memory content Flashcards
what is the capacity, duration and encoding of the sensory store
cap: 9-18 items
duration: 250ms
encoding: modal specific
what is the capacity, duration and encoding of the short term memory (STM)
capacity: 5-9
duration: 18-30 secs
encoding: acoustic
what is the capacity, duration and encoding of the long term memory (LTM)?
capacity: unlimited
duration: unlimited
encoding: semantic
who created the multi store model? (MSM)
Atkinson and Shiffrin
how is information lost from STM and LTM?
displacement and decay
outline Peterson and Peterson’s trigrams study on duration of STM
3 nonsense letter trigrams show
They had to count back in 3s from
300 = no maintenance rehearsal.
The counting increased in 3 sec
intervals (3,6,9, up to 30 secs)
They found around 90% of trigrams
were remembered after 3 seconds,
5% after 18 seconds.
Duration STM = 18-30 secs.
outline evaluation points for P+P’s trigrams study
standardised procedure apart from change in length of maintenance rehearsal = high causation ensures its only looking at STM duration and not LTM.
lacks EV - mo semantics or consequence
describe Bahrick’s study on duration of LTM
50 photos shown from school yearbook.
Asked to match name to photo or free
recall.
Results:
Up to 15yrs -
• 90% accuracy matching
• 60% on free recall.
After 48 yrs -
• 60% recall matching
• 30% free recall
describe Baddeley’s study on encoding of LTM and STM
4 conditions:
Acoustically similar & dissimilar.
• Recalled immediately
• Recalled after 30 min
Semantically similar & dissimilar.
• Recalled immediately
• Recalled after 30 min
Results:
Acoustically similar sounding words (cat, hat etc) were confused on immediate recall.
STM = acoustic encoding.
Semantically similar words (e.g big, large
etc) were confused after 30 min recall.
LTM = semantic encoding.
describe Jacob’s digit span technique study on capacity of STM
Gave pps letters, numbers of words and increased them by one each time.
Asked them after each increase to immediately recall strings of letters/numbers.
Found that people could generally recall between 5-9 items. Chunking letters could increase capacity.
outline the points for MSM A03
Research Support for Duration of STM
- P+P trigrams
Research support high in ecological validity - clive wearing
Criticism of MSM it is reductionist (oversimplified STM and treats humans like computers) elaborative rehearsal?
describe episodic memory
Personal Autobiographical experiences
Strengthened by emotions at the time
Time-stamped, place and context of
memory also included (e.g. birthday)
Explicit Memory
Least resistant to forgetting
Areas of the brain: Right PFC
describe semantic memory
General Knowledge
Facts, meanings, concepts about our world
Knowledge had by many rather than personal experience. (e.g. capital of Paris)
Explicit Memory
Less resistant to forgetting
Areas of the brain: Left PFC &
hippocampus
describe procedural memory
Skills acquired through practise
Automatic memories
Knowledge of motor movement tasks (e.g. riding a bike)
Implicit Memory
Very resistant to forgetting
Areas of the brain: cerebellum,
caudate nucleus & motor cortex
describe Tulving’s study on LTM
PET scans, 6 pp’s performing
memory tasks.
Injection of radioactive traces of gold.
More blood flow to anterior (front) = episodic.
More blood flow to posterior (back) = semantic.
describe the case study of Clive wearing in relation to MSM
herpes virus damaged his ability to have
maintenance rehearsal.
only had a STM of up to 10 secs.
supports the MSM as it proves that we do need to maintenance rehearse information in STM, as without it Clive could not form long-term memories.
describe the case study of Clive wearing in relation to LTM
lost episodic memories, but retained some semantic (recalled wife) & full
procedural memories, e.g., how to play
piano.
