterson, (1959) found that the duration of short-term memory was approximately 18 seconds, after which they time the memory disappeared via trace decay.

As a result of excitation in nerve cells, a brief memory trace is laid down (Hebb 1949). At this stage the trace is fragile and likely to be lost. However, with repeated neural activity (via rehearsal), a permanent structural change can occur and the memory is transferred to the long-term memory where decay is unlikely.

Displacement We saw earlier that short-term memory has a limited capacity (7+/-2). As more items are introduced into short-term memory, it is inevitable that some items ‘drop out’, as there is not enough space for them i.e. old items are displaced by new ones.

Evidence for this comes from the Brown-Peterson technique. Where we saw that the last few words on a list were displaced from short-term memory by the counting task.

Diversion of Attention If attention is not focused on the information to be retained and is diverted towards something else then it is more likely to be forgotten.

Brain DamageDamage to the brain causes a variety of effects on performance. Warrington and Shallice’s (1972) study of KF found that his short-term memory forgetting of auditory letters and digits was much greater than his forgetting of visual stimuli, suggesting that the short-term memory is not just a single store, but consists of a number of different stores. (See WMM)

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Reasons for Forgetting in Long-term Memory

Trace Decay Lack of use can cause decay of long-term memory e.g. of knowledge and/or skills. “Use it or lose it!”

E.G: You can’t remember anything you learned in S3 French because you haven’t taken it since.

Retroactive Interference This is when new information interferes with the ability to recall old information. This area was widely studied in the 1960s but has received little attention since.

E.G: being unable to remember your old phone number, because the Information has been replaced with your new number.

Proactive Interference This is the reverse of retroactive interference and occurs when old information interferes with the recall of new information.

Example: when you try to put your number new PIN into your phone the first few times and keep putting in your old one every time.

In both cases of interference, the more similar the interference material is to the stimulus material, the greater the interference and the more likely it is that information will be forgotten.

Cue-dependent forgetting This refers to two related phenomena: context-dependent forgetting and state-dependent forgetting.

1. Context-dependent forgetting – it is easier to remember information when required to do so in the same environmental context as it was first learned (Abernathy, 1940). Retrieval cues act as a trigger for the original memory.

Example: You forget a lot of French vocab until you are back in the Modern languages classroom.

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Godden and Baddeley (1975)

Aim: To investigate the effects of context cues on recall. To see whether words learned in the same environment they are recalled in are recalled better than in a different environment to learning. To see if this applies in a natural setting, words learned and recalled either on land or under water.

Method: 18 diving club pp’s took part in a repeated measures design consisting of 4 conditions – learning words on land and recalling on land, learning words on land, recalling under water; learning under water recalling under water, learning under water, recall on land. In the underwater condition this was at 20ft below surface.

They had to learn 38 unrelated words which they heard twice during the learning stage. This was played through a diving communication device and the words were presented in blocks, with a 4 second interval in between to ensure the noise of the breathing apparatus did not affect hearing. As a distraction they then had to listen to and write down 15 numbers. There were 24 hours between conditions and the study conducted over 4 days. PP’s were tested in pairs.

Results: Around 50% better recall when learning and recall are the same, 40% more words were

forgotten when the condition changed. Recall for learning on land and recall on land was 13.5 compared to 8.6 when they learned

the words on land and had to recall under water.

Conclusion: environmental cues do improve recall and supports cue dependent theory

2. State-dependent forgetting – it is easier to remember information when you are in the same physical and emotional state as you were when you first learned it (Goodwin et al, 1969).

Example: you can’t remember what you did in a fit of rage, but the next time you’re angry, you remember.

State-dependent learning has been shown in a number of ‘altered states of consciousness’ including:

depressants (Goodwin et al, 1969, alcohol) emotional states (Weingartner, 1978, depression) hallucinogenics (Eich et al, 1975, marijuana) hypnosis (Bower et al, 1978) stages of sleep (Bonnet, 1983) stimulants (Bustamante et al, 1970, amphetamines)

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Brain Damage

Any change or damage to the brain which may be a result of closed head injury, brain surgery, stroke or electro-convulsive therapy (ECT) may suffer from retrograde amnesia – this is a loss of memory for any events which occurred prior to injury/treatment.

Korsakov syndrome, is the result of advanced alcoholism causes anterograde amnesia – this is the loss of memory for new information. (See Biological approach to memory)

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Tasks:

1. What does it mean to “forget”?2. Why do we forget information from our STM? [you should give two explanations]3. What evidence is there to support these explanations of forgetting?4. Why do we forget information from our LTM? [you should give two explanations].5. What evidence is there to support these explanations of forgetting?

4. Psychoanalytical Approach to Memory (Repression)

The psychoanalytic approach in psychology has a heavy emphasis on the effect of emotional factors on behaviour. Freud (1915) proposed that we are motivated to forget events by the desire to avoid displeasure. Therefore embarrassing, unpleasant and anxiety provoking experiences are repressed i.e. pushed down into the unconscious.

Repression is a defence mechanism, which is initiated by the ego. It is an unconscious process and blocks the conscious recall of memories.

The psychoanalytic approach utilises case studies as a research method. These case studies provide examples of repression. Freud reported the case of a man who kept forgetting the line ‘With a white sheet’.

