memory Flashcards
encoding
The format in which information is stored
capacity
The amount of information that can be held
duration
The length of time information can be held
sensory memory
receives information from the environment through our senses
trace decay
information is lost quickly if no attention is given to it
encoding of sensory memory
depends on the sense
duration of sensory memory
less than half a second
capacity of sensory memory
very high
key study of sensory memory by who..?
Sperling
duration of sensory memory study
Procedure: a grid of letters & numbers displayed for less than a second
Findings: 5/12 items remembered, but when asked to recall a row 3/4 items remembered but still knew 12 items were there
Conclusion: Info decays in less than two seconds
capacity of sensory memory study
Procedure: a grid with letters & numbers displayed, accompanied by a tone which related to what row the participants should recall
Findings: participants remembered more letters than they wrote because their memory faded too fast
Conclusion: sensory memory had a large capacity but a short duration
short term memory (working memory)
information we are consciously aware of due to the attention it has been given
encoding of short term memory
acoustically
duration of short term memory
18-30 seconds
capacity of short term memory
7 +/- 2 (so, 5 or 9
encoding of STM study
Conrad
Procedure: sequence of six consonants presented to participants
Findings: letters with similar sounds were more difficult to recall correctly than those with different sounds
Conclusion: STM is encoded acoustically
duration of STM study
Peterson & Peterson
Procedure: 24 participants recalled triagrams which were presented one at a time. They were recalled after intervals of 3,6,9,13,15,18 seconds and after seeing a triagram, participants has to count backwards
Findings: The longer participants had to count backwards, the less they could recall triagrams
Conclusion: STM has limited duration
capacity of STM study
Jacobs (1887)
Procedure: participants repeated a list of numbers & letters in the right order, with the amount of items increasing until participants could not recall the list anymore
Findings: there was an average item span of 7.3 to 9.3 digits
Conclusion: the capacity of STM is 7 +/- 2
capacity of STM study (2)
Miller (1956)
Findings: the capacity of STM can be increased by combining separate chunks of information
encoding of long term memory
semantically (meaning)
capacity of long term memory
unlimited
duration of long term memory
unlimited
encoding of LTM study
Baddeley (1996)
Procedure: participants given one list of words and were asked to recall them in the right order
Findings: when asked to recall after 20 minutes, semantically DIFFERENT words were remembered inaccurately
Conclusion: LTM is encoded semantically
capacity of LTM study
NO STUDIES
- too much information in the brain
- assumed to have unlimited capacity
duration of LTM study
Bahrick (1975)
Procedure: 392 American ex-highschoolers aged 17-74 asked to recall from their yearbooks. Free recall test -> asked to recall NAMES of as many peers as possible. Photo recognition -> shown 50 photos and had to identify who they remembered
Findings: participants tested within 50 years of graduation were 90% accurate, after 48 years recall declined to 70%. Free recall -> after 15 years it was 60% accurate, after 48 years it was 30%
Conclusion: LTM has unlimited duration
Multi-store Model
Atkinson and Shiffrin (1968)
- A stimulus from the environment enters the sensory register, paying attention to this information sends it to the STM store. If this information is rehearses it is sent to the LTM store.
Draw the multi-story model
Sensory STM store LTM store
Register
Evaluation of Multi-store model
✔️evidence to support (Clive)
✔️scientific evidence to support (MRI brain scan)
❌too simplistic (research has shown that the STM store has multiple stores within it)
❌too much emphasis placed on rehearsal (traumatic events are automatically remembered due to the stress experienced)
Working memory model
Baddely and Hitch
- a more complex version of the STM which focuses on processes rather than structures
Draw the working memory model
- Central Executive
- Visuo-spatial sketchpad (inner scribe & visual cache)
- Episodic buffer
- Phonological loop (inner ear & inner voice)
- Long Term Memory
Central Executive
- Controls attention and directs information to its two slave systems - the visuo-spatial sketchpad & phonological loop
- Co-ordinates activity
- Limited capacity
Phonological Loop
- Deals with auditory information
- Subcomponents:
⚫️Articulatory Control process (inner voice) -> allows for sub-vocal repetition of items in the phonological store, known as maintenance
⚫️Phonological store (inner ear) -> stores acoustic items for a short period
Visuo-spatial sketchpad
- Deals with visual and spatial tasks
Subcomponents:
⚫️Inner scribe -> deals with the spatial relationship between objects
⚫️Visual Cache -> stores visual information
Episodic buffer
- Binds and integrates information from other components
- Sends information to the LTM store
- Temporary storage system for the central executive
Evaluation of working memory model
✔️evidence to support (KF motorcycle accident)
✔️dual-task performance studies (both tasks compete for the two slave systems - Baddely)
❌role of central executive unclear (Baddely argues it is the most important system but the least understood)
Types of LTM - Episodic memory
Memories for personal events
- Consciously retrieved with effort
Types of LTM - Semantic memory
Knowledge of the world
- Consciously retrieved with effort
Types of LTM - Procedural Memory
Examples of knowing how…
- Behaviours are unconscious
Forgetting
Failure to retrieve memories
Displacement
when the STM is full, new information pushes out the old information and takes its place
Interference Theory
forgetting due to one memory blocking another, causing one or both memories to be distorted
Proactive Interference
past learning interferes with new learning
Retroactive Interference
new learning interferes with past learning
study for proactive interference
Keppel and Underwood
Procedure: meaningless three-letter consonant triagrams were presented at different intervals, and participants had to count backwards to prevent rehearsal
Findings: participants remembered triagrams that were presented first, despite length
Conclusion: results suggest proactive interference occurred as memory for earlier consonants that had transferred to LTM was interfering with memories of new consonants.
