Memory Flashcards
(15 cards)
Multi-store model
Atkinson and Shiffrin (1968) proposed the multi-store model (MSM) of memory, which has three components: sensory register (SR), short-term memory (STM) and long-term memory (LTM). Each of these stores has a different capacity, duration and coding.
Sensory register - Capacity = unknown, but very large! Duration = Very limited (1-2 secs). Coding = Raw/unprocessed information (from all 5 senses).
Short-term memory - Capacity = Limited (7 +/-2 ‘chunks’ of information) (Miller, 1956). Duration = Limited (20 secs) (Peterson and Peterson, 1959). Coding = Acoustic (sound).
Long-term memory - Capacity = Unlimited. Duration = Lifetime/Years (Bahrick, 1975). Coding = Semantic (meaning).
Capacity of STM
Miller (1956) and Jacobs (1887)
Aim:
- To investigate the capacity of STM.
Procedure:
- Jacobs (1887) examined the capacity of the STM using a digit span test. His study used 443 female students who were required to repeat back a string of numbers or letters.
- Miller (1956) published an article entitled ‘The Magical Number Seven, Plus or Minus Two’ in which he reviewed existing research into STM.
Findings:
- On average, Jacobs’ ups could recall 7.3 letters and 9.3 words.
- Miller’s review of STM research led him to state that we can hold seven ‘items’ or ‘chunks’ of information in STM, plus or minus two.
Conclusion:
- STM has limited capacity of 7 +/- 2 chunked letters, numbers or words.
Duration of STM
Peterson and Peterson (1959)
Aim:
-To investigate the duration of STM.
Procedure:
- Investigated the duration of STM using a sample of 24 psychology students.
- The students had to recall three-digit trigrams at different intervals *3, 6, 9, 12, 15 and 18 seconds).
- To prevent rehearsal, they had to count backwards in threes or fours from a specific number, until they were asked to recall the letters.
Findings:
- After 3 seconds, around 80% of the trigrams were correctly recalled, whereas at 18 seconds only 10% were correctly recalled.
Conclusion:
- STM has a limited duration of approximately 18 seconds.
- Furthermore, the results show that if we are unable to rehearse information, it will not be passed o=to LTM, providing further support for the multi-store model and the idea of discrete components.
Duration of LTM
Barrack (1975)
Aim:
- To investigate the duration of LTM.
Procedure:
- Investigated the duration of LTM using 392 American university graduates.
- Pps were asked to match the names of former classmates with photographs from their high-school yearbook.
Findings:
- 60% correct recall after 47 years.
Conclusion:
- People can remember certain types of information, such as names and faces, for almost a lifetime. These results support the multi-storey model and the idea that our LTM has a lifetime durations of at least 47 years and is semantically encoded.
Episodic, semantic and procedural LTM
LTM is a ‘permanent’ store that holds unlimited amounts of information for long periods of time. There are different types of LTM: episodic, semantic and procedural.
Episodic memory - a personal memory with 3 specific elements: details of the event, the context and the emotions experienced. Episodic memories are associated with a part of the brain called the hippocampus.
Semantic memory - our knowledge of facts, concepts and meaning, e.g. knowing that London is the capital of England is a semantic memory. Semantic memories are associated with a part of the brain known as the temporal lobe.
Procedural memory - memory of performed motor tasks/skills, e.g. swimming and writing. Procedural memories are acquired through repetition and practice, and are associated with the cerebellum and motor cortex.
The working memory model
Baddeley and Hitch (1974)
The working memory model (WMM) can be used to explain some of the research findings that couldn’t be explained by the multi-store model.
The WMM is a multi-component STM system, consisting of a central executive, phonological loop and visa-spatial sketchpad.
- Central executive - boss of WMM, directs attention.
- Phonological loop - made up of: Articulatory control process (sub vocal repetition); and Phonological store (storage space, limited capacity).
- Visuo-spatial sketchpad - made up on: Inner scribe (manipulates mental images); and Visual cache (storage space, limited capacity).
- Episodic buffer - binds and integrates information, and maintains a sense of time, so that events occur in a continuing sequence.
Dual-task studies
Baddeley and Hitch (1976)
Aim:
- To test the theory that auditory memory and visa-spatial memory are stored separately within the STM.
Procedure:
- Pps complete two tasks at the same time.
- Condition 1: pps complete two acoustic based tasks.
- Condition 2: pps complete one acoustic and one visual task.
Findings:
- When both tasks require the pps to use their phonological loop, their ability to perform the tasks is impaired. However, when one of the tasks uses the visa-spatial sketchpad (copying a drawing), then performance is not impaired.
Conclusion:
- This provides evidence that auditory memory and visa-spatial memory are stored separately in STM.
Patient KF
Shallice and Warrington (1975)
Patient KF (case study) was injured in a motorbike accident. Following his accident, Patient KF was able to recall stored information from his LTM; however, he had issues with his STM. He was able to remember visual images, including faces, but was unable to remember sounds (acoustic information).