Free association (technique used by Freud to access the unconscious) revealed that the term ‘white sheet’ was associated with the sheet placed over a corpse. The man’s friend had recently died from a heart attack and the white sheet was associated with death. The man was overweight, he feared his own death since his grandfather had died of a heart attack.

Evidence: (?)

Attempts have been made to demonstrate repression under laboratory conditions.

Levinger and Clark (1961)

Levinger and Clark compared the retrieval of associations to emotionally charged words with the retrieval of associations to neutral words.

Example of emotional words; hatred, evil, hurt…Example of neutral words; service, pathway, table…

They found: Participants took longer to give free associations to negatively charged words than to neutral words. Participants found it more difficult to recall the associations they had given for the negatively

charged words compared with the neutral words. The negatively charged words produced higher galvanic skin responses than the neutral words.

Levinger and Clark concluded that it was repression that led to the emotionally negatively charged words being more difficult to recall. This supports Freud’s theory that repression causes forgetting.

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5. Biological Approach to Memory

Brain structures involved in Memory formation.

The hippocampus in the medial temporal lobe plays a very important role in learning and memory.

Situated in the medial temporal lobe, the hippocampus is believed to be directly responsible for the consolidation of short term memory and long term memory. In particular, the hippocampus is responsible for the formation of new memories related to experiences events, also known as autobiographical or episodic memories.

Declarative memories, those that can be verbalized more explicitly than episodic memories, are formed but not stored in the hippocampus. These memories as well as past events are believed to be stored in the frontal and temporal lobes.

There are two hippocampi in the brain, one in the left hemisphere and the other one on the right. When one of these hippocampi are damaged and the other one is left intact, the person can still experience almost normal memory functioning. However, severe damage or removal of both hippocampi as in the case of Patient H.M. results to anterograde amnesia. (See Evidence)

A process called long-term potentiation (LTP) occurs in the hippocampus. LTP refers to the increase in neural responsivity. Recent research studies proved that LTP is involved in spatial learning.

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In layman’s terms; imagine if you will your brain is a dense forest of neurons. All tangled up. When you make a connection you break through those dense branches, and clear a pathway. The more times you walk down that pathway through the forest, the clearer the pathway becomes, the easier it is to walk down it. This is why things become easier to remember the more that you practice them. There is evidence to suggest that sleep plays a huge role in strengthening these pathways.

Alcohol and Memory

Alcohol, and the effects of alcohol on memory and general cognitive functioning, has been the subject of much research over the years.

Alcohol acts as a general central nervous system depressant, but it affects some areas of the brain more than others. Specifically, it leads to distraction and inattention and significantly inhibits neuronal activity in the hippocampus, which impairs memory encoding since the hippocampus plays an important role in the formation of new declarative memories. Because procedural memory functions more or less automatically, retrieval of procedural memory (“remembering how”) is not as severely impaired by alcohol as retrieval of declarative memory (“remembering what”).

This is why no matter how much they drink, some people still have the ability to walk home! They may not have been aware of it, but their cerebellum knew the way home. This is because “walking home” is procedural (you don’t consciously think, “Where do I live?” You just walk home!)

Alcohol particularly impairs the encoding of episodic memory (that part of declarative memory that relates to our personal experiences and specific events in time), especially for certain types of recall, such as cued recall, the recognition of completed word fragments and free recall.

A "blackout" is an example of a difficulty in the encoding of episodic memories due to high doses of alcohol. It is caused by a rapid increase in blood alcohol concentration, which in turn distorts the activity of neurons in the hippocampus, thus impairing person's ability to form new episodic memories. Alcohol also severely disrupts the encoding and storage process of new semantic memories (our memory of facts, meanings and acquired knowledge about the external world), although apparently not that of previously learned information.

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Task:

1. Collect a copy of the brain diagram from your teacher and label. You need to explain what each part of the brain is responsible for in relation to memory.

This means that when you wake up the next day and can’t remember what happened last night, it’s because actually your brain was never remembering it to begin with. You haven’t forgotten, you never started the process of remembering it in the first place!

Alcohol also impairs short-term (working) memory, although mainly by affecting certain mnemonic strategies and executive processes rather than by shrinking the basic holding capacity of working memory or by physically altering the structure of the those parts of the brain which are critical for working memory function. Although light to moderate drinking does not appear to impair long-term cognitive functioning significantly (and according to some studies, may actually decrease the risk of cognitive decline), heavy drinking and chronic alcoholism is associated with long-term impairment in sustained attention and working memory function, especially visual working memory.

Serious over-consumption of alcohol, especially in comparison with the intake of other foods, can cause a thiamine deficiency, leading to a much more serious form of amnesia known as Korsakoff’s syndrome.

Korsakoff syndrome causes problems learning new information, inability to remember recent events and long-term memory gaps. Memory problems may be strikingly severe while other thinking and social skills are relatively unaffected. For example, individuals may seem able to carry on a coherent conversation, but moments later be unable to recall that the conversation took place or to whom they spoke. Those with Korsakoff syndrome may "confabulate," or make up, information they can't remember. They are not "lying" but may

actually believe their invented explanations. Scientists don't yet understand why Korsakoff syndrome may cause confabulation.

