Memory

Memory

1. Working Memory Model (WMM)

   • Originally designed by Baddeley and Hitch (1974), the Working Memory Model (WMM) is an alternative to the multi-store model of memory (MSM), which they saw as underestimating the complexities of the STM
   • How short-term memory works:It consists of several different components Each component has a particular function – includes not only storage but manipulation and analysis of information It is an active system which allows us to work things through. Two tasks can be carried out simultaneously in STM if they are being dealt with by different parts of the memory system
   • Central executive: Key component Supervises and coordinates information to and from the slave systems Very limited capacity It decides what needs to be done and when.
   • Phonological loop
     • Articulatory loop Active rehearsal system where words are maintained by subvocal repetition. Repeats info from phonological store Inner voice.
     • Phonological store Passive storage system Holds spoken information Inner ear.
   • Visuo- spatial sketchpad
     • Inner scribe Active rehearsal system Processes spatial and movement information.
     • Visual cache Passive visual store Stores info about visual form and colour.
   • Episodic buffer: Added in 2000 as the model needed a more general store. Slave systems deal with specific types of information. Central executive has no storage capacity Episodic Buffer is extra storage system but with limited capacity. it records events that happen, and sends information to the LTM.
   • Evaluation: evidence from brain damaged patients: Key evidence for the WMM comes from case studies of individuals who have suffered from serious brain damage. The process of brain injury is traumatic, which may change the behaviour of a person making them perform worse on certain tasks. these individuals have difficulty paying attention and therefore underperform in some tasks.
   • Evaluation: evidence from brain damaged patients: studies on a man called KF whose short term forgetting of auditory information was much greater than that of visual stimuli. In addition his auditory problems were limited to verbal material such as letters and digits but not meaningful sounds e.g. a phone ringing. his brain damage seemed to be restricted to his phonological loop.

2. Eyewitness testimony

   • Post event discussion: Repeat interviewing:Each time the witness is interviewed comments from the interviewer could become incorporated into the recollection of events. Interviewer could use leading questions to alter the individuals memory especially when interviewing children.
   • Eyewitness testimony: The evidence provided in court by a person who witnessed a crime, with a view to identifying the perpetrator of the crime
   • Loftus and Palmer leading questions
     • Evaluation: Lacks ecological validity as participants only watched a video clip of the accident. As it was artificial, participants may be less motivated to remember the incident. In real life witnessing a crime is more meaningful and important.
     • Experiment 2: Procedure – A leading question may bias a pt’s response or cause info to be altered before is stored. A new set of pts were divided into 3 groups and shown a film of a car accident lasting 1 minute, and asked questions about speed. The pts were asked to return 1week later, they were asked a series of 10 questions about the accident, including a critical question, ‘Did you see any broken glass?’ There wasn’t broken glass in the film but, those who thought the car was travelling faster might be more likely to think that there would be broken glass.
       • Results – Pts who had estimated a higher speed were more likely to have said they had seen broken glass, as indicated by the findings in the table.
     • Evaluation: type of method used (lab) and its practical applications.
     • Aim - To investigate whether leading questions affects the accuracy of EWT after an event.
     • Experiment 1: Procedure – 45 Pts were shown 7 films of different car accidents. After each film the pts were given a questionnaire asking them to describe the accident then answer a series of specific questions about it. One crucial question concerned the speed of the car on impact. Group 1 got asked ‘How fast were the cars going when they hit each other?’ Other groups were asked the same question but the verb was changed to either ‘smashed’ ‘bumped’, ‘collided’, or ‘contacted’. This critical question was a leading question as it suggested the answer that a pt would give, therefore encouraging them to provide a certain response.
       • Results - The verb used significantly affected speed estimates- Contacted=31.8MPH, Hit=34.0MPH, Bumped=38.1MPH, Collided=39.3MPH, Smashed=40.8MPH Therefore smashed’ produced the highest estimate and ‘contacted’ produced the lowest estimate.
     • Evaluation: Demand characteristics The eye witnesses knew they were taking part in an experiment, may not have taken the task as seriously as if it was real life. Demand characteristics could have effected the pts behaviour, they may have worked out the aim of the experiment and estimated faster speeds in the ‘smashed’ group on purpose. This could make results less valid as they may not be a realistic measure of the effect of misleading info on EWT, so cant generalise findings to real life EWT accounts.
   • Post event discussion: Conformity effect: Co-witnesses may reach a consensus view of what actually happened. Pts were in pairs each partner watched a different video of the same event so they viewed unique items. 71% who had discussed the event went in to mistakenly recall items acquired during the discussion.
   • Evaluation: Real world applications: Criminal justice system relies on eyewitness identification for investigating and prosecuting crimes. Mistaken eyewitness identification was the largest factor contributing to the conviction of innocent people.
   • Evaluation: Individual differences: Age differences, An eyewitness typically acquires info from 2 sources observing the event and from subsequent suggestions. Compared to younger people elderly people have trouble remembering the source of the info. They become more prone to the effect of misleading info when giving testimony.
   • Accuracy of eyewitness testimony: anxiety
     • Johnson and Scott
       • Anxiety reduces the accuracy of recall. The view of a weapon in a criminals hand distracts attention (as anxiety is created) form other features which reduces the accuracy of identification.
       • Findings: 49% in identifying the man in the pen condition compared to 33% accuracy in the knife condition. Lotus et al showed anxiety focuses attention on central features of the crime. Researchers monitors the pt's eye movement and found that the presence of a weapon caused attention to be drawn to the weapon and away from the persons face.
       • Procedure: Pts sat in a waiting room where they heard an argument in an adjoining room and then saw a man run through the room either carrying a pen covered in grease or a knife covered in blood. People were later asked to identify the man.
     • Yerkes dodson effect above.
     • Anxiety can improve accuracy: reasearch shows evidence of enhanced recall when they questioned 58 real witnesses to bank robberies in Sweden. They were either victims of bystanders high and low anxiety levels would be shown. Interviews took place 4-15 weeks after. All showed good memories for details of the robbery itself (75% accurate recall) witnesses who were more anxious has the best recall (the victims) so anxiety doesnt reduce accuracy of recall.
     • Evaluation: real life vs lab studies: It was a study of anxiety in context of a real life crime. lab studies may not create real anxiety that would be created in an actual crime.
     • Evaluation: surprise not anxiety: pts watch a thief enter a hairdressing salon carrying scissors (high threat, low surprise) a handgun (high threat, High surprise), a wallet (low threat, low surprise) or a whole raw chicken (low threat, high surprise). Identification was least accurate in the high surprise conditions rather than high threat. weapon focus affect is based on surprise.

