Memory Flashcards
Sensory store duration
0.25 - 2 seconds
Sensory store capacity
Large (attention moves into STM)
Encoding for sensory stores
Echoic - auditory
Iconic - visual
Capacity of STM
7+-2
Duration of STM
30 seconds
Study for duration of STM
PETERSON and PETERSON
3 letters and then count down backwards
Found it dropped from 3 seconds 90% - 18 seconds 10%
Lab study - low ecological validity, high control, repeatable, high reliability
Repeated measures, could get practice effects - counterbalanced by having people start at different times
Participant variables
Encoding
Changing sensory input into a form or code to be processes by the memory system.
Study for encoding information into STM
BADDELEY 1966
List of acoustically similar and dissimilar + same for semantic
Acoustically similar were muddled up in short term
Suggests acoustic encoding
Encoding for STM
Acoustic
Types of LTM
Episodic - personal event (conscious)
Semantic - capital of country (conscious)
Procedural - riding a bike (unconscious)
Capacity of LTM
Infinite
Study for duration of LTM
BAHRICK ET AL
Had to recall people from their school: free recall test
Some could remember up to 50/60 years
Shown pictures and remembered more: photo recognition test
Or given names and have to match to photos: name recognition test
Within 15yrs: 90% recognise names and faces + 60% free recall
30 yrs: 30% free recall accuracy
48 yrs: name recognition 80% + photo recognition 40%
Lab study
Field study - high ecological val, hard to control variables (lowers reliability): some people might stay in contact, cant control independent variable
Study for duration of LTM
BADDELEY 1966
List of 10 words
Acoustic dis/similar, semantic dis/similar
Semantically remembered in LTM
Had a 20 min gap after told list
Lab study - artificial, highly controlled
Encoding for LTM
Semantic
The multi store model of memory
ATKINSON and SCHIFFRIN 1968
Incoming stimuli -> sensory stores -> attention -> STM -> rehearsal -> LTM -> retrieval -> STM
Evidence that STM and LTM are separate
- Encoded in different ways (Baddeley studies)
- Primacy and recency effects in the serial position effect
- Studies of patients following brain damage (HM and KF)
Evidence of primacy and recency effects in the serial position
Primacy effect: first words of list in LTM as rehearsed.
Recency effect: last words in STM so easily recalled
Glanzer and Cunitz 1966
Put in a delay before people recalled 10 words, count backwards for 3 seconds at end of last word. Eliminated recency effect supports idea recency effect reflects STM.
Evidence from studies of patients with memory problems following brain damage
HM
Surgery to fix epilepsy
Removed hippocampus
After that STM and LTM fine but no link between memory, couldn’t make new LTM
Supports multi store model of memory as both stores are separate
But he could remember how to do hard drawing games suggests LTM is separated into different stores supports working model but contradicts multi store model as too simple
Not lab study, good
Case study - Low population validity, cant generalise, unique situation
Evidence from studies of patients with memory problems following brain damage
KF
Fell off motorbike, damage to brain
LTM fine, STM was reduced - remembered 3 things, so couldn’t make LTM
Evidence for MSM
But criticism of model as well as he could remember 7+-2 shapes - supports Working model
Evaluation of multi-store model of memory
+ supported by primacy and recency effect
+ supported by HM and KF
+ supported by Baddeley’s encoding studies
- overly simple
- KF had good visual memory, so means there is another store
- HM could learn skills like puzzles and mirror drawing, suggests there is another LTM store
Duration of LTM
Infinite
Working memory model
BADDELEY and HITCH 1974
Central executive at top
Episodic buffer in middle
Visuo-spatial sketch pad: visual cache, inner scribe left
Phonological loop: articulatory control system and phonological store (inner ear and voice) right
Long term memory at the bottom
Evidence that articulatory control processes and acoustic store are separate
Paul Esu
PET scans
Injected people with radioactive glucose while out in a pet scanner
Two tasks:
1. Remember series of letters, use inner voice and ear
2. Say whether they rhyme, inner voice
Found different parts of brain being used suggesting different/separate inner voice and inner ear
Unethical as injected radioactive glucose - low risk, necessary, important info and all consented
Evaluation of working memory model
+ more complex
+ considerable research support
+ KF
+ practical applications: understand children with reading problems
- not enough information/evidence regarding the central executive - not a single system, consists of several interacting systems
- some evidence visuospatial sketchpad may need to be split into visual and spatial
- no information about LTM
- evidence is flawed
Explanations for forgetting
Interference theory
Retrieval cue failure
Interference theory
Proactive interference - old info interferes with new.
Retroactive interference - new info interferes with old.
Problem with interference theory for forgetting
Only explains when two similar bits of info gets forgotten.
Evidence for interference theory
BADDELEY and HITCH
Two groups of rugby players, group 1 played recently and lots of games, group 2 played long time ago but fewer games
Group 2 better as no interference, group played less remembered more
Quasi, not full control, more realistic
Retrieval cue failure
Occurs when the info is still in LTM but there aren’t enough cues to retrieve the info.
Our memories can only be retrieved if we have cues or prompts to help retrieve them.
Evidence for retrieval cue failure
GODDEN and BADDELEY
4 people in each group
1+2 learned water, 3+4 land
1+3 tested water, 2+4 tested land
Those that tested in same remembered more words as had retrieval cues
Field study, good ecological validity but very artificial study, not a normal situation
16 scuba divers, rich, poor population validity
Practical implications, learn where tested
Problem with retrieval cue failure theory
Research supporting is highly artificial and with small sample sizes.
Eye witness testimony
When an observer of a crime’s recollection of events is used as evidence in a criminal trial.
Memory can be influenced by…
We can ‘reconstruct’ an account of events and this can be influenced by our prior knowledge and expectations and it may also influenced by things we’re told after the events.
Memory is reconstructive.
3 factors that affect the reliability of EWT
- Anxiety
- Misleading information (and leading questions)
- Improving EWT using the cognitive interview
Evidence for anxiety affecting EWT
LOFTUS 2 groups one saw pen, one saw bloodied knife Identify man : 49% pen, remembered but saw knife down to 33% Anxiety and weapon focus Not generalisable to real life Deception - ethical No risk High control
Evidence for misleading information
LOFTUS and PALMER See video of car smashing in each other 41 mph for smashed and 34 for hit Misleading questions Lab - no anxiety, not realistic Always used uni students, not representative sample Deceived Practical implications - improve justice system, police be careful what they ask
Post event discussion evidence
GABBERT ET AL
Participants group 1 watched video girls stealing wallet
2 watched everything but crime
Asked to meet and discuss on assumption both saw same video
Group 2: 71% said saw things they couldn’t see
60% said she was guilty
Supports idea post event discussion negative effect on ewt
Lab study
Police question asap so not influenced by others
The cognitive interview
GEISELMAN
Cognitive interview
Context, Report, Order, Perspective
2 groups, one undergraduate saw video of crime and interviewed
One interviewed with cognitive
Cognitive interview - remembered more information but not more accurate
No anxiety and used students
Follow up with real crimes and found same results