Available data suggest that about 25 percent of those who develop Korsakoff syndrome eventually recover, about half improve but don't recover completely, and about 25 percent remain permanently unchanged.

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Tasks:

1. How does alcohol affect the brain?2. What impact does alcohol have in episodic memory?3. What is a “blackout” and what happens when you experience one?4. How does alcohol affect your short term memory?5. Explain how Korsakoff syndrome develops and the effect it has on memory.

Alzheimer’s

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive deterioration together with declining activities of daily living and neuropsychiatric symptoms or behavioural changes. It is the most common type of dementia.

The most striking early symptom is loss of short term memory (amnesia), which usually manifests as minor forgetfulness that becomes steadily more pronounced with illness progression, with relative preservation of older memories. As the disorder progresses, cognitive (intellectual) impairment extends to the domains of language (aphasia), skilled movements (apraxia), recognition (agnosia), and those functions (such as decision-making and planning) closely related to the frontal and temporal lobes of the brain as they become disconnected from the limbic system, reflecting extension of the underlying pathological process. These changes make up the essential human qualities, and thus AD is sometimes described as a disease where the victims suffer the loss of qualities that define human existence.

The cause of Alzheimer's disease is not known, but it is not a part of normal aging and thought to include both genetic and environmental factors. By causing both structural and chemical problems in the brain, AD appears to disconnect areas of the brain that normally work together. This shows that Biological memory involves the brains ability to make connections between neurons.

The most important risk factors are old age and a family history of dementia. In addition to age and family history, risk factors for AD may include longstanding high blood pressure, head trauma, and high levels of homocysteine (a body chemical that contributes to chronic illnesses such as heart disease, depression, and possibly AD). Because women usually live longer than men, they are more likely to develop AD.

Alzheimer’s and cures for the condition have formed plot points in such famous movies as Rise of the Planet of the Apes and Deep Blue Sea. In both of these films, scientists are trying to increase the connectivity in human brains, in an attempt to overcome the symptoms of Alzheimer’s.

Evidence of biological approach to memory

The case of Clive Wearing

Clive Wearing has one of the worst cases of amnesia in the world. A renowned conductor living in London, he was at the peak of his profession when he contracted a virus. This virus went on to destroy parts of his brain resulting in his memory loss. Clive’s descent into brain damage came frighteningly quickly; one weekend in March 1985 he returned home from work looking flushed and feverish. On Saturday his headaches started. By Tuesday he was no better and hadn’t slept. His temperature was 102°. By Wednesday he was very confused and couldn’t remember, his wife, Deborah’s name. His temperature was 104°. Doctors came and went and Deborah left him sleeping, but when

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she returned, Clive had disappeared. Over the next few hours Deborah rang hospitals and police stations across London. Clive eventually turned up. He had gone out fully dressed with his overcoat and a copy of The Times under his arm, hailed a cab and forgotten where he was going and forgotten where he lived. The cabbie dropped him at West Hampstead police station where they identified him from his Barclaycard.

Back home 2 doctors visited and concluded that Clive was suffering from a severe bout of flu that was doing the rounds in North London. His condition worsened and he was rushed to St. Mary’s Hospital where doctors realised that Clive’s brain was being attacked by the herpes simplex or cold sore virus. Very rarely this virus can cross the blood-brain barrier and cause encephalitis or inflammation of the brain.

The virus had destroyed his hippocampus; which psychologists now conclude is an area of the brain crucial for memory and learning leaving him with dense amnesia. His ability to play music has not been affected, but he is unaware of it. Having just played a beautiful piano piece he is asked about his music playing and he answers: “I’ve never heard a note since I’ve been ill. I don’t know what it’s like to play music”. The only person he recognises is wife Deborah.

He keeps a diary, and has done so for years. In it he records his, apparently, first moment of wakefulness and lucidity over and over and over again. As soon as he has recorded this momentous event he has forgotten it. Even with the diary in front of him, he has forgotten making the entry despite it facing him in black and white.

It is not only memories since the illness that he has lost. He has no memory of any event in his life, although he can remember key numbers and names from early childhood. He retains the power of speech and has a good vocabulary so word recall is not a problem. He can read and write but doesn’t remember doing either. He lives the same moment over and over again, with no awareness or recollection. In his own words “It is a living death”.

Further evidence

Patient H.M. underwent surgical removal of the medial temporal lobes. This resulted to anterograde amnesia (difficulty of forming new memories) and neologism (forming and/or using new words). However, procedural memories, semantic memories, speech, reading and writing were all left unaffected. This suggests that the hippocampus is directly involved in the formation of episodic memories, but forms not part of the formation of procedural memories.

Taxi drivers have been shown to have a larger than average hippocampus, because of their job requiring them to remember huge amounts of special data; how to get from A to B as fast as possible. (Maguire et al, 2000)

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Stress has been shown to have long term lasting effects on the size of the hippocampus. This explains why when you are particularly stressed, you have difficultly remembering anything. McEwen & Sapolsky, 1995).

