Memory - Overview

Memory

1. Nature

   • Short term
     • Encoding
       • Visual, acoustic
     • Duration
       • Peterson and Peterson 1959
         • M: 24 students given 3 consonant syllable to be remembered and 3 digit number
           • Asked to count backwards from number until told to stop and recall the triagram, one interval of 3 seconds and 18 seconds
         • R: 3 second interval = ppts recalled 90%, 18 second interval = ppts recalled 2%
         • C: STM duration is 18 seconds
     • Capacity
       • Miller 1956
         • Concluded that span of stm is 7 +/- 2
         • Found we can recall 5 words as well as 5 letters as we chunk things together
       • Simon 1974
         • Found people had shorter span for larger chunks than smaller chunks such as one syllable words
   • Long term
     • Duration
       • Potentially unlimited as researcher can be outlived
       • Bahrick et al
         • M: Asked people of various ages to name faces from their high school year book 48 years on
         • R: 70% accurate
         • C: Long term memory can last for many years
     • Capacity
       • Potentially unlimited as no way of researching
     • Encoding
       • Visual, acoustic and semantic
   • Encoding
     • Baddeley 1966
       • M: Participants given list of words that were acoustically similar/dissimilar and list of words that meant the same/dissimilar
       • R: Participants had more difficulty remembering acoustically similar words in STM but not LTM
       • R: Semantically similar words no problem for STM, but problematic for LTM

2. Multi Store Model

   • Atkinson and Shiffrin 1968
     • Explanation of how memory processes work and stored in sensory memory, short term and long term
   • Process
     • Environmental stimuli goes to sensory memory
     • Attention to stimuli transfers information to short term memory
       • Disappears if not rehearsed (maintenance) or if displaced by new information
     • Elaborative rehersal transfers information to long term memory
   • Support
     • Sperling 1960
       • M: Asked ppts to recall 12 letters/digits from a grid after 50 millisecond delay
       • R: Poor recall when asked to recall all 12: 42%
       • R: Recall of 75% when asked to recall one row
       • C: Information decays rapidly in sensory store
     • Glanzer and Cunitz 1966
       • M: Asked ppts to recall a list of words
       • R: Words at beginning of list more recalled than at the end of list
       • C: Serial position effect - first words transferred to LTM, end words in STM
     • Beardsley 1997
       • Brain scans found that prefrontal cortex is active in STM tasks
       • Hippocampus is active when LTM engaged
       • C: Shows separate stores for STM and LTM
     • Patient HM
       • Case study where patient had hippocampus removed due to sever epilepsy
       • R: Unable to form new LTM, but personality and former LTM intact
       • C: LTM and STM are separate stores
   • Limitations
     • STM and LTM not unitary stores
       • Clive Wearing
         • Brain damaged patient could not form new memories nor remember old ones
           • Could still play piano perfectly and loved his wife
         • C: We have different types of memories in LTM - declarative and procedural
     • STM and LTM not separate
       • Chunking to increase STM capacity relies on LTM to understand meanings
       • C: MSM is too simplistic

3. Working Memory Model

   • Explanation of short term memory based on 4 components
     • Central executive
       • Coordinates other mental functions
     • Phonological loop
       • Phonological store - stores heard words
       • Articulatory process - allows maintenance reherasal
     • Visuo-spatial sketchpad - stores visual and spatial information
       • Visual cache
       • Inner scribe
   • Support
     • Hitch and Baddeley 1976
       • Showed performance was slower when ppts given task with central executive and phonlogical loop
       • Better performance when task involved phonological loop alone
     • Bunge 2000
       • Used fMRI scans to show activity in brain
       • R: Same area active in single and dual tasks, but greater activity in dual tasks
       • C: Supports central exec that all information passes through it
     • Word length effect
       • Shorter words easier to remember than longer ones
       • Phonological loop can hold information you can say in 2 seconds
       • List of 3 letter words better recalled than list of 9 letter words
       • C: Supports separate stores
     • Patient KF
       • Case study of brain damaged patient whose LTM intact but he had problems with STM
       • Problems remembering auditory information but fine with visual information
         • Brain damage in phonological loop
       • C: Support for separate stores in STM
   • Limitations
     • Central executive vaguely defined and may consist of separate components
       • Eslinger and Damasio 1985
         • Showed brain damaged patient had no decision making skills but performed well on reasoning tests
           • C: Central exec may be split
     • Brain damaged patients
       • We cannot make before and after comparisons of patients
       • Not causal that changes in behaviour are caused by damage
       • Brain injury is traumatic which can alter behaviour

