Memory

Without memory, we'd have no concept of ourselves, what experiences we've had during our lives and how that links us to our current identity.

Scientists learn about memory from those who've had head traumas. Even those who've had the worst head injuries rarely lose all the knowledge they've gained in a lifetime. Instead, they may suffer impairments to different parts of memory: short term or long term.

This shows that memory is made up of different components.

Our memory performs many varied tasks and deals with so many different types of information, so psychologists believe it's a collection of different processing systems.

Many models and theories have been put forward to describe these systems.

Memories are formed in a way that involves a number of processes.

First, we have to have an experience, and then the following happens:

1) Encoding - The process whereby we transform information recieved into a meaningful form that allows us to store it.

2) Storage - Holding/storing the information. However, some psychological changes occur in order for the information recieved to be stored.

3) Retrieval - Bringing the memory out of storage and restoring the information so that it can be used where needed.

Atkinson & Shriffin (1968) created The Multi-Store Model, which is one of the best known early models of memory. It assumes that memory consists of 3 seperate 'stores':

• Sensory Memory (SM) / Sensory Register (SR)
• Short-Term Memory (STM)
• Long-Term Memory (LTM)

Research into these stores has concentrated on the type of encoding, capacity and duration of each one.

Encoding - The form in which information is represented, e.g. acoustic or visual.

Capacity - How much that store of memory can hold.

Duration - How long memory can last for in that store.

Maintenance Rehearsal - Repeating something that you must remember over and over again to keep it looping around your STM, which helps you to prevent forgetting it.

Example: 

• A friend tells you her phone number. Your pen and paper is in the car so you must try to remember it until you can write it down.
• This information has come to you via sensory memory; you heard your friend say her number.
• Because you want to remember it, you give it attention, which pulls it into your STM.
• You must keep looping it round in your STM by repeating it over and over until you write it down - this is known as maintenance rehearsal.
• If you get into the car with no distractions, you can remember the number and write it down.
• However, if you meet a new friend and talk to them, the number is now lost; it has been displaced as you had to use your STM to hold the new conversation, and you can't hold both the phone number and the conversation in your STM at the same time.

According to Atkinson & Shriffin, rehearsal or repetition of material is the key to getting information from the STM to the LTM.

Support:

+) Evidence from lab studies on primary/recency.

+) Evidence from case studies on brain damaged patients.

+) Support from neurophysiological studies that show different parts of the brain being active when participants are performing STM and LTM tasks.

All of the findings from the studies above give good support for a distinction between STM and LTM.

Criticism - Shallice & Warrington (1970):

-) They think the model is oversimplified and doesn't take into account the complexity of memory.

-) Evidence of this comes from their study of a patient known as KF, who suddered brain damage in a motorcycle accident, which severly impaired his STM but left his LTM intact.

-) The Multi-Store Model would predict this couldn't happen since all information in the LTM must pass through the STM.

Criticism - Shallice & Warrington (1970) (cont.):

-) KF could make new long-term memories (as long as information was presented visually) doesn't agree with this idea which is one of the core assumtions of the Multi-Store Model.

Criticism - Ruchkin et al (1999):

-) Gave further evidence against the idea of information only flowing one way through the system.

Criticism - Craik & Tulving (1975):

-) Another criticism is that the role of rehearsal has been overstated.

-) Theorists today believe that memory is an active process and that simple repetition of information to be remembered is the least effective strategy.

Sensory memory involves input from the environment. There's a large amount of information available to our senses at any given time, so when we wish to remember something, we select the relevant information for processing in the memory system.

It consists of a set of stores which hold information coming from the environment for fractions of a second. This means that the information we wish to remember is stored in the form in which it was recieved, which is either the iconic store, the echoic store, or the haptic store.

Iconic Store - For visual information.

Example: Looking at a poster or a picture that we want to recall.

Echoic Store - For auditory information.

Example: A friend telling us their phone number so we can recall it soon to write it down.

Haptic Store - For tactile information.

Example: Remembering our PIN number by remembering the sequence of buttons  we press on an ATM.

Iconic Memory Study - Sperling (1960):

Method:

• He tested iconic memory by presenting participants with grids of letters for very short periods of time (50 milliseconds).

Findings:

• He found that people could retain 4 items for up to 1 second.

Later studies of sensory memory have confirmed Sperling's findings and have concluded that sensory memory can:

• Retain items for about 2 seconds.
• Only record information passively (i.e. we can't control it).
• Only retain information in a relatively unprocessed form.

Conclusion: SM is made up of seperate stores for visual, auditory and tactile information. Only a fraction of the items registered here are ever passed onto the STM; the rest are lost.

The capacity of the STM has been known for a long time; it is around 7 items.

Forgetting in STM occurs due to displacement. Once the STM capacity is reacher, any new information displaces/pushes out information already stored there. This suggests that our STM typically has a maximum capacity.

The Digit-Span Technique - Jacobs (1887):

• He created a technique to measure the capacity of the STM.
• It has been widely used ever since and has become known as the Digit-Span Technique.
• Using this method, he found that the average STM capacity is around 7 items.