Through use of imaging technology, a study found that there are individual differences in how alcohol impacts memory. Alcohol intoxication reduces activity in the hippocampus region of the brain, specifically involved in 'multitasking’. Alcohol appears to affect a person's ability to multitask, and also affects some people's ability to engage brain areas required for encoding and remembering previous experiences. There is also evidence to show that some people are more susceptible than others to this, which explains why two people can drink the same amount and one is more affected than the other. (Wetherill, 2012)

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Task

Summarise the supporting evidence for the Biological approach to memory.

6. The Cognitive Approach to Memory

SchemasA useful concept from this approach is the schema, that is, a set of ideas and beliefs about something that you have experienced. Cognitive psychologists thinks that long-term memories are based on schemas, meaning that similar memories are stored together.

As our schemas are influenced by culture and expectations, people should remember things better if they are consistent with a schema. This is exactly what was found by memory researchers Brewer and Treyens (1981) who studied recall of objects in an office scene. However, in a similar study, Pezdek et al (1989) directly compared schema-consistent and schema inconsistent items, and found that that inconsistent items were better recalled. They concluded that this is due to more attention being given to items that seem surprising or unusual during the process of encoding. Either way, it is apparent that memory for objects is influenced by expectations from our schemas.

Models of MemoryBecause memory is a hypothetical construct, it does not exist in reality. This makes it difficult to investigate. As a result, cognitive psychology uses models to illustrate how memory, perception, thinking, etc. may work. Models can provide an illustrative approach which is more friendly to those who are meeting the new ideas and theories for the first time. The model approach also lends itself well to evaluation, either of the whole model or of the discrete parts.

(a) The Multi-store Model of Memory (MSM)

Atkinson and Shiffrin (1968) suggest that memory is made up of a series of stores, and describe memory in terms of information flowing through a system.

Accordingly, it can be described as an information processing model (like a computer) with an input, process and output.

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Sensory store

Short-term store

Long-term store

Attention

Elaborate rehearsal

Retrieval

Inat

tent

ion

MaintenanceRehearsal loop

Deca

y/di

spla

cem

ent

Inte

rfere

nce

Information

You won’t remember something if you’re not paying attention to it.

Information is lost due to lack of rehearsal or displacement by new information.Capacity = 7+/-2

Information is lost because of Interference. (Blocking)

Information is detected by the sense organs and enters the sensory memory store. If attended to this information enters the short term memory.

Information from the STM is transferred to the long-term memory only if that information is rehearsed. Atkinson and Shiffrin believed that rehearsal maintains data in short-term memory, and without rehearsal the data is lost within 30 seconds.

Rehearsal

Rehearsal means that information is transferred from short-term to long-term memory where it can last a lifetime.

If rehearsal does not occur, then information is forgotten, lost from short term memory through the processes of displacement or decay.

There are different types of rehearsal: Craik and Watkins (1973):

Maintenance rehearsal is where a word is repeated aloud several times to retain it is short-term memory

Elaborative rehearsal is where information is processed in terms of its meaning.

It is suggested that maintenance rehearsal may maintain information in short-term memory, but elaborative rehearsal is required to make the transfer to long-term memory.

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Task:

Draw the Multi-Store model in your jotter. Annotate your drawing with explanations of each stage and how it works.

Studies supporting Atkinson and Shiffrin’s Multi-store Model (Strengths)

Differences between short-term and long-term memory:

Encoding – Short-term memory relies mainly on acoustic coding. Long-term memory relies mainly on semantic coding (Conrad, 1964 – Baddeley, 1966)

Duration – Information has approximately an 18 second duration in short-term memory (Peterson and Peterson 1959)

Capacity – People remember 7 +/- 2 chunks of information (Miller, 1956)

Further Supporting Research

Glanzer and Cunitz (1966) – study on primacy & recency effects.

Sperling (1960)

Aim: to find evidence of the existence of a sensory memory and its capacity.

Method: Participants were shown 12 letters in 3 rows (4 in each row) for 50 milliseconds. They were then asked what letters they could remember.

Results:People remember seeing more than they can recall, but the image fades during the time it takes to report back four of the items. It’s a bit like trying to read the credits that roll up on the screen at the end of a film. While you are paying attention to one name, others are disappearing off the screen.

Conclusion:Decay happens very quickly in sensory memory (ie. Duration is short) and capacity is very limited.

Other strengths of the Atkinson and Shiffrin’s Multi-store Model

The multi-store model has made an important contribution to memory research. The information-processing approach has enabled psychologists to construct testable models of memory and provided the foundation for later important work.

There is plenty of evidence to support the distinction of a distinction between short-term, temporary, limited-capacity store and a more robust and permanent long-term memory. Case studies of brain damaged patients provide evidence for a separate stores which function independently (e.g. KF’s STM was impaired while his LTM was intact).

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Problems and Limitations of Atkinson and Shiffrin’s Multi-store Model

Unclear whether limited capacity of STM relates to storage capacity or processing capacity.

Craik and Lockhart (1972) suggest that there is not enough distinction between SS, STM, and LTM to actually justify boxes being placed around the stages.

Tulving (1972) – division of long-term memory into semantic and episodic memory; model does not account for this.

If coding in STM is mainly acoustic, how do we understand language?

Some information does not lend itself to rehearsal e.g. smells and yet we remember them – how do they get into LTM?

