memory Flashcards
short term memory coding
coding - baddely 1966 - 4 word type - if recalled immediately worst with acoustically similar words, after 20 minuets semantically similar words were worse - short term memory coded acoustically
+ clear difference between types
+ application - resulted in multi-store memory model
- artificial stimuli
- limited application
short term memory capacity
jacob 1887 - read out 4 digits in order - if correct added another digit until failed - mean digit span = 9.3, mean number span = 7.3
miller 1956 - similar to jacob, but found STM had capacity of 7 +/- 2 chunks
Miller AO3
+ high internal validity
- cowan 2001 recreation, recreated miller and found STM capacity to be 4+/-1
- chunk size undefined
short term memory duration
peterson and peterson 1959 - 24 students in 8 trials each - given a syllable and 3 numbers to remember - had to count back from random number until told to stop to prevent rehearsal - after 3 secs ~80% remember - after 18 sec ~3% remembered
AO3
- low external validity - artificial task
sensory registers
where sensory inputs are automatically held - not under cognitive control
coding - no coding - raw format
duration - varies - crowder 1993 - storage lasts milliseconds in iconic but seconds in acoustic SR
capacity - unlimited/ very large
atkinson and shiffrin 1968 - model
states how info flows through memory -
rehearsal
| | rehersal SR -> STM -------------> LTM | |
baddley and hitch 1974 - Working memory model
disagreed with simplicity of STM - explanation not replacement for STM -
central executive
/ | \
phonological loop – episodic buffer – visual spacial sketchpad
\ | /
Long term Memory
AO3:
+ real life application - reading navigation and problem solving
+ does not over emphasis rehersal
- not a comprehensive model of memory only STM
- little direct evidence for CE
Central executive
filters between SR and STM - decided on what gets passed from SR to STM - diverts info to correct slave system - limited capacity, only one item at a time - directs attention by switching input to STM
baddley 1996 - struggled to do two tasks at once - demonstration limited capacity of CE
d’espacito et al 1995 - fMRI showed activity in prefrontal cortex when doing frontal and spacial tasks together but not separately - indicates increased strain on CE and location of CE
AO3:
- very little known about CE - magic bullet to explain all unknowns
- better understood as component than store
phonological loop
slave system responsible for auditory and ordering processing - limited capacity ~ 2 seconds but extended with rehearsal
baddley 1986 - 2 sub parts - Primary acoustic store responsible for stores speech and processes hearing - articullatory process the inner voice responsible for speech production, rehearsal and storing information from PAS
trojani and grosi 1995 - case study of brain damage victim, effected PL not VSS suggesting separate stores
baddley 1975 - word length effect - remembered more of the start of a word list - shows limited capacity and duration of PL
AO3
+ PET scan highlighted different areas of activity between PL and VSS tasks
+ explains the vocalization process well
vissuo-spacial sketchpad
responsible for visual and spacial storage and processing - helps navigation of physical environment - rehearsal through mental images
logic 1995 - 2 parts - visual cache stores visual material - inner scribe responsible for spacial relationships and rehearsal
gathercole and baddley 1993 - could do two visual tasks but not a visual and a visual and a verbal task at the same time
AO3
+ PET scans shows left hemisphere active in visual tasks and right hemisphere active in spacial task - evidencing separate visual stores
- tasks showing the difference VSS and PL artificial only
episodic buffer
general store - VSS and PL have no long term storage - explains how STM has 30 sec duration (peterson and peterson)
prechakaron et al 2000 - fMRI showed right frontal cortex activity for combined verbal and spacial tasks - evidence for episodic buffer Al Khalifa 2009 - p with LTM had duration of 25 sec - longer than duration of PL and VSS - evidencing separate general store
eye witness testimony
where a witness to a crime recalls events at trial devlin committee report 1976 - of 850 cases in 1973 347 with EWT as sole evidence - 74% of EWT only cases found guilty - 75% of those dissensions over turned
bartlett war of ghosts 1932
told western P’s narajo story - when P’s retold it they westernized the story, adapting it to their own experiences - memory not accurate snapshot of events - influenced by previous experiences, mood, context, attitude and stereotypes
EWT AO3
- low ecological value - lab study
- forter et al 1994 - EWT more accurate in real life
- missleading P’s
- psychological harm to P - forced to watch violent crash
- anxiety - deffenbucher 1983 - meta-analysis of 21 studies - high anxiety negatively effect EWT
- yerks-dodson inverted U - peak level of anxiety for best recall often exceeded
repression
defense to traumatic events can cause details to be buried in unconscious
freud 1894 - anxiety prevents traumatic events from being recalled
AO3:
- mostly lab based - not genralizeable
- ethical issues - causing trauma and decite
- not only factor in recall - age, gender, health conditions, language
cognitive interview
fisher and gieselman 1992 - 4 recall techniques combined into one interview
change of order
change of perspective
mental reinstatement - recalling the environment and context, not actual event
recall all - even if thought to be unimportant
tulving and thompson 1973 - added change of order and change of perspective to reduce the use of prior experience knowledge and schemes
gieselman et al 1985 - found CI to be more accurate than SPI
geiselman and fisher 1997 - time between interview and event effects accuracy
milne and bull 2002 - report everything and context reinstatement most effective