The Magic Number 7 & Chunking - Miller (1956):

• He termed Jacobs' finding of the STM capacity as the 'magic number 7'.
• He showed capacity could be increased by chunking items together, e.g. 12 digits could be chunked into 3 memorable dates.
• These chunks take up less STM capacity slots than if there weren't any chunks.

Crisicism of Chunking:

Simon (1979):

• He questioned the idea of a chunk being 1 unit of STM capacity.
• He found that capacity was smaller for lager chunks of information (8 words phraseS) than for smaller ones (single words).
• Therefore, it seems that the size of the chunks matter; we can't hold as many large chunks as we can smaller ones.

Possible Factors Affecting STM Capacity:

1) The Influence of our LTM - Whether or not we want to transfer information from out STM into our LTM.

2) Reading out Loud - Can this help to expand the capacity of our STM?

3) Pronunciation Time - Does this have an impact on our auditory store in our sensory memory?

4) Individual Differences - Can we generalise about memory or is this a quality that varies greatly from one individual to another, in the way that physical characteristics do?

The duration of STM appears to be around 6-12 seconds (according to Peterson & Peterson).

Peterson & Peterson believe STM consists of a memory trace which decays if not rehearsed.

Memory Trace - Peterson & Peterson (1959):

Method:

• The experiment consisted of participants seeing trigrams (groups of 3 unrelated consonants, e.g. 'RBQ').
• The participants then had to try to repeat the trigrams after intervals of 3, 6, 9, 12 or 18 seconds, during which rehearsal was prevented.

Findings:

• The longer the time between learning and recall, the more trigrams were lost.
• This suggests that the memory trace did indeed decay with time.

Criticism of Memory Trace:

• Peterson & Peterson's experiment has been criticised as it's not possible to rule out the influence of limited capacity.
• Also, since the same participants were used for each trial, it's possible that the trigrams learned from earlier on trials interfered with the processing of new ones on subsequent trials.

Possible Factors Affecting STM Duration:

1) Rehearsal - Does rehearsing/repeating information to ourselves prolong the length of time we can remember it for?

2) Intention to Recall - If we want to recall something because it has significance or importance to us, e.g. a birthday, does that increase the length of time that we can remember it for? 

3) Amount of Information to be Recalled - Can we remember many items for a short time or one items for longer? Or are these factors not related in this way?

The STM encodes acoustically.

Conrad (1964):

• Investigated encoding in the STM.
• He found that on STM tasts, participants made acoustic errors, i.e. they substituted letters which sound alike rather than ones which look alike, even when the letters were presented visually.

Conclusion - This experiment shows that the STM encodes acoustially. Regardless of the original format of the information that we want to remember, it is encoded into acoustic data when transferred into the STM.

It's not possible to quanitfy the exact capacity of the LTM, as there seems to be no upper limit to what we can store.

Because of the apparently limitless capacity, forgetting in the LTM doesn't often occur due to displacement (as it does in the STM). However, forgetting can occur in the LTM when similar types of information are stored, causing confusion. This is known as interference.

Types of LTM - Tulving (1974):

1) Episodic - Part of the LTM responsible for storing information about events (i.e. episodes) that we've experienced in our lives. Involves conscious thought, such as a memory of an 18th birthday.

2) Procedural - Part of the LTM responsible for knowing how to do things, so it's not conscious but rather automatic. For example, procedural memory would involve knowledge of how to drive a car.

3) Semantic - Part of the LTM responsible for storing information about the world that involved conscious thought. This would include things like knowing about the meaning of words.

Establishing the duration of the LTM is also problematic, since it can last a whole lifetime.

Duration of LTM - Bahrick et al (1975):

• Found that participants who tested on a recall test on recall of photographs of their classmates performed well even at around 34 years after graduation.
• Participants did better on recognition tasks where they had to match a photo to a name, rather than recall tasks in which they simply had to list their classmates without the aid of picture cues.
• However, there was a decline in performance of this test after about 47 years.

Evaluation:

+) Unlike many studies of memory, this one used meaningful stimulus material (memories from participants' own lives), rather than unrelated lists of letters or words. This could indicate that information which is emotionally/personally significant to us is easier for us to remember.

-) However, it was difficult to establish whether the decline in memory after 47 years reflected the limits of the LTM duration, or a more general decline in memory processing with age.

Possible Factors Affecting LTM Duration:

1) The Depth of Learning - Does how well we think we have learnt something make a difference to the length of time that we can remember it for?

2) The Pattern of Learning - Does the learning method affect the LTM duration?

3) The Nature of the Material to be Remembered - Do we remember some kinds of information in our LTM more easily than others, and if so, why is this?

Encoding in the LTM is believed to be mainly semantic (according to meaning). However, it is also known that the LTM can use acoustic and visual encoding as well as semantic.

Baddeley (1966):

• Found that participants performing LTM tasks made more errors when recalling lists of semantically similar words (such as big and huge), than when recalling lists of semantically dissimilar ones.

Serial Position Effect - The tendency to recall the first and last items in a series best, and the middle items worst.