The model is oversimplified, in particular when it suggests that both short-term and long-term memory each operate in a single, uniform fashion. We now know is this not the case.

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(b) Working Memory Model (WMM)

Baddeley and Hitch (1974) were the first to explore whether short-term and long-term memory are in fact separate stores and whether they have different functions.

Baddeley and Hitch’s Working Memory Model suggests that short-term memory is both complex and flexible and consists of a central control mechanism (central executive) assisted by slave systems.

Working memory is short-term memory. Instead of all information going into one single store, there are different systems for different types of information.

Working memory consists of a central executive which controls and coordinates the operation of two slave systems: the phonological loop and the visuo-spatial sketch pad.

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Components of the WMM:

Central Executive: Drives the whole system (e.g. the boss of working memory) and allocates data to the subsystems (VSS & PL).

It also deals with cognitive tasks such as mental arithmetic and problem solving.

Visuo-Spatial Sketchpad (inner eye): Stores and processes information in a visual or spatial form. The VSS is used for navigation.

The phonological loop is the part of working memory that deals with spoken and written material. It can be used to remember a phone number.

It consists of two parts: Phonological Store (inner ear) – Linked to speech perception Holds information in

speech-based form (i.e. spoken words) for 1-2 seconds.

Articulatory control process (inner voice) – Linked to speech production. Used to rehearse and store verbal information from the phonological store.

The original model was updated by Baddeley (2000) after the model failed to explain the results of various experiments.

An additional component was added called the episodic buffer. The episodic buffer acts as a 'backup' store which communicates with both long term memory and the components of working memory.

It is responsible for integrating & manipulating material; it has limited capacity and depends heavily on executive processing. It binds together information from different sources into chunks or episodes, hence the term ‘episodic’. One of its important functions is to recall material from LTM & integrate it into STM when working memory requires it (e.g. imagining an elephant ice-skating).

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Strengths of the WMM

Evidence to support the phonological loop:Baddeley (1975) word length effect (short words easier to recall than long). Prevention from being able to rehearse words by repeating an irrelevant sound (La-la-la). The word length effect was lost as articulatory suppression fills the phonological loop.

Evidence to support the visuo-spatial scratch pad, and its separation from the phonological loop:Baddeley (1973) Participants were asked to hold a pointer with a moving spot of light whilst visualising the capital letter F as a 3D shape. Tracking and letter imagery tasks were competing for the limited resources of the visuo-spatial scratch pad. Participants found this almost impossible to do. There was no effect when the tracking and verbal tasks use separate components. For example, participants found it easy to remember a list of words read to them, whilst they visualised the block capital letter F.

Brain imaging studies have also been very useful in showing the existence of individual components of working memory. Paulescu et al (1993) used positron emission tomography (a PET scan) to record brain activity when participants were performing either verbal tasks (using the phonological loop) or visual tasks (using the visuo-spatial sketch pad), and found that very different areas of the brain were active during each task. This showed quite clearly that verbal and visual tasks are performed by different brain regions and therefore suggests that the phonological loop and visuo-spatial sketch pad are physically separate from each other as the working memory model suggests.

The working memory model explains a lot more than the multi-store model. It makes sense of a range of tasks - verbal reasoning, comprehension, reading, problem solving and visual and spatial processing. And the model is supported by considerable experimental evidence.

The working memory applies to real life tasks: *reading (phonological loop) *problem solving (central executive) *navigation (visual and spatial processing)

The KF Case Study supports the Working Memory Model. KF suffered brain damage from a motorcycle accident that damaged his short-term memory. KF's impairment was mainly for verbal information - his memory for visual information was largely unaffected. This shows that there are separate STM components for visual information (VSS) and verbal information (phonological loop).

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Limitations of the WMM

Lieberman (1980) criticizes the working memory model as too simplistic. For example; the visuo-spatial sketch pad (VSS) implies that all spatial information was first visual (they are linked). However, Lieberman points out that blind people have excellent spatial awareness, although they have never had any visual information! Lieberman argues that the VSS should be separated into two different components: one for visual information and one for spatial.

There is little direct evidence for how the central executive works and what it does. The capacity of the central executive has never been measured. Baddeley’s theory relies on the existence of something that can never be measured or proved. This is very unscientific.

Working memory only involves STM so it is not actually that comprehensive model of memory (as it does not include SM or LTM). This means the process of encoding STM to LTM is never explained.

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Exam Style Question

Explain and evaluate two theories relating to your optional topic in Individual Behaviour. 20

7. Eyewitness Testimony (application)

Eyewitness testimony is a legal term. It refers to an account given by people of an event they have witnessed. For example; they may be required to give a description at a trial of a robbery or a road accident someone has seen. This could include identification of perpetrators, details of the crime scene etc. Witnesses may also be required to identify perpetrators from a line-up.

Eyewitness testimony is an important area of research in cognitive psychology and human memory. Juries tend to pay close attention to eyewitness testimony and generally believe it to be a reliable source of information.

But is it?

