Memory Flashcards
The multi-store model of memory (definition)
Atkinson and Sherif (1968) developed the multi-store model of memory (MSM), which describes flow between 3 permanent storage systems of memory: the sensory register, short-term memory and long-term memory
Multi-store model of memory
-sensory register
Duration: 0.5 seconds
Encoding: 5 senses
Capacity: Unlimited
Multi-store model of memory
-Short-term memory
Duration: 18-30 seconds
Encoding: Acoustic
Capacity: 5-9 things (rule of 7)
Multi-store model of memory
-Long-term memory
Duration: Unlimited
Encoding: Semantic
Capacity: Unlimited
The working model of memory
Baddeley and Hitch (1974) developed the working memory model as a new approach to understand how short-term memory works
The WMM includes the central executive, phonological loop, visuo-spatial sketchpad and the episodic buffer
WMM components
Phonological loop
-Consists of 2 parts; phonological store= holds the words you hear for 1.5 to 2 seconds, articulatory process= to rehearse verbal information from the phonological store -> these delay in 1-2 seconds
-Auditory processes
-Capacity: Limited
Visuo-spatial sketchpad
-Splits into 2 parts; visual cache= stores information about visual items, inner scribe= stores arrangements of objects in the visual field
-Acoustic, spatial and verbal information
-Capacity: Limited
Central executive
-Supervises and co-ordinates a number of subsidiary systems or ‘slave systems’
-Capacity: Limited
-Encoding: Modality free
Episodic buffer
-Added to the WMM in 2000 by Baddeley
-Capacity: Limited
-Combines into one single memory
Long term memory - Procedural memory
-Is a part of the long-term memory that is responsible for knowing how to do things i.e. memory of motor skills
-It is unconscious (automatic)
-Examples: riding a bike, tying a shoe lace
Long term memory - Semantic memory
-Is a part of the long-term memory responsible for storing information about the world (factual information)
-Examples: ‘Knowing’ that London is the capital of England
Long term memory - Episodic memory
-A part of the long-term memory responsible for storing information about events (episodes) that we have experienced in our lives
-These are ‘time stamped events’
-Examples: Attending a friends birthday or first day at school
Types of LTM
-Implicit and explicit LTM
-Implicit LTM -> Previous experiences aid the performance of a task without conscious awareness of these previous experiences
-Explicit LTM -> Information that you have to consciously think about
Improving the accuracy of eye witness testimony
(description)
The cognitive interview, created by Fischer and Gielsman (1985-1992), is a thorough police interview that establishes accurate EWT recollections
Improving the accuracy of EWT
-Report everything
The individual has to detail every single thing that they remember. It is hoped that if they remember one memory, then more will be remembered
Improving the accuracy of EWT
-Mental reinstatement of context
Asking the individual to recall the environmental/ emotional aspects of the event
Improving the accuracy of EWT
-A change of narrative order
Witnesses are encouraged to detail and recall backwards. from the end to the beginning of the main events which occured
Improving the accuracy of EWT
-A change of perspective
Witnesses are asked to report the incident from different perspectives, describing what they think other witnesses might have seen
Factors affecting the accuracy of EWT
-Misleading information (through leading questions)
-Information that is said that changes the memory in our heads without us recognising. This can be done through leading questions
-Leading questions leads or persuades a person towards giving a particular response
-Evidence: Loftus + Palmer (1974), Loftus + Zanni (1975), Yuille + Cutshall (1986)
Factors affecting the accuracy of EWT
-Misleading information (through post-event discussion)
-When witnesses to a crime discuss the events with others, their memories can become contaminated
-Factors that could damage EWT: Media coverage, conformity and repeat interviewing
-Evidence: Gabbert et al (2003)
Factors affecting the accuracy of EWT
-Anxiety
-Witnesses may be in a state of high arousal; especially if there is a threat/ danger
-The Yerkes-Dodson model of performance suggests that memory operates best at a moderate level of anxiety. If too high, it can lead to a lower level of recall
-Evidence: Johnson + Scott (1979), Deffenbacher (2004), Yuille + Cutshall (1982)
Explanations for forgetting (p+r)
Proactive interference= When previous information interferes with recent information
Retroactive interference= When recent information interferes with previous information
Proactive-> Older affects newer-> Retroactive-> Newer affects older
Explanations for forgetting - cues
Context- Environmental cues which aid in accessing memories in a certain context
State- Having to be in the same physical/emotional state to access the memory
Organisational- Cues which are given to help the listener understand the order and sequence of the memory
Retrieval failure due to absence of cues
-Theory states that forgetting arises as the cues are not available for recall that were present during encoding
-Forgetting is an accessibility issue
Short-term memory - Research Evidence
-Jacobs
-Research suggest that STM has a capacity for between 5 and 9 ( 7+/- 2) items
-For example, Jacobs (1887) tested ppt’s ability to remember strings of letters and numbers. On average, the ppt’s could remember 7 letters before reaching capacity and 9 numbers.