The STM and the LTM being two different stores has been shown using tasks where participants are given words and then allowed to recall them in any order (free recall).

When the frequence of recall of each word is plotted against its position in the list, a characteristic serial position curve is produced. This describes the fact that the words at the beginning and the end of the list are remembered well, but those in the middle of the list are often lost.

This is because:

• Participants start to rehearse the words at the beginning of the list until their STM capacity is exceeded. These words have therefore been processed in the LTM (this is the primacy effect).
• Words at the end of the list are remembered as they're still active in the STM (the recency effect).

The Distractor Task - Glanzer & Cunitz (1966):

Method:

• Gave participants a distractor task after presenting them with a word list which they then had to recall.
• The task was designed to prevent rehearsal of the lew few items on the list.

Findings:

• They found that the recency part of the curve was lost, whilst the primacy part remained unaffected.
• Immediate recall of the words gave a standard serial position curve (when there was no distractor task).
• Whereas recall after a 30 second delay and with the distractor task successfully disrupted the recency effect.

Conclusion: The fact that researchers were able to manipulate the ability of one memory store whilst leaving the other intact provides support for there being two seperate stores.

Neurophysiological Case Studies:

Further support for there being a distinction between STM & LTM comes from neurophysiological case studies on people who have suffered brain damage.

Milner (1966):

• A patient known as HM underwent surgery to remove his hippocampus on both sides on the brain in attempt to cure his epilepsy.
• This left him with severe anterograde amnesia (which meant that he couldn't store new memories).
• His STM was left intact and he could retain verbal information for about 15 seconds.
• However, he could not transfer information into his LTM, or if he could he couldn't retrieve it.
• Blakemoor (1988) described HM's memory for new events, faces, phone numbers and places as settling in his mind for just a few seconds before trickling away again.

Brain Scanning Case Studies:

Brain scanning studies also support there being a difference in the stores of the STM & LTM.

Squire et al (1992):

• Used PET scans to show that the pre-frontal cotext of the brain is active during STM tasks, while the hippocampus is active during LTM tasks.

Working Memory - The process that takes place when we continually focus on material for longer than the STM alone will allow.

Baddeley & Hitch (1974) developed a model of short-term memory, which they called working memory. This model was an alternative to the short term store as referred to in the multi-store model. They argued that the STM in the Multi-Store Model was far too simple and needed to be further developed.

They were interested in the function (what is it for?), rather than the structure (what is it like?) of the STM. 

They argued that the working memory is short term memory, but instead of all information going into one single store, there are different sub-components for different types of information. 

This idea shows that the STM is an active store used to hold information from sensory memory and the LTM, whilst it's being manipulated for present use. It's also involved in reasoning, understanding and learning.

Baddeley has carried out a number of different investigations which show that working memory consists of several different components:

1) Central Executive (the pre-frontal cortex) - This is involved in all tasks requiring attention. It allocates resources to other stores and acts as the controller for working memory.

2) Visuo-Spatial Sketchpad (also known as the inner eye) - This holds visual information such as size, shape and colour. It consists of 2 sub-components, the 'inner scribe' and the 'visual cache':

• Inner Scribe - Deals with spatial movement information.
• Visual Cache - Stores information about forms and colour.

3) Phonological Loop (also known as the inner voice) - This holds verbal information in speech-based form. It has 2 sub-components, the 'phonological store' and the 'articulatory loop':

• Phonological Store - Holds auditory memory traces that are subject to rapid decay. Evidence suggests that the capacity of the phonological loop is the number of words that can be articulated in 1.5 seconds.
• Articulatory Loop - A store that can revive auditory memory traces by sub-vocal repetition.

Dual-Coding Task - A task that requires an individual to perform 2 tasks simultaenously, in order to compare performance with single-task conditions.

Much of the research into working memory has been carried out using the dual-task technique.

It has been designed to show that two tasks can be carried out simultaneously with little or no effect on performance of either task, providing they use different components of the STM.

However, performance of two tasks that use the same component of STM will be affected in the dual-task.

This can show researchers which parts of memory are used for completing which kinds of tasks.

Evaluation:

+) Has a lot of advantages over the concept of STM described by the Multi-Store Model.

+) Explains our ability to carry out tasks such as mental maths by holding information from both our sensory memory (e.g. the factors in the sum) and LTM (e.g. the knowledge of how to solve it) whilst being able to manipulate it.

+) Offers a new interpretation of the study of the patient KF, who had damage to just the verbal part of his STM, which is why he could still retain information that was presented visually.

+) It's had useful applications to real life.

-) The central executive had been more difficult to investigate. Tasks have been devised which demonstrate it's function, but it's exact role remains unclear.

-) It isn't able to offer complete understanding of how memory works, and does little to explain the role of the LTM.

With this in mind, the original model was updated by Baddley (2000) with the concept of  the 'Episodic Buffer'.

The Working Memory Model does little to explain the role of LTM, so it was updated by Baddeley (2000) with the concept of the Episodic Buffer.

The Episodic Buffer acts as a 'back up' store which communicates with both the LTM and the components of the Working Memory.