This questioning of the credibility of eyewitness testimony began with Hugo Münsterberg, who first developed the field of forensic psychology. He specifically doubted the reliability of perception and memory in his book "On the Witness Stand" (1908). In it, Münsterberg pointed out the various reasons why eye witness testimony is inherently unreliable. He described how eye witness testimony is inherently susceptible to what he calls

"illusions" where a subject's perceptions could be effected by the circumstances, making their memory of the events that transpired or testimony inaccurate. He stated that with regularity the testimony between two different individuals in the same circumstances can be radically different, even when neither of whom had the slightest interest in changing the facts as remembered. Münsterberg believed this is because memory, when all things are equal, is easily fallible. Because one's memory is affected by the associations, judgments, and suggestions that penetrate into every one of one's observations and taint out memory and our recollection of events.

The Devlin Committee was set up by the British government in 1976 to investigate the use of eye witness testimony in UK courts. It investigated all cases that had gone through the courts in the year 1973. It found that many people had been convicted of serious crimes by eyewitness testimony alone. For example 82% of suspects chosen from an identification parade were convicted and 74% of cases where eye witness testimony was the only evidence were judged guilty. An estimated 222 people convicted in the UK in 1973 were in prison based solely on being identified by a single eyewitness.

A lot of them protested their innocence!

Following the publication of the report, the law was changed regarding convictions in the UK: The Devlin Report recommended that the trial judge be required to instruct the jury that it is not safe to convict on a single eyewitness testimony alone, except in exceptional circumstances or when there is substantial corroborative evidence.

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The case of Marvin Anderson

In December 2001, Marvin Lamont Anderson became the ninety-ninth person in the United States to be exonerated due to post-conviction DNA testing. He was only eighteen years old when he was convicted of robbery, sodomy, abduction, and rape. Anderson was released on parole 15 years later, but it took another four years to be exonerated.

On July 17, 1982, a young woman was raped by a black man

whom she said was a total stranger. After she reported the

crime, a police officer singled out Anderson as a suspect

because the perpetrator had told the victim that he “had a

white girl,” and Anderson was the only black man the officer

knew who lived with a white woman.

Investigation and Trial

Because Anderson had no criminal record, the officer went to

Anderson’s employer and obtained a colour employment

photo identification card. The victim was shown the colour

identification card, along with six black-and-white mug shots,

and identified Anderson as her assailant. Within an hour of the

photo spread, she was asked to identify her assailant from a

line-up. Anderson was the only person in the line-up whose

picture was in the original photo array shown to the victim and

the victim identified him in the line-up as well.

At trial, the victim testified in detail regarding the assault and

again identified Anderson as her assailant. The serology work

(blood and semen recovered from the victim) completed by

the Virginia Bureau of Forensic Science was uninformative.

From the very beginning of the case, people in the community

became aware that the most likely suspect was another black

man named John Otis Lincoln. The bicycle that had been

identified as being used by the assailant was identified by the

owner, who said that Lincoln had stolen it from him

approximately a half hour before the rape. Although Anderson

requested that his attorneys call both the owner of the bicycle

and Lincoln as witnesses, his counsel declined. An all-white

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jury convicted Anderson on all counts and he was sentenced to two hundred and ten years in

prison.

Post-Conviction Investigation

In 1988, John Otis Lincoln came forward and admitted his involvement in the crime in an effort to

clear Anderson. At a state hearing in August 1988, Lincoln confessed and offered details of the

crime under oath and in open court. Nevertheless, the same judge who presided over the original

trial refused to vacate the conviction.

In the years after Anderson’s conviction, when DNA testing had become widely available,

Anderson sought to prove his innocence of the crime. After his lawyers were told by the police,

prosecutor, and court that the rape kit and its contents had been destroyed, Anderson contacted

the Innocence Project and his case was accepted in 1994.

In 2001, Dr. Paul Ferrara, Director of the Virginia Division of Forensic Science, advised the

Innocence Project that certain physical evidence from the case – including sperm samples

recovered from the victim’s body – had been located in the laboratory notebook of the criminalist

who performed conventional serology in 1982. Had that criminalist followed policy and returned

the partially used swabs to the rape kit, all evidence in this case would have been forever lost.

After requests for DNA testing were denied, the Innocence Project, in conjunction with the Mid-

Atlantic Innocence Project, finally won access to DNA testing in 2001. The results excluded

Anderson as the perpetrator and when it was run through Virginia’s convicted offender DNA

database, it matched two inmates. Although the identity of these two men has not been officially

revealed, it appears that one of the inmates is John Otis Lincoln.

On August 21, 2002, Virginia Gov. Mark Warner granted Anderson a full pardon. He had spent

fifteen years in prison and four years on parole fighting to prove his innocence.

So why is eyewitness testimony so bad?

Errors can begin to occur in a person’s recollection almost immediately after the event:

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Errors can happen by what the witness sees, by what the eyewitness hears and sees after the event, and what happens when the person if being asked to recall the information. We will look at a few factors that affect a person’s recollection of events.

Factors Affecting Eyewitness testimony

Anxiety:Anxiety or stress is almost always associated with real life crimes of violence. Deffenbacher (1983) reviewed 21 studies and found that the stress-performance relationship followed an inverted-U function proposed by the Yerkes Dodson Curve (1908). This means that for tasks of moderate complexity (such as EWT), performances increases with stress up to an optimal point where it starts to decline. Clifford and Scott (1978) found that people who saw a film of a violent attack remembered fewer of the 40 items of information about the event than a control group who saw a less stressful version. As witnessing a real crime is probably more stressful than taking part in an experiment, memory accuracy may well be even more affected in real life.