Proves that there are different types as
each type was affected to a greater or
lesser extent. If one type of LTM then all
would be affected to same extent.
could argue playing piano is episodic as was a concert pianist and maybe recalling memories of playing the piano to play. Also required knowledge of reading music (semantic). - can’t generalise as very diff profession
what are the components of the working memory model?
central executive
phonological loop (PL store, articulatory loop)
visio-spacial sketchpad (inner scribe, visual cashe)
episodic buffer
what’s the role of the central executive?
It directs attention to particular tasks allocates the brains resources (slave systems) to them.
has limited capacity - can hold approx 3-4 items at a time.
what’s the role of the phonological loop?
deals with auditory information, and keeps the order of information.
phonological store: (inner ear) holds the words you hear for 2sec capacity
articulatory loop: for words seen or heard which are repeated (inner voice)
what’s the role of the visio-special sketchpad (VSS)
This deals with planning spatial tasks, the physical relationship between objects.
visual cashe: stores info about visual items (form and colour)
inner scribe: stores the arrangement of objects in visual field.
limited capacity
describe Baddeley and Hitch’s dual processing study
Condition 1. track a spot of light with a pointer whilst saying yes/no to angles on an imagined letter, e.g., F. (yes if angle is at the bottom or top line of the letter)
Condition 2. track a spot of light whilst doing a verbal task, e.g., answering questions.
Participants found it difficult to hold the image of the letter in their heads and track the moving light.
However, if asked to carry out a verbal task and track light they could perform both well.
VSS limited as can’t carry out both visual tasks at same time
outline A03 points for WMM
strength: research support for dual processing (Baddeley and Hitch)
strength: evidence from studies with higher EV - KF
criticism: WMM too vague (CE)
what are the 2 explanations of forgetting?
interference (pro/retroactive interference)
retrieval failure (context/state dependent forgetting)
what is proactive interference?
old information affects new information
(remember old, forget new)
e.g. you learn French and then Spanish. In Spanish you end up speaking French.
what is retroactive interference?
new information affects old (forget old, remember new)
e.g. get new pin, when you go to type your old pin in you can’t recall it
what are the key studies for interference?
Rugby players (RI)
Mcdonald and McGeoch (list A and B - similar and dissimilar) (RI)
outline the Rugby players study on interference
- Rugby Pp’s who had played several rugby games were asked to remember as many of the teams they had
played against they could. - some players had played all games and some had missed some due to injury
- Forgetting was more due to the number of games played (so interference of memory had occurred) rather than the amount of time that passed between games
outline McDonald and McGeoch’s study on interference
- Gave participants 10 adjectives (List A).
- They learned list A then had a break for
10 min and learned list B. They then recalled List A.
•List A & B similar = recall of A poor (12%)
•List B nonsense = recall better (26%)
•List B was numbers (very dissimilar) = recall best (36%).
list B (new info) was affecting then recall of old info (list A) (retroactive interference)
what are the two types of retrieval failure?
context-dependent failure
state-dependent failure
describe context-dependent forgetting
External retrieval cues different or
same as when learnt/encoded. E.g.,
learning information in a classroom
and recalling in an exam hall.
describe state-dependent forgetting
Internal retrieval cues different or
same as when learnt/encoded. E.g.,
eyewitness recalling a crime they
saw when drunk, when they were
sober.
outline the key study on context dependent retrieval
BOOB
18 divers learned lists of 36 unrelated words
B leant B recalled - 13.5
O learnt O recalled - 11.4
B learnt O recalled - 8.5
O learnt B recalled - 8.6
same context = higher recall - useful as shows we should learn and recall info in same external context. shows importance of learning in exam conditions to ensure a similar context.
(but not possible to do this all the time - e.g. EWT)
outline the key study for state dependent retrieval
48 medical students
day 1 - training, day 2 - testing
randomly assigned to 4 groups;
- SS, AA, AS, SA (A=intoxicated, S=sober)
more errors made in AS or SA conditions than AA and SS. SS performed best in all tasks.
so being in same internal state increases recall.
what are the 3 factors affecting eyewitness testimony (EWT)
leading questions
post-event discussion
anxiety
outline Loftus and Palmer’s Car crash study on leading questions
45 Students shown film clips of car accidents.
They were asked a variety of questions, but one that was experimental- “How fast was the car going when it… into
the other vehicle”
They added in 5 different verbs (hit, collided, smashed, bumped, contacted).