3. Explanations for forgetting

   • Interference theory
     • An explanation for forgetting in terms of one memory disrupting the ability to recall another. More likely when 2 memories are similar.
     • Proactive interference (pro=forward) occurs when you cant learn a new task because an old task that had been learnt. When what we already know interferes with what we are currently learning – where old memories disrupt new memories.
     • Retroactive interference (retro=backward) occurs when you forget a previously learnt task due to the learning of a new task. Later learning interferes with earlier learning - where new memories disrupt old memories.
     • Underwood and Postman
       • Aim: To investigate how retroactive interference affects learning. So to investigate whether info you have recently received interferes with the ability to recall something you learned earlier.
       • Method: lab experiment
       • Procedure: Pts were split into 2 groups. Both groups had to remember a list of paired words e.g. cat-tree, jelly-moss, book-tractor. The experimental group also had to learn another list of words where the second paired word if different – e.g. cat–glass, jelly-time, book–revolver. The control group were not given the 2nd list. All pts were asked to recall the words on the first list.
       • Results: The recall of the control group was more accurate than that of the experimental group.
       • Conclusion: This suggests that learning items in the second list interfered with pts’ ability to recall the list. This is an example of retroactive interference
     • Evauation: It’s artificial. Lab experiments e.g. in the Postman study it required groups to remember a list of paired words e.g. cat – tree. But, in everyday life the information we need to recall is different, e.g. people’s faces, their birthdays, the ingredients of a pizza. So artificial lab studies lack mundane realism and are low in ecological validity. Therefore, it means we cant generalise the findings from such studies to everyday life as there may well be other factors that influence forgetting.
     • Evaluation: Real world application. Is interference a better explanation for forgetting than the passage of time. They asked rugby players to try to remember the names of the teams they had played so far in that season, week by week. Most players had missed games, for some the ‘last team’ they played might have been 2+ weeks ago. The results showed that accurate recall didnt depend on how long ago the matches took place. It was also found that the number of games they played in the meantime was also influential. So if a player’s recall of a team from 3 weeks ago was better if they had played no matches since then. Therefore, this study shows that interference explanations can apply to at least some everyday situations.
   • Retrieval failure
     • Retrieval failure = A form of forgetting. It occurs when we don’t have the necessary cues to access memory. The memory is available but not accessible unless a suitable cue is provided.
     • Cue = A ‘trigger’ of information that allows access to a memory
     • Type of cue
       • Encoding: Memory is most effective if info that was present at encoding is also available at the time of retrieval. Also states cue don’t have to be exactl but the closer the cue is to the original item, the more useful it will be.
         • Tulving and Pearlstone
           • Pts had to learn 48 words in 12 categories. There were 2 recall conditions. Either 1. recalling as amany words as they could or 2. they were given cues (category name). Resiults: 1. 40% recall, 2. 60% recall. Cues allow us to access memories.
       • State Form of Cue-dependent forgetting where recall occurs in a different internal setting to when info was encoded. So the mental state youre in at the time of learning can also act as a cue. E.g. learning a phone number when drunk but not being able to remember it when sober
         • Goodwin et al
           • Asked male pts to remember words drunk or sober (3 times the limit in the UK) they were asked to recall the words after 24 hours. Results showed info learnt when drunk is more available when in the same state later.
       • Context-Form of cue dependent failure where recall occurs in a different external setting or environment, e.g. getting fewer marks on a test sat in a hall than when taken in the usual classroom.
         • Godden and Baddeley
           • Investigated contextual cues. Scuba divers were pts they were tested on land or in water. 4 experimental conditions. Results showed recall was higher when in the same condition e.g. learning on land and recall on land.
     • Evaluation: The danger of circulatory, Claims: relationship between encoding cues and later retrieval is a correlation not a cause. Cues dont cause retrieval theyre just associated with it. others argue the encoding specificity principle (ESP) is impossible to test because its circular. Stimulus leads to retrieval of a memory then it must have been encoded in memory. If it doesnt lead to retrieval then according to the ESP its not been encoded. But its impossible to test an item if it hasnt been encoded so it cant be proved.
     • P–Research shows forgetting is due to the absence of cues. E – pts were given 5 lists of 24 words, each list organised into 6 categories. E.g. hut, cottage, tent, hotel, cliff, river, hill, volcano. Categories weren’t explicit, it was presumed that they would be obvious to pts. Recall 70% for the first list but this fell as pts were given each additional list to learn, presumably due to interference. E – However, at the end they were given a cued recall test – they were told the names of the categories as a clue. Recall rose again to about 70%. L – Therefore, this shows info is available but cant be retrieved this shows retrieval failure is a more important explanation of forgetting than interference.

