Memory Flashcards
STM and LTM definition
Short term memory - the phase or type of memory responsible for the temporary storage of information
Long term memory- the phase or type of memory responsible for the storage of information
Coding, capacity and duration definition
Coding - process of converting information between different forms eg. Taking an event and turning it into memory. You can code information:
- semantically: what the information means
- acoustically: how information sounds
- visually: how information can be seen
Capacity - how much information the STM can hold at one time
Duration - refers to the length of time that information can be held in STM and LTM
Research into coding
- baddeley
- 4 lists of words
Aim - to find out how information is stored and in which forms depending on if it was entering the LTM or the STM
Method - he split participants into 4 groups:
Group 1: acoustically similar words
Group 2: acoustically dissimilar words
Group 3: semantically similar words
Group 4: semantically dissimilar words
After participants had looked at these words they were asked to recall them at different intervals
results - when participants were asked to recall the words after a short period (using their STM) their recall was worse for acoustically similar words. When asked to recall words after 20 minutes (using their LTM) they did worse with semantically similar
conclusion - STM codes acoustically and LTM codes semantically
Evaluation of research into coding - AO3
- Baddeley
- lists of words
✅
- controlled
- clear difference
❌
- ecological validity
✅
- well controlled as all participants received the same instruction so easy to replicate
- showed a clear difference between the two different memory stores that has withstood the test of time
❌
- lacks ecological validity as the stimuli (the words) were chosen randomly and didn’t have any link to real life . If they did they may have been remembered better.
Research into capacity - AO1
- Miller
- ? +/- 2
- chunking
- he concluded that the capacity of the STM was 7+/- 2 items after extensive research
- he believed it was possible to increase the capacity through chunking
- for example phone numbers are 11 digits which exceeds the 7 +/- 2 item limit however we chunk it : 07828 431 676 so now there are only three items rather than 11 single digits
Evaluation of research into capacity - AO3
✅
- supporting study (Jacobs and digital span)
❌
- individual differences
✅
- Millers study is supported by Jacobs who used serial digit span to measure the capacity of the STM, he gave participants a number/letter to recall and if they got that he added another and so on. He found that the average digit span was 9.3 for numbers but 7.3 for letters. Both support the idea that the STM can hold 7 +/- 2 items.
❌
- it fails to take into account individual differences such as age. Other studies suggest that the capacity of the STM may decline with age. This suggests that Millers study may not be generalisable to all.
Research into duration of STM
- Peterson and Peterson
- syllable and 3 digit number
- recall %?
aim - to investigate the duration of the STM
method - 24 students were tested on 8 separate trials. On each trial the students were given a constant syllable to remember and a 3 digit number. The students had to count backwards from this number until they were told to stop. On each trial they were told to stop after varying periods time ( 3 16,9,12,15 seconds) they were then asked to recall the constant syllable.
results - after 3 second the average recall was around 80 % but after 18 seconds it was 3
conclusion - the shorter the amount of the you have to remember something for the easier it is to recall
Evaluation of research into STM
- Peterson + Peterson
✅
- controlled
❌
- low ecological validity
✅
- highly controlled lab settings
❌
- lacks external validity due to low ecological validity because stimuli has no relevance to everyday life
Research into duration of LTM
- Bahrick et al
- yearbooks
- photo recognition and free recall
aim - investigate the duration of the LTM
method - studied 392 american pp aged between 17 and 74 whose highschool yearbooks were obtained from up or directly from schools. They later tested recall in two methods:
- a photo recognition test consisting of 50 photos, some from the yearbook
- free recall test where pp recalled all the names of their graduating class
results - pp who were tested within 15 years of graduation were 90% accurate in photo recognition and 60% in free recall. After 48 years 70% in photo recognition and 30% in free recall
conclusion - accuracy of LTM decreases with age and accuracy of LTM improves with a stimulus
Evaluation of research into duration of LTM
- Bahrick et al
✅
- ecological validity
❌
- population validity
✅
- high levels of ecological validity as used real life memories
❌
- only used Americans so lacks population validity
Multi-store model - AO1
- cognitive psych
- capacity, duration and coding of stores?