study for retroactive interference
McGeoch and Mcdonald
Procedure: participants had to learn a list of 10 words until they remembered them with 100% accuracy. Then they learned a new list. There was 6 groups -> synonyms, antonyms, unrelated words, consonant syllables, three-digit numbers, and no list.
Findings: when participants recalled the original list, the similar material produced the worst recall. This shows interference is strongest when the memories are similar
Conclusion: the reason similarity affects memory is due to retroactive interference because new information overwrites previous similar memories
Retrieval cues
a trigger of information that allows us to access a memory
Context-dependent forgetting
Recall depends on external cues
State-dependent forgetting
recall depends on internal cues
Retrieval failure
forgetting that may occur when we don’t have the necessary cues to access a memory
study for context-dependent forgetting
Godden and Baddely (1975)
Procedure: divers had to learn a set of words on dry land or underwater, and then tested in 4 conditions -> Learn on land = recall on land , learn on land = recall underwater, learn underwater = recall on land, learn underwater = recall underwater.
Findings: recall was found to be worse when participants were in a different context to coding & recall was found to be better when coding was in the same context
study for state dependent forgetting
Goodwin et al (1969)
Procedure: Male volunteers asked to remember a list of words when they were either drunk or sober. After 24 hours, they were asked to recall the list either drunk or sober
Findings: Recall scores show information learned when drunk was recalled better when drunk
leading questions
questions which suggest the answer
post-event discussion
when witnesses discuss their experiences with a co-witness, their memories may become contaminated.
Conformity effect
co-witnesses start with different views of the events but during discussions they begin to change their view of what happened
Repeat intervieing
with every interview that takes place, there is a chance that interviewers comments will change the witnesses recall
study for leading questions
Loftus and Palmer (1974)
Procedure: university students were shown film clips of car accidents and then asked questions about it - there was one critical (leading) question -> “how fast were the cars travelling when they hit,contacted,bumped,collided or smashed?”
Findings: the mean estimated speed for each condition was calculated. “contacted” = 31.8mph, “smashed” = 40.5mph. This shows depending on words used, answers will change
Conclusion: This shows the impact leading questions can have on a participants answers to the same clip
Evidence against leading questions
Yuille and Cutshall (1986)
Procedure: they interviewed 13 people who witnessed an armed robbery in Canada, where the robber was shot dead. Interviews took place more than four months after the crime, and included two leading questions
Findings: despite the leading questions, witnesses were accurate in their accounts
Conclusion: Leading questions didn’t affect the eye witness testimonies, perhaps this is due to the stress or trauma of the incident
study of post-event discussion
Gabbert et al (2003)
Procedure: pairs of participants individually watched a film of the same crime but filmed from a different point of view - this meant that each person could see different elements of the crime that others could not. The participants then discussed what they had seen together, before being separately asked
Findings: 71% recalled aspects of the crime they didn’t see, compared to 0% of a control group that had no discussion
anxiety
witnesses to a crime often experience anxiety, which has a chance of effecting the accuracy of the eye witness testimony / recall
study for anxiety recall
Yuille and Cutshall
Procedure: participants asked to recall the incident, they were also asked how stressed they had felt using a 7 point scale
Findings: those with the highest levels of stress had the most accurate recall - 88% compared to 75% for low stress
weapons focus effect
when a witness focuses on a weapon, they fail to notice other elements of the crime
study of anxiety impairing recall
Loftus
Procedure: participants sat outside a lab and overheard a genuine exchange between people inside it. Condition1 -> heard a calm discussion, a man with greasy hands came out holding a pen, Condition2 -> heard a heated discussion followed by the sound of breaking glass and overturned furniture, a man with blood on his hands came out holding a paper knife.
Findings: participants shown 50 photos to identify who did it. 49% correct in condition1, but only 33% correct in condition2.
Conclusion: anxiety caused by seeing the knife and hearing the distress took attention away from the identity of the man
Yerkes-Dodson Law
moderate anxiety is associated with better recall than very high or low anxiety
Report everything
witnesses are encouraged to include every detail they remember of the event , even if it seems irrelevant
Mental reinstatement
witnesses should return to the original crime scene in their mind to imagine the environment and their emotions at the time.
Change of order
events should be recalled in a different chronological order to the original one. This is done to prevent expectations and dishonesty
Change of perspective
witnesses recall the event from other peoples perspective. This is done to disrupt the effect of expectations