-However, capacity can be increased by ‘chunking’ items into semantically similar groups. For example, a 11-digit phone number can be chunked into smaller groups
Absence of cues for forgetting - Research Evidence
-Darley et at (1973)
-State-dependent failure is when the internal environment during recall is different from the internal environment when the memory was coded
-Darley et al. observed that participants who forgot where they hid money while high on cannabis were more likely to remember where they hid that money once they got high again compared to when they were sober
Misleading information - Research Evidence
-Loftus and Palmer (1974)
-Loftus and Palmer conducted a study to test the effects of leading questions
-45 ppt’s were shown the same video clip for a car crash. After they watched the video, they were asked questions about the video clip.
-The ppt’s were divided into 5 groups and asked to complete the question, ‘how fast were the care going when they x into each other. They had to complete the sentence with; contacted, hit, bumped, collided and smashed
-Asking the question using a more intense verb, such as smashed, rather than a less intense verb, such as bumped, influenced the participant to estimate a higher speed
Components of the WMM - Central executive
-Research evidence - Baddeley
-Baddeley - Keyboard experiment
-Asked participants to generate random strings of of digits on a keyboard
-The task was carried out on its own, or with 1 of 3 tasks;
1.Reciting the alphabet, 2.Counting from 1, 3.Alternating between letters and numbers e.g. A1, B2, C3
-The generated digit string became increasingly less random in condition 3
-Baddeley concluded that both the random number generator task and the alteration task were competing for the same central executive resources
Components of the WMM - VSS
-Research evidence - Gathercole and Baddeley (1993)
-Participants were given a visual tracing task. At the same time they were given 1 of 2 tasks;
1.Describe the angles on the letter F
2.Perform a verbal task
-Ppt’s found task 1 difficult, but not task 2, presumably because the 2nd task involved 2 ‘slave systems’
-This is also evidence related to the effects of doing 2 tasks, using the same or different components
Components of the WMM - Phonological loop
-Research evidence - Baddeley (1995)
-Participants were given lists of long and short words to recall
-They recalled more short than long words
-This shows that the phonological loop can hold the number of items that can be said in about 2 seconds
-Since more short than long words can be said quicker, more short words are recalled
Components of the WMM - Episodic buffer
-Research evidence - Baddeley
-Used MRI scans to see which areas of the brain were most active during particular tasks
-For tasks that involved a combination of verbal and spatial information there was greater activity in the right frontal area of the brain
-For tasks that involved single sources of information, there was greater activity in the posterior area of the brain
-These results provided neurological evidence that the episodic buffer provides temporary storage for combined/integrated information
Factors affecting accuracy of EWT - Research evidence
-Loftus and Zanni (1975) (leading questions)
-Participants were asked to fill out a questionnaire about the speed of cars
-In one questionnaire, the questions began with; ‘did you see the?’ (the ‘the’ being definite)
-In the other, the question remained the same
-The results showed that 15% of participants ‘yes’ when the definite article was used, compared to 7% with the indefinite article
Factors affecting accuracy of EWT - Research evidence
-Loftus and Burns (1982) (anxiety)
-The study had 2 conditions; one violent and one non-violent. In both conditions Pt’s sae a video of a bank robbery
-One group of participants a film of a crime with no violence
-Another group were shown the same film but with a violent incident (a boy was shot in the face)