link
- it is a structural model
- info passes from one store to another in a linear way
- rehearsal is needed to pass info from STM to LTM
- each store has its own duration, capacity and coding
sensory memory - codes based on the sense it is linked to, duration is 0.5 - 2 seconds, very high capacity
STM - codes acoustically, duration is 18 seconds without rehearsal, capacity of 7 +/- 2 items
LTM - codes semantically, duration is unlimited, capacity is unlimited
Evaluation of the MSM - AO3
✅
- amnesiacs (Clive Wearing)
- KF supporting study
❌
- over simplified
- kuilik and brown
✅
- when amnesiacs lose their memory they lose EITHER their STM or LTM so this supports the idea that the stores are different. Clive Wearing was an amnesiac he lost most of his LTM but none of his STM
- following a motorcycle accident KF’s LTM was intact however his STM was damaged
❌
- model may be over simplified as KF’s STM was fine for visual but not for verbal. Suggests more than type of STM
- Kuilik + Brown discovered that when something was so traumatic it goes straight into the LTM without rehearsal
Types of LTM - AO1
- Tulving
- 3 memory stores
- episodic: knowledge of personal events, can be explained verbally (declarative)
eg. First day at school, friends wedding - semantic: knowledge of the world
eg. Purpose of money, who the prime minister is - procedural: knowledge of how to do things, difficult to explain verbally (non-declarative)
eg. how to ride a bike, how to make a cake
Evaluation of types of LTM - AO3
✅
- Doctor S
- ewart et all study of post traumatic amnesia
❌
- cohen 2 types
✅
- Doctor S lost his episodic memory after a fall and the last 25 years was a blank. However at the hospital after asking for a brain scan he correctly diagnosed himself. This shows that his semantic memory is still intact
- ewart et al studied 16 patients with post traumatic amnesia. Their episodic memory was poor but their procedural was good
❌
- Cohen studied LTM and found there was only 2 stores (declarative and non-declarative) instead of 3 like Tulving suggested
Working memory model
- baddeley + hitch
- STM
- four stores
link
- structural model by Baddeley and Hitch
- focuses on STM
- divides STM into 4 stores: central executive, phonological loop, Visuo-spatial sketchpad, episodic buffer
central executive - has a supervisory role as it supervises, monitors and coordinates information to and from the other parts of the slave system. Very limited capacity however can process information in all forms
Phonological loop - deals with auditory information and preserves the order in which it arrives. Split into two subsections:
- phonological store: stores the words you hear. Limited capacity
- articulatory process: (inner voice) allows maintenance rehearsal as you can say things over and over in your head. Used to rehearse verbal information from phonological store.
Visuo-spatial sketchpad - stores visual and spatial information for example when you picture something in your head. Limited capacity of 3/4 items. Split into 2 subsections:
- visual cache: information about visual colour
- inner scribe: spatial and arrangement information
episodic buffer - added on later, general temporary store of information, integrates visual, spatial and verbal information, maintains sense of time sequencing and records events, limited capacity of 4 chunks, links working memory to LTM
Evaluation of the working memory model - AO3
✅
- supporting case study KF
- supporting study Baddeley et al dual task performance
❌
- lack of clarity over central executive
✅
- it is supported by the case study of KF who suffered brain damage. He had poor STM abaility for verbal information but was fine with visual information. Suggests his phonological store had been damaged
- Baddeley et al did a study that showed participants had more difficulty doing two visual tasks than doing both a visual and a verbal task at the same time. This suggests that the difficulty is increased as both visual tasks compete for the same slave system
❌
- the central executive is unsatisfactory and doesn’t explain anything. Baddeley said the central executive is the most important but least understood. The WMM hasn’t been fully explained.
Explanations for forgetting- Interference theory
- Interference, proactive and retroactive
- definition of all
- ceraso research: competition of response, unlearning theory
Interference - forgetting occurs when there are two competing memories, when two memories are similar in nature they can become confused to the point one is forgotten
Retroactive interference - when a new memory interferes with the recall of an old memory, the old memory is forgotten
Proactive interference - when an old memory interferes with the recall
ceraso research:
Competition of response - older memory is not actually forgotten just misplaced. Newer memory held in spot where older memory was
Unlearning theory - new memory actually replaces older memory
Evaluation of interference theory - AO3
✅
- underwood and post man 2 lists of words
- underwood word list forgetting
❌
- doesn’t reflect real life memory Baddeley
- only explain temporary forgetting
✅
-RETROCTIVE: underwood and postman. 2 groups given paired words. Group 2 given a second list where first word of each pair was the same as the first list. Participants asked to recall first list. Recall was worse for the second group as new learning interfered with old learning
-PROACTIVE: Underwood found evidence for proactive interference by reviewing studies on word list forgetting. Participants who learned 15 or more lists recalled only 15% of the last list, compared to 80% recall for just one list. This shows that earlier learning affects recall of later material, illustrating proactive interference.