4. Cognitive interview Geiselman et al

   • 4 stages:
     • 1. Context reinstatement (CR): Recall image of the scene, the weather, what you were feeling.
       • 2. Report everything (RE): Report every detail you can even if they seem irrelevant or trivial.
         • 3. Recall in reverse or a different order (RO): Describe the event from memorable point.
           • 4. Recall from a changed perspective: Describe the event as it would have been seen from different viewpoints.
   • Additional techniques: Minimising distractions. Asking the witness to speak slowly. Adapting the language used. Reducing anxiety. Avoiding judgemental/personal comments.
   • Evaluation: quantity vs quality: Its meant to enhance quantity without compromising the quality. Research shows an 81% increase of correct info but a 61% increase of incorrect info when enhanced CI was compared to the standard interview. Meaning police need to treat all info collected from CIs with caution. It doesnt guarantee accuracy.
   • Evaluation: effectiveness of the CI: A meta-analysis of 53 studies found an increase of 34% in correct info given in the CI compared to the standard police interview. The effectiveness may be due to some individual elements rather then the whole thing. children were interviewed using 1 technique from the CI the control group were told to 'try again' recall across the 4 components was similar and no different from the control group. Pts interviews using report everything and mental reinstatement caused higher recall.

5. Memory: The process in which we retain information about past events.

6. Multi Store Memory (MSM) Atkinson and Shiffrin

   • Coding (Encoding): The way that info is changed so that it can be stored in a memory store. Environmental stimuli enters the brain and then is stored in various forms.
   • 3 unitary stores: sensory memory, short term memory (STM) and long term memory (LTM)
     • Sensory Memory: First is the SM its constantly receiving information, either visually, auditorily or haptically. But most of this information actually receives no attention and stays in the sensory memory until it decays (taking a matter of milliseconds). If a person is focusing on a piece of information, then instead of decaying it will be directly transferred to the STM.
     • Short Term Memory: When in the STM, information is very 'fragile' and likely to be displaced if its not rehearsed. The average duration for a piece of information in the STM is around 20 seconds and the amount of information that can be held is 7+/-2 items. If the information is rehearsed and payed attention too, then the information will be transferred to the LTM.
     • Long term memory: has a potentially unlimited capacity and the duration of which a piece of information can be held in the LTM is unlimited also.
   • Capacity: A measure of how much information can be stored in the memory.
   • Duration: How long a piece of information can stay in your memory before it is no longer available
   • Haptically: By touch. - Acoustically: By sound. - Semantically: By meaning. - Visually: By sight.
   • Attention: Information is transferred from one store to another. You pay attention to pass information from the sensory store to the STM
   • Forgetting: Memory traces in STM are fragile and can be lost within 30 seconds, through displacement or decay, unless they are repeated (rehearsed). Memory in the LTM is lost through decay, retrieval failure or interference.
   • Retrieval: The process of getting info from the LTM involves the information passing it back through the STM so its available for use.
   • Maintenance rehearsal: Repetition keeps info in the STM but eventually will create a LTM. Atkinson and Sheffrin proposed a direct link between rehearsal in STM and the strength of the LTM.
   • Evaluation: pts were given a list of 50 words that they needed to memorize in a given amount of time. This experiment found that there was a 'recency effect' where the pts remembered the most recent words that they had read because they had not yet been displaced from their STM, they also found that there was a 'primary effect' where the pts remembered the first words on the list because they had been rehearsed more and thus transferred into their LTM. These findings support the MSM because it shows that there are differences between the STM and the LTM and that they are 2 separate, unitary memory stores.