It is described as a system that is fed by the sub-components, that links to the central executive and plays an essential role in conscious awareness.

Episodic - Refers to how information is bound together in chunks/episodes, which links to the central executive and is responsible for our conscious awareness.

Buffer - Refers to how information is temporarily held in a multi-dimentional way.

Evaluation:

+) Much of the work on this model has used lab studies which are well controlled and produce reliable results.

-) However, these studies can lack ecological validity, since the tests given to perform are rather artificial and don't represent memory in everyday life.

This shows that appropriate experiment design is key, and trying to replicate real life experimental conditions increases the validity of the resulting data.

There are 2 main explanations as to why we forget:

1) The information that was stored in our memories is no longer available: The information isn't availagle when you need it, but may be accessible at a later date.

2) The memory/information that has been forgotten has been permanently forgotten: Any physical traced of the memory are gone. In such instances, the information is not available at all.

It's argued that how or why we forget is dependent on whether what has been forgotten was stored in the STM or the LTM.

In the 1930's-1950's, psychologists believed that forgetting was caused by 'interference'.

This is based on the idea that memory can be interfered with by what we have learnt previously or by what we learn in the future. Therefore, memory can become combined with other information or confused by distorted memories.

According to interference theory, memories can interfere with each other and cause forgetting.

The interference theory suggests that there are 2 ways that interference can occur:

• Proactive Interference (pro=forward).
• Retroactive Interference (retro=backwards).

Proactive Interference: Is the inability to be able to learn something new because something that had been learn previously (an old memory) interferes with the learning of something new (a new memory).

Retroactive Interference: Is forgetting something learnt previously because of learning a new task. The later learning interferes with earlier learning.

Underwood & Postman (1960):

Method:

• Participants were split into 2 groups: A and B. 
• Group A had to remember a list of paired words, e.g. cat & tree, jelly & moss, book & tractor.
• They were then asked to learn a second list of paired words, e.g. cat & glass, jelly & time. Here the paired words were different to the first list.
• Group B (control group) had to learn the first list of words only and wasn't given the second list.
• All of the participants were then asked to recall the words on the first list.

Findings:

• The recall of Group B was more accurate than that of Group A.

Conclusion: The findings suggest that having to learn a second list interfered with the ability to recall the first list, and is therefore an example of retroactive interference.

Underwood & Postman (1960) (cont.):

Evaluation:

-) This was a lab study and therefore artificial.

-) Baddeley (1990) states that the tasks given to participants were too close to each other, and in real life these kinds of events are more spaced out.

• Anderson (2000) has tried to address the issues raised above by investigating actual 'real life' occurences and the outcomes support the interference theory.

Interference is thought to be more likely to occur when the memories are similar.

• Baddeley (1999) found people sometimes forgot things and found it difficult to remember certain information if elements of what was being remembered were familiar.

Example: Trying to remember the name of a place you've visited that is very similar to the name of somewhere else.

Retrieval Failure - When information in the LTM can't be accessed or retrieved because the 'retrieval cues' are not present at the time.

Retrieval Cues - When we store a new memory, that memory will be stored with details and information with it, and these are retrieval cues.

There are 2 types of retrieval cues:

• External/Context: Seeing or smelling something that is associated with the memory that triggers off a cue/s.
• Internal/State: Experiencing an emotion, feeling or mood that triggers off a cue/s.

Tulving (1974) argued that information from a memory is more likely to be retrievable if the actual cue was present at the time at which the information was encoded.

Example: If a man proposed to a womens when their favourite song was playing in the background, both are more likely to remember the details of the ebven when they again hear the song (the song is regarded as the retrieval cue). 

One practical application of memory research has been in eyewitness testimony (EWT).

Eyewitness Testimony - Refers to an account given by an individual of an event or occurance that they have witnessed.

Inaccurate EWT can have serious consequences, leading to wrongful convictions and even the death penalty in the USA. The factors affecting the accuracy of EWT include:

• Leading Questions.
• Misleading Information
• Misattribution Errors.
• Effect of Schemas.
• Anxiety & Weapons Effect.
• Age of the Witness.

There's been much research carried out into why EWT can be unreliable & factors that can effect it. 

Rattner (1988) reviewed 205 cases of wrongful arrests and found that this was due to mistaken EWT in 52% of the cases.

Memory isn't a static record of an event. Unlike photographic or CCTV evidence, memory is an active process.

There is evidence that some factors can change the way in which we recall our memory, including:

• Our previous experiences.
• The stereotypes we hold.
• The emotions that we felt at the time of the event.
• Post-event information. 

It's therefore difficult to know which is the original memory and which is the one that's been altered by the passage of time and by later life experiences (such as information about the same event which you've recieved from other sources or your changed emotions about the event in question).

This alteration of memory after the event has implications for the accuracy of EWT. If witnesses were given wrong or misleading information during questioning, perhaps by a source which they consider more authoritative, it could have the potential to change their recollection of an event.

Further work on EWT has shown that it's not just the retrieval stage of memory that is vulnerable. 