❌
- A limitation of this theory is that research supporting it doesn’t reflect real-life memory recall timelines. Baddeley noted that most studies involved immediate recall after learning, while in everyday life, we often recall memories weeks or months later. This suggests the theory may not apply to everyday scenarios, questioning its validity.
- A limitation of interference theory is that it may only explain temporary forgetting. It’s suggested that with the right cue, we can often retrieve information from long-term memory. This limits the theory, as it doesn’t account for how cues can aid recall.
Explanations for forgetting - retrieval failure
- three types of cues: context, state, category
- tulving and thomsons encoding specificity principle
- according to retrieval failure theory, nothing is ever forgotten, we just lack the cues needed to
get the infomation - There are three types of cues: context, State and category dependent
- Tulving and Thomson proposed the encoding specifity principle
Encoding specificity principle - Tulung + Thomson proposed that memory is most effective if information that was present at encoding is also available at time of retrieval. This is evidence of cues that have been explicitly / implicitly encoded at time of leaning and have a meaningful link to learning material
Cues -
context - being in different place at recall, to that of learning may make recall difficult
state - being in different mood, state of arousal at recall to that of learning may hinder recall
Category - lack of organisation (depending on how we ‘file’ our cues) might mean we cannot access the original
Evaluation of retrieval failiure
✅Abernathy testing students
✅Goodwin et al drunk students.
❌cues not explaining all memory
✅ supporting study - Abernathy tested students every week and found that recall was best in teaching room with teacher present
✅ supporting study - Goodwin et al gave 48 medical students alcohol and information to learn. information was best remembered when they next got drunk again.
❌ cues may not explain all types of memory for example procedural
factors affecting the accuracy of eye witness testimony - misleading information: leading questions
- misleading information
- leading information
- why do leading questions affect EWT: response bias and loftus broken glass experiment
misleading information - incorrect information given to an eyewitness, usually after the event It can take many forms such as leading questions and post event discussion
Leading question - a question which, because of the way it is phrased, suggests a certain answer
why do leading questions affect EWT
response bias explanation suggests the wording or a question nas no effect on memories but instead influences how they answer loftus did a second experiment where participants who originally heard smasned were more likely to recall having seen broken glass when there wasn’t any insinuating the memory has been altered
Research on leading questions - loftus + palmer
- traffic accidents with different verbs
- fasted verb and slowest verb?
- can they affect memory?
- low ______ validity
Aim - to see if the speed estimates would be influenced by the wording of the question asked eg contacted Vs smashed
method - 45 participants were shown 7 films of traffic accidents and asked:
how fast were the cars going when they _______ each other? the verb was replaced with either smashed, collided, bumped, hit or contacted
Results -
- contacted → 31.8 kph
- hit → 34 kph
- bumped → 38.1kph
- Collided → 39.2 kph
- Smashed → 40.8 kph
Conclusion- leading questions can affect a persons memory of an event and when police are questioning they should avoid using leading questions
Evaluation -
❌ low ecological validity
❌ low population validity
Factors affecting the accuracy of eye witnesses testimonies - misleading information: post event discussion
- memory conformity
- repeat questioning
- memory contamination
post event discussion - occurs when there is more than one witness to an event. witnesses may discuss what they have seen with co-witnesses this may influence the accuracy of each witness’s recall memory conformity - where people are influenced by another persons report this may introduce mistakes, leading to inaccurate recall
repeat questioning - each time an eyewitness is interviewed, there is the possibility that the comment from the interviewer gets incorporated into their recall
why does post event discussion affect EWT
-one explanation is memory contamination. when co-witnesses discuss their testimonies they may become altered/distorted as they combine misinformation from other witnesses memories. -Another explanation is memory conformity. witnesses go along with each other to win social approval or because they believe others are correct and they are wrong
Research on post event discussion - gabbert et al
- studied participants in pairs
- watched video from different points of view
- had a discussion afterwards
method- studied participants in pairs. each participant watched a video of the same crime but filmed from different point of views. This meant that each participant could see elements in the event the other couldn’t. Participants then discussed what they had seen before completing a test of recall
Results - researchers found that 71% of the participants recalled parts of the event they didn’t see in the video but instead picked in the discussion in the group where there was no discussion the figure was 0%. this is evidence of memory confomity