   • Evaluation: The MSM oversimplifies the memory structures and processes. The MSM suggests that the STM and the LTM are 2 different unitary stores which operate in a single, uniform fashion. But research opposes this. Someone known as 'KF' suffered from brain damage which resulted in them having difficulty processing verbal information in their STM. However, KF's ability to process visual information was completely normal. This suggests that the STM is a non-unitary store with different parts dedicated to processing different types of information (haptic, visual, auditory).
   • Evaluation: Lab studies on capacity, duration and coding support the existence of separate stores. Studies using brain scanning techniques have also demonstrated a difference between STM and LTM, The prefrontal cortex is active in STM tasks but not LTM ones and found the hippocampus is active in LTM tasks.

7. Types of long term memory

   • Episodic memory: Personal memories of events, e.g. what you did yesterday or a teavher you liked. This kind of memory includes contextual details plus emotional one.
   • Procedural memory: memory of how to do things e.g. riding a bike or learning how to read. Such memories are automatic as a result of repeated practise.
   • Semantic memory: Shared memories for facts and knowledge. These memories may be concrete, e.g. knowing that ice is made of water, or abstract such as mathematical knowledge.
   • Eavaluation: real life applications. Being able to identify different aspects of LTM allows psychologists to target certain kinds of memory in order to better people’s lives. evidence shows that episodic memories could be improved in older people who had a mild cognitive impairment. The trained pts performed better on a test of episodic memory after training than a control group. Episodic memory is the type of memory most often affected by mild cognitive impairment, which highlights the benefit of being able to distinguish between types of LTM.
   • Evaluation: Theres clinical evidence from people with brain-damage. Several cases of patients who have suffered brain damage to their hippocampus & have memory deficits: Clive Wearing and HM Their memory loss tends to be selective. Episodic memory in both of these men was severely impaired as a consequence of amnesia. They had difficulty recalling events that had happened from their pasts. But, their semantic memories were relatively unaffected. E.g. they still knew the meaning of words. So HM wouldn't be able to recall stroking a dog half an hour earlier and couldn't remember owning one in the past, but he would never need the concept of ‘dog’ explained to him over and over again. Their procedural memories were also intact. They both knew how to tie their shoelaces, how to walk and speak. In Clive Wearing’s case (he was a professional musician), how to read music, sing and play piano.
   • Evaluation: Neuroimaging Evidence. There's evidence from brain scan studies that different types of memory are stored in different parts of the brain. Pts were asked to perform various tasks while their brains were scanned using a PET scanner. E - They found that episodic and semantic were both recalled from an area of the brain- the prefrontal cortex. This area is divided into 2 areas, one on each side of the brain. The left prefrontal cortex was involved in recalling semantic memories. Episodic memories were recalled from the right prefrontal cortex. Procedural memories, however, were recalled from the cerebellum and the basal ganglia.

8. Short term and long term memory

   • Evaluation: Coding: LTM might not have been tested. STM was tested by asking pts to recall a word list immediately after hearing it. LTM was tested by waiting 20 mins, its questionable if thats testing LTM.
   • Evaluation- capacity: The size of the chunk matters: Research showed that people had a shorter memory span for larger chunks, e.g. 8 word phrases, than similar chunks e.g. one syllable words.
   • Evaluation: The STM isnt the same for everyone:research shows capacity increases with age. 8 year olds could remember 6.6 digits, 19 year olds could remember 8.6 digits. Could be due to gradual increase in brain capacity people may have developed strategies as they got older to remember info by chunking etc.
   • Evaluation: Duration: Testing STM is artificial: memorising syllables doesnt reflect everyday life where we are trying to remember is meaningful. Although it does have some relevance when comapred to remembering phone numbers or post codes.
   • Evaluation: Duration: Forgetting things could be due to displacement rather than decay.

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