Factors affecting the accuracy or recall at each stage of memory:

Encoding:

• Poor viewing conditions.
• Effect of schemas.
• Anxiety/stress & the weapons effect.

Storage:

• Misleading information.
• Misattribution errors.

Retrieval:

• Leading questions.

(Reconstruction of Car Accident Experiment)

Leading Question - A question that prompts or encourages the answer that is wanted by the person asking it.

Leading Questions Study - Loftus & Palmer (1974):

Question - Can leading question bias how a witness answers?

Method:

• They showed participants a film of a car accident and then asked them how fast the cars were travelling when they hit each other.
• All participants were asked the same question, except that the verb 'hit' was replaced with 'smashed', 'collided', 'bumped', or 'contacted'.

Findings:

• Their findings showed that the word used in questioning affected the estimations of speed given by the participants.

(Reconstruction of Car Accident Experiment, cont.)

Results:

• Verb used - Contacted      =       Average Speed Estimated - 31mph.
• Verb used - Hit                   =       Average Speed Estimated - 34 mph
• Verb used - Bumped         =       Average Speed Estimated - 38 mph
• Verb used - Collided         =       Average Speed Estimated - 39 mph
• Verb used - Smashed       =       Average Speed Estimated - 41 mph

When asked 1 week later if they'd seen any broken glass in the original film, participants who were given the word 'smashed' were more likely to answer 'yes', even though there had been no glass in the film at all.

Conclusion: The results show that subtle changes in the wording of questions can change perceptions.

Loftus & Palmer gave 2 explanations for why leading questions influence EWT:

1) Response-bais Factors - The leading question may have simply influenced the answer a person gave (a response-bias). The question used influenced or generated a bias in terms of the person's response.

Example: When a witness is trying to recall the amount of force exerted by one person in relation to another in a fight, their account can be influenced or biased by the words used to describe the occurence, such as the difference between someone being 'slapped' and 'struck'.

2) The Memory Representation is Altered - The leading question changes the individual's perception of the incident. Critical verbs could result in someone having a perception of an incident that is more serious than the actual incident itself, and this is then stored in the individual's memory of the incident. This shows that even subtle changes to the wording of a question can affect EWT.

Example: "The victim suffered a broken nose" when compared to "the victim suffered a factia fracture."

(Barn Experiment)

Question - Can false information given post-event change the original memory?

Misleading Information - Any information that leads you into giving a particular response, as opposed to a necessarily accurate response.

Method:

• Participants were asked about the speed of a white sports car after watching a film showing this car travelling along a road.
• Half of the participants were asked about the car passing a stop sign, whereas the other half were asked about it passing a barn.

Findings:

• 17% of the 'barn' group reported seeing a barn in the film compared to only 3% in the 'stop sign' group.
• There had been no barn in the original film.
• The 'barm' group had added the misleading post-event information to their original memory, whereas the 'stop sign' group had not.

(Barn Experiment)

Conclusion: Misleading post-event information can change an individual's original memory.

Evaluation:

-) It was a lab study and therefore artificial; it lacked ecological validity.

-) There were high demand characteristics.

-) Deception was used: the researchers were not able to give away the precise nature of the study beforehand.

+) However, participants were debriefed afterwards.

High Demand Characteristics - A high demand that participants act the way that they think they should within the context of the study.

Misleading information can cause inaccurate recall of events because it leads to 'source misattribution'. In other words, participants who are given post-event information that isn't consistent with their own memory get confused as to where they enountered each memory.

Misleading Information - Any information that leads you into giving a particular response, as opposed to a necessarily accurate response.

Source Misattribution Error - The ability to remember information, but being wrong about the source of that information.

Loftus believed this happens because the original memory gets overwritten/altered by the misleading information, and replaced by the new, false memory, which is now believed to be their own recollection of events.

However, not all people are equally as prone to source misattribution errors. Case studies show that people are more easily prone if:

• The person has poorer general recall of an event.
• The person scores highly on tests of imaginary vividness.
• The misleading information is not blatantly wrong.

Barlett (1932) suggested that instead of storing exact replicas of events, we store what he called 'reconstructive memories' which are based on our interpretations of events, which are stored in schemas and created using knowledge that we already have stored in our memories.

Schemas - Mental concepts that informs a person about what to expect from a variety of experiences and situations. They are developed based on information provided by life experiences and are then stored in memories. 

They enable us to process new information according to what we already have stored about previous, similar situations and help us to fill in any 'gaps' in the information available to us.

Example: 

• Your friend tells you that the film he saw last night was good but he missed the start because the service as the 'Taj Mahal' was slow.
• You  know that 'service' & 'Taj Mahal' refers to a restaurant instead of the actual Taj Mahal or any other a bar/cafe without a second thought, due to schemas.

Example (cont.)

• This is because you have a restaurant schema stored in your memory which you can refer to, and you're able to 'fill in the gaps' or infer information based on the cues you recieve from others and your surroundings and with the aid of your schemas.

Schemas that we have stored about other groups of people, often containing negative information, are called stereotypes.