Weapon focus:This refers to an eyewitness’s concentration on a weapon, to the exclusion of other details of a crime. In a crime where a weapon is involved, it is not unusual for a witness to be able to describe the weapon in much more detail than the person holding it!Loftus et al. (1987) showed participants a series of slides of a customer in a restaurant. In one version the customer was holding a gun, in the other the

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same customer held a chequebook. Participants who saw the gun version tended to focus on the gun. As a result they were less likely to identify the customer in an identity parade those who had seen the chequebook version.

Social Pressure:Treatment of witnesses can pressure them into making errors, for example the way a witness line-up is conducted. Wells and Loftus (2012) report how having a traditional six person physical line-up of suspects pressures the witness into choosing somebody and they find it very difficult to respond accurately if the true suspect is not present.

Change Blindness:There have been a number of studies into how people fail to notice changes in their surroundings. The concerning thing for eyewitness memories is that people apparently do not focus much attention on a face unless it is unusual in some way and may even fail to notice that they are looking at a different person unless the actor changes a very obvious category such as race, sex or age. Davies and HINE (2007) showed participants a film of a burglary where the actor changed mid-way through; 61% did not notice the change. Example can be found at www.youtube.com/watch?v=BZ0l9s8_Hmk

Expectations:Brewer and Treyens’s study (1981) study into schemas [see cognitive approach] shows that people’s expectations can affect what they report at a scene. Our culture and life experiences provide a set of expectation about social situations. In a crime, excpectations and prejudice can affected what a witness perceives and what they later report. There is a tendency, according to schema theory, for witnesses to ‘fill in the blanks’ of anything they can’t remember or fully understand.

Reconstructive memory:Many people believe that memory works something like a videotape. Storing information is like recording and remembering is like playing back what was recorded. With information being retrieved in much the same form as it was encoded. However, memory does not work in this way. It is a feature of human memory that we do not store information exactly as it is presented to us. Rather, people extract from information the gist, or underlying meaning. In other words, people store information in the way that makes the most sense to them. We make sense of information by trying to fit it into schemas, which are a way of organizing information.

Schemas are mental 'units' of knowledge that correspond to frequently encountered people, objects or situations. They allow us to make sense of what we encounter in order that we can predict what is going to happen and what we should do in any given situation.

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“Four legs”

“Tail”

“Fur”

Stroke its head saying;

“Who’s a good boy?”

These schemas may, in part, be determined by social values and therefore prejudice. Schemas are therefore capable of distorting unfamiliar or unconsciously ‘unacceptable’ information in order to ‘fit in’ with our existing knowledge or schemas.

This can, therefore, result in unreliable eyewitness testimony.

Race:The cross-race effect (sometimes called cross-race bias, other-race bias or own-race bias) refers to the tendency to more easily recognize members of one's own race. A study was made which examined 271 real court cases. In photographic line-ups, 231 witnesses participated in cross-race versus same-race identification. In cross-race line-ups, only 45% were correctly identified versus 60% for same-race identifications. (Behrman et al, 2001) He found that; an innocent Black suspect has a fifty-six percent greater chance of being misidentified in a police line-up by a white eyewitness than a black eyewitness.Racial expectations can be linked to Reconstructive memory and were very clearly demonstrated in a study by Allport & Postman (1947). When asked to recall details of the picture (right), participants tended to report that it was the black man who was holding the razor. Clearly this is not correct and shows that memory is an active process and can be changed to 'fit in' with what we ‘expect’ to happen based on your knowledge and understanding of society (e.g. our schemas). In this case the (mostly) white participants ‘expected’ the black man to be the one holding the razor, therefore that’s what they remembered.

Age of witness:Children, according to research, are generally seen as unreliable witnesses. Kent & Yuille (1987) asked children to identify from a set of photographs a person they had seen earlier. They found that 9 year old children were far more likely than 14 year olds to identify someone from the photo set even when the target person was not present - in other words, younger children were less likely to say that the person they had seen earlier was not present in the photo set. This followed earlier research that showed children as young as 5 were as able to correctly identify people they had seen

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In his famous study 'War of the Ghosts', Bartlett (1932) showed that memory is not just a factual recording of what has occurred, but that we make “effort after meaning”. By this, Bartlett meant that we try to fit what we remember with what we really know and understand about the world. As a result, we quite often change our memories so they become more sensible to us.

His participants heard a story and had to tell the story to another person and so on, like a game of “Chinese Whispers”. The story was a North American folk tale called “The War of the Ghosts”.

When asked to recount the detail of the story, each person seemed to recall it in their own individual way.

With repeating telling, the passages became shorter, puzzling ideas were rationalized or omitted altogether and details changed to become more familiar or conventional.For example; the information about the ghosts was omitted as it was difficult to explain, whilst participants frequently recalled the idea of “not going because he hadn’t told his parents where he was going” because that situation was more familiar to them.

For this research Bartlett concluded that memory is not exact and is distorted by existing schema, or what we already know about the world.

earlier, and so it is not a problem with children’s memories that causes them to identify wrong people, but it is more likely that they feel less able to admit to an adult that they cannot do the task and so they just pick any photo when the target one is not there.