4. Eye Witness Testimony

   • Legal term referring to the use of witnesses who have seen or heard an event, giving evidence in court
   • Misleading Information
     • Loftus and Palmer 1974
       • Experiment 1
         • M: 45 students shown films of car accidents and asked questions afterwards
           • One critical about speed, 'how fast were the cars going when they ... into each other'
             • Different groups given different verbs - hit, smashed, collided, bumped, contacted
         • R: Smashed - group estimated higher speed than group who had contacted
         • C: Leading questions post event can have a significant effect on memory recall
       • Experiment 2
         • M: Ppts shown a film of an accident, week later asked if there was any broken glass
         • R: Ppts with verb smashed more likely to recall broken glass even if there was none
         • C: Post event information affects initial storage
     • Loftus et al
       • M: Ppts given photos of car at a junction with stop or yield sign and given questions either consistent with photo or inconsistent
       • M: Ppts shown pairs of photos and asked to identify original photo
       • R: Those with consistent qs were 75% correct, those with inconsistent were 41% correct
       • C: Misleading information affects recall
   • Anxiety
     • Deffenbacher 2004
       • Meta analysis of 18 studies on effects of anxiety on EWT
       • Showed stress negatively impacted EWT
     • Christianson and Hubinette 1993
       • Questioned 58 witnesses to bank robberies
       • Found those who were threatened had more accurate recall than onlookers
     • Yerkes-Dodson law
       • States performance improves with arousal to an optimal level then declines
       • Curvilinear relationship between anxiety and EWT
     • Johnson and Scott
       • M: Man ran through a room carrying pen covered in grease OR knife in blood
       • R: Ppts 49% accurate in identifying man with pen, knife = 33% accurate
       • C: Witnesses focus on presence of a weapon rather than peripheral details
     • Loftus
       • M: Monitored eye movements of a witness in an event
       • R: Presence of a weapon causes attention physically drawn to weapon itself and away from other details
   • Age
     • Yarmey
       • R: Older adults less confident in recall of a confederate, but same accuracy as younger adults
       • M: Stopped 651 adults and asked to recall characteristics of woman they spoke to for 15 secs, 2 minutes prior
     • Memon
       • Found accuracy in older people dropped when identification task delayed for a week
     • Pool and Lindsay 2001
       • Studied children aged 3-8 watching a science experiment
       • M: Parents read them a story with info of science experiment, but with info
       • R: Children incorporated added information when questioned about science experiment
         • C: New information affected initial version of events
     • Anastasi and Rhodes 2006
       • R: Younger ppts more accurate, but all age groups are more accurate in identifying photographs from their own age group
       • Own age bias
         • We have more contact with people our own age
       • M: Ppts shown 24 photos, asked to rate attraction, given filler activity, shown 48 photos and asked to recall the 24 they'd seen in 48
       • Used ppts from 3 different age groups: 18-25, 35-45, 55-78
   • Cognitive Interview
     • Fisher and Gieselman 1992
       • 1) Report everything
       • 2) Mental reinstatement
       • 3) Change of order
       • 4) Change of perspective
     • Technique for interviewing witnesses to a crime, encouraging them to recreate original context to increase accessibility of stored info
     • Support
       • Kohnken 1999
         • Meta analysis - 34% more correct info given in CI than in normal interview
       • Milne and Bull 2006
         • M: Tested components individually and combining components
         • R: Combination of 1 and 2 gave better recall than an individual component
         • Used College students and children
       • Stein and Memon 2006
         • M: Watched an abduction video, then interviewed with CI
         • Used female cleaning staff in Brazil
         • R: Increased recall in CI, especially for descriptions
           • C: Shows how useful CI can be, and how it can reduce miscarriages of justice
     • Limitations
       • Time consuming
       • Interviewers need to be specially trained
       • Kebbell and Wagstaff
         • Different police forces use different versions of CI
           • Makes comparison difficult of effectiveness
       • Can cause psychological harm

5. Memory Improvement

   • Verbal
     • Acronyms
       • ROYGBIV
     • Acrostics
       • My very easy method just speeds up naming planets
     • Rhymes
       • Using tune of twinkle twinkle to alphabet
     • Chunking
       • Phone numbers and post codes
     • Support
       • Gruneberg
         • Found 30% of psychology students revised using mnemonics
       • Broadly
         • Studied 63 children with down syndrome
         • Found training in memory improvement showed improved STM compared to a control group
     • Limitations
       • Research conducted in lab conditions, may not apply to everyday life
   • Visual
     • Loci
       • Associating material to be learned with different locations of a place and mentally retracing steps
     • Keyword
       • New word broken into components with images created for each component
         • e.g Foriegn words associated with English equivalent
     • Mind maps
     • Support
       • O'Hara
         • Found training in use of these techniques gave LTM benefits for older adults
       • Atkinson
         • Found ppts using keyword method, learnt significantly more Russian vocab than control gorup
     • Limitations
       • Slavin
         • Keyword method yet to be proven for long term advantages
   • Organisation
     • Bower
       • M: Gave ppts 112 words to learn
       • R: Recall was 2-3 times better if words in hierarchy than random order
       • Mnemonic techniques speeds up memory naturally organising itself
     • Naturally - memory involves associations in the brain in hierarchys
   • Elaborative rehersal
     • Craik
       • Found words processed more semantically were more remembered
       • Elaboration such as mind maps lead to more enduring memories
     • Mnemonic techniques make us elaborative rehearse them
   • Dual coding hypothesis
     • Pavio
       • Said words and images processed separately
       • Words made into images double encoded - once verbally and once visually