Hit: 31 mph mean; Smashed 41 mph (mean).
Leading Questions contaminate our memories (false memories). Therefore EWT is not reliable and should not be used if interviewers used leading questions.
outline Loftus and Palmer’s broken glass experiment
150 students, 7 film clips. Hit, smashed. Asked questions. Guess estimate mph.
One week later re-interviewed and asked question; ‘Did you see broken glass?’. More people reported seeing broken glass when verb smashed was used than hit.
Conclusion: More said broken glass in smashed than hit.
people were more likely to have a false
memory if they had had a leading question.
outline Gabbart’s study on post-event discussion
120 pp’s (1/2 students, ½ older people)
Pps watched a video of a girl stealing money from a wallet.
Condition 1: tested individually – control group.
Condition 2: tested in pairs (co witnesses).
They were told they had watched the same video, but they hadn’t
They were put together after to have a ‘post event discussion’.
They then completed a questionnaire.
- 71% of pp’s gave information they hadn’t seen
- 60% said the girl was guilty, despite not seeing her commit the crime.
outline the weapon focus study
Pp sat outside lab and thought they were hearing a genuine conversation with people inside.
Condition 1: amicable discussion about equipment failure, man came out holding a pen.
Condition 2: hostile discussion, sound of breaking glass.and overturned furniture; man emerged covered in blood, holding a knife.
Pps given 50 photos and asked to id the man.
Results: Condition 1 = 49% accuracy in id’íng man
6. Results: Condition 2 = 33% accuracy in id’ing man.
Weapon Focus Effect, attention on the
weapon rather than the face due to anxiety, so less accurate EWT
outline the Yerkes-Dodson law
There is an optimal level of arousal which enhances memory. Underarousal or overarousal leads to poor memory performance.
outline the London dungeon’s study
London dungeons (heart monitor to measure anxiety when scared). Results: high state of anxiety = fewer correct descriptors of person & inaccurate line up id.
This proves that the more anxiety the worse the accuracy of EWT, as the more physically anxious less recall. (but could be more due to surprise)
outline Pickel’s surprise study
looks at surprise vs perceived threat of a weapon.
pp’s watched a thief enter hair salon.
4 conditions: 1. Scissors, 2. handgun, 3. Wallet, 4. raw chicken.
The pp’s accuracy decreased to high surprise (raw chicken) than the handgun
(high threat). Therefore, this criticises the weapon focus theory and supports the theory that EWT is affected by surprise rather than weapon focused anxiety.
outline Yuille and Cutshall’s study
Canada armed robbery . Police interviewed EW’s and 13 were reinterviewed 4-5 months later. Accurate recall, even with 2 leading questions.
Highest levels of stress reported were the most accurate (88% - 75%).
Proves that in a real-life crime, EWT is accurate. Therefore, the weapon focus study was too underaroused and the London Dungeons over aroused (both not real crime situations).
This fits with Yerkes-Dodson Law: optimal anxiety which increases accuracy.
outline the characteristics of the standard interview?
- It feels more interrogatory and formal (lack of rapport/trust, so less likely to speak openly)
- Questions are not in sequential order
and Police will interrupt EWT (can reduce flow of memory, so less info given) - They will cross-question to check for inconsistencies
- Police may end up asking leading questions (lead to false memories)
outline the process of the cognitive interview
- recall everything
- reinstatement of context (using context and state dependent retrieval cues)
- reverse the order
- change perspective
use of rapport building, open questions
describe the role of the episodic buffer
added in 2000.
storage system that holds auditory and visual info.
has a limited capacity.
integrates info from CE, PL, VSS.
maintains time sequencing (episodic events)