Brewer & Trevens (1981) - Investigated the effects of schemas on visual memory:

Method:

• They asked individual participants to wait in a room for 35 seconds.
• The room was designed to look like an office and contained 61 objects, some of which were consistent with an office schema (e.g. a desk, a typewriter etc.) and some of which were not (e.g. a skull, a brick and a pair of pliers etc.)
• Participants were later given an unexpected recall test.

Findings:

• Participants were more likely to recall the typical office items and less likely to recall items inconsistent with an office schema e.g. pliers.
• Errors in recall typically involved substituting schema-consistent items, i.e. recalling typical office items but which weren't actually present in the room.
• 8 participants recalled the bizarre item, the skull.

Conclusion - This shows that we do use schemas when encoding information, but will also pay attention to highly bizarre or atypical details.

List (1986) - Applied schemas to EWT.

Method:

• She asked people to rate various events in terms of their probability in a shoplifting scenario (and therefore eliciting their shoplifting schema; what people expected would happen in a shoplifting scenario).
• She then devised a video showing 8 different acts of shoplifting, incorporating some of the events previously rated as high probability and some rated as low probability.
• She then showed the video to a new set of participants and tested their recall one week later.

Findings:

• They were more likely to recall high probability events than low probability events.
• Any substitution errors made tended to involve high probability events.

Conclusion: This study shows that schemas do effect what we recall, which can effect EWT.

Cohen (1993) - Suggested 5 ways that schemas can lead to inaccurate memory recall:

1) We tend to ignore elements of an event that don't fit in with our currently activated schema.

2) We can store the central features of an event without having to store the exact details.

3) We can make sense of what we have seen by 'filling in' (inferring) missing information.

4) We distort memories of events to fit in with prior expectations (e.g. remembering a robber wearing a balaclava when he in fact wore a cap, due to schema).

5) We may use our schema to provide us with a best guess if we can't recall the exact information.

Evidence about the effects of anxiety and stress on the accurary of EWT is contradictory.

Lab studies suggest that anxiety can impair recall.

Real life studies often show that anxiety of an event can enhance recall. This may be because events are so traumatic that they're 'seared' into their LTM, making memories highly accurate and long lasting (but also hugely damaging to the individual and therapy may be required).

For example, a study by Loftus & Burns (1982) showed that the 'weapon effect' interferes with witness' ability to recall.

However, a study by Christianson & Hubinette (1993) showed that high levels of anxiety/stress during an incident doesn't always mean they won't be able to recall details of the incident with a good level of accuracy.

Clifford & Scott (1978):

• They had a group of people watch a film of a violent attack.
• They found that people remembered fewer of the 40 items of information about the event than a control group who saw a less violent and stressful version.

Yuille & Cutshall (1986):

• In their study, they found that witnesses who had seen a real life shooting outside a shop in Canada were able to recall and give high levels of accuracy regarding the incident.
• Even when the witnesses were re-interviewed 5 months later, they still had a good level of recall despite the stress and anxiety they had experienced at the time.
• This suggests that we should reconsider the extent to which stress influences eyewitness memories.

Conclusion - These studies show that stress & anxiety can either improve the recall of the event in question, or worsen it.

Weapons Effect Study - Loftus (1979):

Method:

• In a lab study, participants were made to sit outside a laboratory.
• They were led to believe that they were listening to a genuine conversation inside the lab, followed by them witnessing a man leaving the lab.
• In one condition, participants heard a calm discussion and saw a man with sweaty hands leave.
• In another condition, there was a heated exchange followed by the sound of smashing glass and furniture being turned over. The man leaving the lab was holding a bloody knife.

Findings:

• The group who had heard the calm exchange were much better at identifying the man from a series of photos than the group who heard the heated exchange.

Conclusion - Loftus believed that the 'weapon effect' can affect witnesses' ability to recall certain parts of the incident in question, as the weapon brings attention away from other aspects of the incident.

It's generally believed that children don't make as reliable witnesses as adults. However, there are some cases/crimes where only child witnesses were present (e.g. some abuse cases). Therefore, psychologists study the accuracy and impact of children's testimony at each stage of the process, i.e. encoding, storage and retrieval.

Encoding:

Ceci & Bruck (1993) believe children may be inaccurate at providing EWT as they lack the appropriate schemas to help them interpret a situation. However, this could make them more accurate.

Storage:

Thompson (1988) believes that the longer the time between the encoding of a memory and its later retrieval, the more likely retrieval is to be inaccurate. This is the case for both adults and children, although it seems that children's memories are more effected by retrieval delay than adult's memories. The type of information stored is also a factor. For example, as storage interval increases, descriptions of people become less accurate than details of actions.

Retrieval

It's believed that children leave out more details than adults, but relevant cues can help to jog their memory. Children are more susceptible to leading questions than adults.

Leichtman & Ceci (1995) found that if 3 and 6 year olds were given misleading information in questions they incorporated it into their memory.

Poole & Lindsay (2001) found that children aged 3 to 8 incorporated elements of a story read to them by their parents into their memories of a science demonstration watched earlier. When asked about the source of the information (source monitoring) the older children were able to remove the post-event items.