-Those who saw the violent incident recalled significantly less than those who saw the film without the violent incident: suggesting that the anxiety caused by the violence negatively affected recall
Factors affecting EWT - Research evidence
-Gabbert et al (2003) (post-event discussion)
-The sample consisted of 60 students from the University of Aberdeen and 60 older adults recruited from a local community
-Participants watched a video of a girl stealing money from a wallet. The ppts were either tested individually (control group) or in pairs (co-witness group)
-The participants in the co-witness group were told they had watched the same video, however they had watched different perspectives of the same crime and only 1 person actually witnessed the girl stealing
-The participants in the co-witness group discussed what they had seen and then completed a questionnaire
-Gabbert found that 71% of the witnesses in the co-witness group recalled information they had not actually seen and 60% said the girl was guilty
Improving the accuracy of EWT - Research evidence
-Fischer et al. (1990)
-Fischer trained detectives from the Miami Police Department to use the cognitive interview. Police interviews with eyewitnesses and victims were videotaped and the total number of statements were scored
-A second eyewitness was then asked to confirm whether these were true or false
-Compared to the standard procedure used, the cognitive interview produced 46% increase in recall and 90% accuracy
-The findings suggested that the cognitive interview is more effective than the standard interview, producing higher recall and reducing errors
Describing the MSM - Research evidence
-Sensory store (Walsh and Thompson 1978, Milter 1956, Sperling 1960)
-Duration -> Walsh and Thompson 1978: found that the sensory store has an average duration of 500 milliseconds, which decreases as individuals get older - suggesting the duration is limited on age
-Encoding -> Milter 1956: ‘the magical number 7, plus or minus 2’. The research suggested that organising stimulus into chunks, enables the STM to cope
-Capacity -> Sperling 1960: asked subjects to recall as many letters as they could from a grid of 12 symbols that he displayed on a screen for just 50 milliseconds, and found that they could only recall about 4 items
Describing the MSM - Research evidence
-STM (Peterson and Peterson, Baddeley, Jacobs)
-Duration -> Peterson and Peterson (1959): read nonsense trigrams to ppt’s and then got them to count backwards in 3’s from a large random 3 digit number for varying periods of time. After 3 seconds, there was 80% recall compared to 10% after 18 seconds
-Coding -> Baddeley (1966): Gave ppt’s 4 sets of words
1. Similar sounds e.g. cat, map, cap
2. Different sounds e.g. dog, bin, cup
3. Similar meanings e.g. bin, large, huge
4. Different meanings e.g. huge, good, light
When asked to recall immediately, ppt’s made more mistakes on words that sounded alike
-Capacity -> Jacobs (1887): tested STM capacity with the serial digit span method where participants are presented with increasingly long lists of numbers or letters and have to recall them in the right order. He found the capacity for numbers = 9.3 items and letters = 7.3 items
Describing the MSM - Research evidence
-LTM (Bahrick et al, Baddeley, Wagenaar)
-Duration -> Bahrick et al. (1975): used a sample of American ex-high school students between ages of 17 and 74. PPt’s were tested in several ways including free recall and a photo recognition test. The ppt’s were asked to identify their classmates from a set of 50 photos. Results showed the recognition group was 90% accurate after 14 years and 60% after 47 years
-Coding -> Baddeley (1966): same as STM coding evidence
-Capacity -> Wagenaar (1986): created a diary of 2400 events over 6 years and tested himself on recall of events rather than dates, finding he too had excellent recall, again suggesting the capacity of LTM is extremely large