Ceci & Bruck (1993) found that a biased interviewer can cause children to change their memories through use of leading questions; repeated questioning often results in children changing their stories as it suggests to them that they are wrong and they want to please the authority figure asking the questions; stereotypes can be introduced so children will report actions in a negative way about a person they are told is ‘bad’; children often incorporate things their peers tell them in to their memories; and if a child is asked to think hard about something then their imaginations may take over and they will recall fictitious events.

Leading Questions:Psychologist Elizabeth Loftus has been particularly concerned with how subsequent information can affect an eyewitness’s account of an event. Her main focus has been on the influence of (mis)leading information in terms of both visual imagery and wording of questions in relation to eyewitness testimony. Loftus’ findings seem to indicate that memory for an event that has been witnessed is highly flexible. If someone is exposed to new information during the interval between witnessing the event and recalling it, this new information may have marked effects on what they recall. The original memory can be modified, changed or supplemented. The fact the eyewitness testimony can be unreliable and influenced by leading questions is illustrated by the classic psychology study by Loftus and Palmer (1974) Reconstruction of Automobile Destruction.

Loftus and Palmer (1974)

Aim: To test their hypothesis that the language used in eyewitness testimony can alter a person’s memory.

Experiment 1:

Method: 45 American students formed an opportunity sample. This was a laboratory experiment

with five conditions, only one of which was experienced by each participant (an independent measures experimental design).

7 films of traffic accidents, ranging in duration from 5 to 30 seconds, were presented in a random order to each group.

After watching the film participants were asked to describe what had happened as if they were eyewitnesses. They were then asked specific questions, including the question “About how fast were the cars going when they (smashed / collided / bumped / hit / contacted) each other?”

Thus, the IV was the wording of the question and the DV was the speed reported by the participants.

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Results: The estimated speed was affected by the verb used. The verb implied information about the speed, which systematically affected the participants’ memory of the accident.

Participants who were asked the “smashed” question thought the cars were going faster than those who were asked the “hit” question. The participants in the “smashed” condition reported the highest speed estimate (40.8 mph), followed by “collided” (39.3 mph), “bumped” (38.1 mph), “hit” (34 mph), and “contacted” (31.8 mph) in descending order.

Conclusion:The results show that the verb used in questioning conveyed an impression of the speed the car was actually travelling and this altered the participants' memories.

Experiment 2:

Method: 150 students were shown a one minute film which featured a car driving through the

countryside followed by four seconds of a multiple traffic accident. Afterwards the students were questioned about the film. The independent variable was

the type of question asked after the video. It was manipulated by asking 50 students 'how fast were the car going when they hit each other?', another 50 'how fast were the car going when they smashed each other?', and the remaining 50 participants were not asked a question at all (i.e. the control group).

One week later the dependent variable was measured - without seeing the film again they answered ten questions, one of which was a critical one randomly placed in the list: “Did you see any broken glass? Yes or no?"

There was no broken glass on the original film.

Results:Participants who were asked how fast the cars were going when they “smashed” were more likely to report seeing broken glass.

Conclusion:This research suggests that memory is easily distorted by questioning technique, and information acquired after the event can merge with original memory causing inaccurate recall or

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“Smashed” “Hit” Control

Saw smashed glass (/50) 16 7 6

reconstructive memory.The results from this second experiment suggest that this effect is not just due to a response-bias, because leading questions actually altered the memory a participant had for the event (it added in extra features that were not part of the question asked of them).

The addition of false details to a memory of an event is referred to as confabulation.

Changes to the legal processBecause of these issues, and the findings of the Devlin Report (1976), the methods of gathering eyewitness testimony have been changed in the UK. These include:

Implementing the use of Cognitive interviewing. This involves making sure that the type of questioning used is more neutral in its language, and avoiding direct questions. For example; “was the accused wearing a green shirt?” is replaced with “what was the assailant wearing?”

Line up’s are now conducted differently; rather than seeing 6 suspects at a time, each suspect is presented one at a time, usually through photos, and the witness is required to answer with a Yes/No judgement each time.

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Tasks:

1. What is EWT?2. What impact has Munsterberg’s work and the Devlin Report had on the power of EWT in

criminal convictions?3. Explain 4 factors that affect eyewitness testimony.4. Outline one of Loftus and Palmer’s studies, including an evaluation5. Why does the presence of a weapon make eyewitness statements less accurate?6. What changes could be made to police practices to reduce errors in EWT?7. Explain what a cognitive interview involves.8. What important differences are there between lab experiments of EWT and real crimes?9. Read p144 of CfE Higher textbook and make notes.

Exam Style Questions

1. Choose a topic from Individual Behaviour other than sleep, dreams and disorders. Explain how this topic can be applied to the real world. [10 marks]

2. Explain a topic from Individual Behaviour other than sleep, dreams and disorders, referring to at least two approaches. [16 marks]

3. Discuss two theories relating to your chosen topic in Individual Behaviour. [12 marks]

Exam Tip:For an exam answer on the application of memory, you should structure your answer around the

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Exam Tip:For an exam answer on the application of memory, you should structure your answer around the