This suggests that younger children are more susceptible than older children to the effects of misleading post-event information.

Conclusion - All of these studies suggest that younger children are more suscpetible to misleading information. Also, children's memories are more affected by retrieval delay than adults, they generally leave out more details in recall than adults and they're more susceptible to leading question.

It is believed that elderly witnesses may also experience errors of recall.

Yarnley (1984):

• In this study, participants were shown a staged event.
• When questioned afterwards, the study found that 80% if elderly participants failed to mention that the attacker held a knife, compared to only 20% of younger adults.

Cohen & Faulkner (1989):

• Conducted a similar study where participants were shown a film of a kidnapping.
• A narrative account of the events shown was then read to the participants, with half being given an accurate account of the film and half given a misleading one.
• The elderly participant's recall was found to be much more susceptible to the effects of the misleading information than that of middle aged participants.

Conclusion -  These studies suggest that elderly witnesses have poorer general recall and are more susceptible to misleading information.

The reliability of eyewitness recall has been of great concern, considering that in many instances solving the crime is very much dependent on an individual's ability to recall the details of an incident or perpretrator.

The Cognitive Interview Technique - Fisher & Geiselman (1985):

Suggested that this method could be used to retrieve information needed, particularly in terms of getting accurate witness testimony during police questioning.

This method uses 4 techniques in order to retrieve the memory needed:

1) Context Reinstatement (to recreate the context) - The interviewer may try to get the individual to mentally create the environment as well as placing the time of the incident within personal context, such as by asking: what they were doing at the time prior to the incident, what the day or weather was like, whether it was raining or sunny, how they were feeling at the time etc. This taps into the specific environmental cues that were present and may help 'jog' the memory.

2) Change Perspective - The interviewer may ask the individual to recall the incident from a different perspective, such as asking the witness what they think other people may have seen. This may enable the individual to recall something from a different recall route.

The Cognitive Interview Technique - Fisher & Geiselman (1985) (cont.):

3) Reverse Order - The interviewer may ask the individual to recall the incident in a different order to how it occured - a different narrative order. As with 'change perspective', this may enable the individual to recall something from a different recall route.

4) Report Everything - The interviewer may ask the individual to recall every little detail even if they seem unimportant. Irrelevant details may help to trigger more significant ones. Doing this can elicit other memories linked to seemingly insignificant details. 

+) Overall, researchers have found that CI has been useful in increasing the accuracy of EWT.

+) Retrieval cues enhance and improve memory recall.

+) This approach gives individuals time to recall and retrieve information with more accuracy.

+) Milne & Bull (2002) found that when used singularly, the 4 techniques improved recall.

+) The techniques of 'context reinstatement' and 'reporting every detail' seem to be the most effective combination of elements in terms of eliciting accurate recall.

+) Godden & Baddeley (1975) found that memory can be significantly improved when the encoding and recall takes place in an environment not too dissimilar, if not the same as where the incident occured.

+) Most studies show it elicits more information that other types of questioning in both lab and real life situations.

-) However, it seems to elicit more inaccurate information.

-) Geiselman (1999) found that in reviewing cases where the witness was under the age of 6, the recall was not as accurate, maybe because they failed to understant the instructions. This suggests that a different approach would have to be used according to who the information was being retrieved from, and CI isn't the best approach to use in all cases.

-) There's also an ethical issue: using this approach to recall in detail violent, sexual or gruesome events could be too traumatic for the witness concerned.

In order to minimise the amount of inaccurate information given by interviewees in a Cognitive Interview, Fisher (1987) recommends using an 'Enhanced Cognitive Interview' technique.

The Enchance Cognitive Interview technique involves:

• Police actively listening to the witness.
• Distractions being minimised.
• Using open-ended questions.
• Encouraging the use of imagery.
• Avoiding making judgemental comments.

Research into memory has provided us with various techniques that we can use to improve our retention of information. These techniques are based on:

• Orangisation of Information:
  • Mnemonics.
  • Visual Techniques (incl. Method of Loci).

• Encoding & Retrieval Strategies:
  • Encoding Specificity Principle.
  • The Role of Context.
  • The Role of an Individual's State.
• Active Processing:
  • Processing Information on a 'deep level'.

The way we organise information that we wish to remember is central to remembering it effectively.

One of the best known organisational strategies is using mnemonics.

Mnemonics - Using verbal yhmes or visual images to organise information such as processes or events which need to be remembered in order.

Example: Remembering the order of the planets in the solar system by making up a rhyme which uses the first letter of each name of the planet. You 'chunk' the 9 planets into 1 single item (the phrase) rather than into 9 separate items (the 9 planets), which will therefore only take up 1 slot of STM capacity when you recall it.

Some mnemonic techniques are based on visual imagery, including a technique called the method of loci. 

Visual Imagery - Involves linking a visual image to the information that you wish to remember.

Method of Loci - Allows us to remember things (e.g. shopping lists) by visualising a familiar place already stored in the LTM and 'hanging' new information from it.