Implications for the multi-store model - the fact that KF could remember visual images but not sounds, and access his LTM without having to first go through his STM lends support to the WMM theory of STM as an active and complex store either two slave systems - the visuospatial sketchpad and the phonological loop - and also contradicts the STM model flow diagram that shows all information entering LTM having to pass through STM.
Forgetting: Proactive interference, retroactive interference, and retrieval failure
Forgetting = failure to remember something. It can occur due to interference or retrieval failure.
Proactive interference - occurs when old information stored in LTM interferes with the learning of new information. This usually occurs when the new information is similar to the old information. An everyday example of proactive interference is when you are trying to remember a new mobile number and your memory of your old number disrupts your attempts to remember this new information.
Retroactive interference - occurs when the learning of new information interferes with the recall of old information from LTM, e.g. once you have learned a new mobile number, it is often very difficult to recall your old number.
Retrieval failure - an explanation for forgetting from LTM. It refers to difficulties in recall that are due to the absence of the correct retrieval cues or triggers.
Forgetting - interference theory
Baddeley and Hitch (1977)
Aim:
- To investigate retroactive interference in everyday memory.
Procedure:
- The sample included rugby union players who had played every match in the seasons and players who had missed some games due to injury. The length of time from the start to the end of the season was the same for all players, and players were asked to recall the names of the teams they had played against earlier in the season.
Findings:
- The players who had played the most games forgot proportionately more games than those who had played fewer games due to injury.
Conclusion:
- Baddeley and Hitch concluded that this was the result of retroactive interference, as the learning of new information (new team names) interfered with the memory of old information (earlier team names).
Forgetting - retrieval failure
Godden and Baddeley (1975)
Aim:
- To test the theory of retrieval failure due to absence of environmental cues.
Procedure:
- 18 scuba divers were sampled.
- They wither learned words on land or underwater and then recalled words either on land or underwater (resulting in four possible conditions).
Findings:
- The words learned underwater were better recalled underwater and words learned on land were better recalled on land.
Conclusion:
- There was retrieval failure when in a different environment from that in which the words were learned, due to an absence of environmental cues.
Misleading questions
Loftus and Palmer (1974)
Aim:
- To investigate the effect of leading questions introduced after an event, on eyewitness memory of that event.
Procedure:
- 45 American students were divided into 5 groups with 9 pps in each.
- Each pp watched 7 videos of car accidents.
- Asked leading questions regarding their estimates of the car speed just before the impact; different verbs were used, e.g. ‘smashed’, ‘collided’, ‘bumped’, ‘hit’, ‘contacted’.
Findings:
- The verb ‘smashed’ generated an average speed of 40.5 mph.
- The verb ‘contacted’ generated an average speed of 31.8 mph.
Post-event discussion
Gabbert et al (2003)
Aim:
- To investigate whether or not a discussion of an event after it had occurred could affect someone’s memory of said event.
Procedure:
- 60 students from Aberdeen and 60 older adults.
- Watched a video of girl stealing money from a wallet but from different visual angles, giving some clearer view of the theft than others. Pps discussed video before answering questions.
Findings:
- 71% of witnesses recalled information they had not seen.
- 60% said they saw the girl stealing money when they hadn’t.
Conclusion:
- Pps’ memories can be altered significantly by holding a discussion after the event. This has implications for eyewitness testimony where there are more than one witness.
Anxiety
Johnson and Scott (1976)
Aim:
- To investigate the effect of a weapon on eyewitness testimony accuracy.
Procedure:
- Pen/knife study: Pps waited in a reception area and were exposed to either:
1) a heated argument in the next room, a crash of equipment and then a man emerged holding a paperknife.
2) A disagreement about lab equipment in the next room and then a man left holding a pen.
- Pps had to identify the man from 50 photos.
Findings:
- Those in the pen condition were correct 49% of the time.
- Those in the knife condition were correct 33% of the time.
Conclusion:
- Anxiety decreased the effectiveness of eyewitness testimony, as pps were focusing on the knife rather than the man’s face. This has been named the ‘weapon focus’ phenomenon.
The cognitive interview
Geiselman et al. (1985) developed the cognitive interview, identifying 4 key principles that they believed would enhance the recall:
CONTEXT REINSTATEMENT (CR) - a person mentally recalls the context of the event, e.g. a person might recall the time of day, the weather, who they were with, or even their feelings. These details can then act as a trigger, to help the person recall more information.
REPORT EVERYTHING (RE) - a person recalls every detail they can remember, even those that may seem trivial.
RECALL FROM CHANGED PERSPECTIVE (CP) - a person considers the event from someone else’s point of view, e.g. they might consider what the offender saw.
RECALL IN REVERSE ORDER 9RO) - a person recalls the events in reverse chronological order.