Example: You're going to the shops and have a shopping list  of 8 things to remember. Remembering the list by rote memory means you need to make 8 seperate entries into your STM, making it hard to remember, but this isnt the best allocation of resources. Now, using the loci method to remember the list:

• 1) Think of a familiar routine which you do in the same order every day, which is easily available to you in your LTM.
• 2) Using your imagination, make each of the items on the shopping list interact with different stages of your routine.

Memory using the loci technique is typically robust: you can recall the information remembered tomorrow, next week, even next month, provided that the interactions are bizarre as this makes them more memorable.

Dual-Coding Theory - Uses the idea that mental images helps learning. A person can expand on learned material from verbal associations and visual imagery.

Example: A person has stored 'dog' as both the word and the image of one. When recalling, they can either retrieve the word or the image, separately or simultaneously.

Bransford & Johnson (1972): Devised an experiment to test this theory:

Method:

• They asked 2 groups of participants to read a long paragraph and remember the main details.
• For one group, the passage was given the title 'Doing the Laundry', whilse the other group weren't given a title.

Findings:

• The group who were given the title performed significantly better on the recall test.

Conclusion: This suggests that understanding the materical and knowing the context significantly improves a person's ability to remember. 

Many memory strategies are based on the encoding specificity principle.

Encoding Specificity Principle - States that when we acquire memories, we encode them with links to the context we were in at the time. Therefore, the context becomes a retrieval cue which can help recall information stored in the LTM.

Tulving & Osler (1968): Carried out a study to illustrate this idea.

Method:

• They gave participants a list of words, each of which was paired with a cue, e.g. 'city-dirty'.
• Participants were then asked to recall the original list, either by free recall or cued recall (they were presented with the cue words and had to remember the word associated with it).

Findings:

• The findings showed that cued recall produced consistently better performance than free recall.

Conclusion: The study shows that retrieval cues can help to improve recall.

Studies show that the context in which learning took place can act as a retrieval cue.

Godden & Baddeley (1975): Carried out a study to look specifically into context-dependent retrieval.

Method:

• They asked divers to learn a list of 40 unrelated words, either on land or under water.
• Later, half the divers recalled the words in their original context whilst the other half recalled in a different context (i.e. those who had learned the list on land recalled under water and vice versa).

Findings: 

• Those who recalled in the same context as the one in which learning had taken place remembered more words.

Smith (1979): Also carried out a study to see if context effects retrieval.

Method:

• Participants were given a list of 80 words to learn whilst sitting in a distinctive basement.
• The next day, he tested some participants in the same basement, some in upstairs rooms and a third group in an upstairs room but these participants were asked to imagine that they were in the original basement room.

Findings:

• Those in the original context recalled the most words, followed by those in the upstairs room who imagined that they were in the original context.
• The worst recall was produced by those in the upstairs room, as they were in a different context.

Conclusion: These studies suggest that context must have been encoded along with the information being remembered, therefore context can act as a retrieval cue.

There is evidence that physiological state or mood can also affect recall.

Goodwin et al (1969) found that heavy drinkers who learn things in a drunken state are more likely to recall what they learnt when in a similar state.

Eich (1980) found the same effect with marijuana.

However, in a meta-study, a review of research into mood, Ucros (1989) found a moderately strong relationship between mood at the learning stage and at the retrieval state. She also found that mood was more likely to affect memories of real-life rather than artificially constructed material, and that adults were more affected by mood dependence than children.

Conclusion: In general, there's less conclusive evidence that mood effects recall.

Craik & Tulving (1975) think that we're more likely to remember material that we have actively processed by interacting with material on a 'deep level'.

They identified 3 levels on which we can take in information:

• Structural - What does it look like?
• Phonological - What does it sound like?
• Semantic - What does it mean?

They argued that taking in information on a structural level involves a very shallow level of processing, resulting in a memory trace that is not very robust.

Deep processing (resulting in good retention) comes from understandng material semantically.

Craik & Tulving (1975): Carried out a study to show this:

Method:

• They gave participants a list of words to which they had to answer questions requiring shallow, medium or deep processing.
• They then gave participants a surprise recall test.

Craik & Tulving (1975) (cont.):

Findings:

• Words associated with deep processing on a sematic level were best remembered.
• Participants didn't know that they were going to be tested, but still performed as well as a control group who made a particular effort to remember the words on the list.

Tyler et al (1979): Questioned the notion of levels of processing. They believed that sematic tasks required more effort & it's the effort required in processing the information which improves recall. 

Method:

• To test this idea, they gave participants 2 sets of anagrams to solve: 'easy' and 'difficult'.
• Participants were later given an unexpected recall test.

Tyler et al (1979) (cont.)

Findings:

• They found that significantly more difficult anagram words were recalled.
• Since all the words were processed at the same level (semantically, therefore all at a deep level), the better recall in the difficult group must have been due to the effort put into processing them and not the depth of processing.

Conclusion: Due to different results between these two studies, it's difficult to dertermine whether meaningful interaction or effort put into processing affects recall.

Nevertheless, most studies into Active Processing show that the more you interact with the material and the more elaborate and organised you make it, the more likely you are to remember it in the long term.