Memory

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Created by
Isabel Kelleher

Cards (30)

  • Coding
    • Process of converting information between different forms
    • Baddeley 1966
    > Gave 4 groups of ppts 4 word lists, acoustically similar and dissimilar + semantically similar and dissimilar
    > Ppts shown original words and asked to recall then in correct order
    > Recalling immediately (STM) accoustically similar was worst
    > Recalling after 20 minutes (LTM) semantically similar worst
    • STM = acoustic
    • LTM = semantic
  • Coding Evaluation
    + Identified clear difference between memory stores. Later research has shown some exceptions but STM and LTM coding mostly stood the test if time. Led to MSM
    -Artificial stimuli, no personal meaning to ppts, so processing meaningful information may be different in everyday life. Limited application
  • Capacity
    • Jacobs 1887:
    > Measured digit span
    > Researcher read out 4 digits and ppts recalls out loud in right order
    > Digits increase until ppts gets the order wrong
    > Mean digits 9.3, mean letters 7.1
    • Miller 1956:
    > Observation of everyday practice, noted things come in sevens
    > So thought capacity of STM is roughly 7 items ± 2
    > Also noted people can recall 5 words as easily as 5 letters, we do this by chunking
  • Capacity Evaluation
    + Jacobs study has been replicated now in more controlled conditions and found same results. Suggests his study is a valid test of digit span in STM
    -Miller may have overestimated STM capacity, Cowan 2001 reviewed other research and concluded capacity of STM is 4 ± 1 chunks. Suggests Miller's lower estimate is more appropriate
  • Duration P1
    • Peterson and Peterson 1959:
    > Tested 24 students in 8 trials each, each trial gave a consonant syllable (YCG) to remember. Then given a 3 digit number to count backwards from to stop rehearsal
    > Each trial were told to stop at varying times (3-18 seconds in 3 second intervals)
    > 3 seconds had 80%
    > 18 seconds had 3%
    > STM duration is 18 seconds unless rehearsed
  • Duration P2
    • Bahrick et al 1975:
    > 392 USA ppts aged 17-74 and recall was tested in various ways:
    1. Used yearbooks as photo recognition of 50 photos
    2. Free recall of names in graduating class
    > Photo recognition after 15 yrs was 90% and 48 yrs was 70%
    > Free recall after 15 yrs was 60% and 48 yrs was 30%
    > LTM duration may be a lifetime
  • Duration Evaluation
    -Peterson and Peterson stimulus was artificial. Not completely irrelevant because sometimes we do try to remember fairly meaningless material (like phone numbers). But otherwise consonant syllables do not reflect everyday memory. Lacks external validity
    + Bahrick's study has high external validity because they investigated meaningful memories. When studies on LTM conducted with meaningless pictures recall was lower. Suggests Bahrick's findings reflect a more real estimate on duration of LTM
  • Multi-Store Model of Memory
    • Sense- Multisense coding
    > Very high capacity, <0.5 second duration
    • STM- Mainly acoustic coding
    > 7 ± 2 item capacity, 18-130 second duration
    • LTM- Mostly semantic coding
    > Potentially unlimited capacity, potentially lifetime duration
  • Multi-Store Model of Memory:
  • MSM Evaluation
    + Support from Baddeley (coding), study clearly show that STM and LTM are separate and Independent memory stores, as claimed by the MSM
    -Case study of KF- amnesia, his STM for digits very poor when read to him but much higher when read himself. Suggests multiple stores for STM
    + Case study of Clive Wearing, brain injury could still play piano and remember long term but couldn't remember what had happened minutes before. Shows LTM and STM separate but LTM has more than one store
  • Types of LTM
    • Tulving 1985:
    > Episodic- events, timestamped, conscious
    > Semantic- facts, not timestamped, conscious
    > Procedural- actions, not timestamped, unconscious
  • Types of LTM Evaluation
    + Case studies, Clive Wearing and HM, their semantic memories were relatively untouched- HM couldn't remember stroking a dog half an hour earlier but didn't need the concept of dog explaining
    +/- Brain scans, show separate areas for different stores which supports separate stores but often scans contradict each other so hard to pinpoint a store to an area
    -Tulving 2002 says episodic is subcategory of semantic, his research showed some amnesiacs have functioning semantic alongside damaged episodic but can't have other way around
  • Working Memory Model- Baddeley & Hitch 1974
    • Central Executive- supervisory role, divides attention, limited capacity, no storage
    • Phonological Loop- auditory info, acoustic coding, preserves info's order, 2 parts= phonological store & articulatory process (maintenance rehearsal, capacity = 2 seconds)
    • Visuo-spatial Sketchpad- stores visual and spatial info, Capacity= 3/4 items. Divided into visual cache (visual store) & inner scribe (arrangement in visual field)
    • Episodic Buffer- added in 2000, temp store, integrates all info. Capacity= 4 chunks, links WMM to LTM and other cognitive processes
  • Working Memory Model Evaluation
    + Case study, KF had poor STM for auditory info but could process visual info normally. Phonological loop damaged but VVS intact = separate stores
    + Dual task, Baddeley 1975- had ppts carry out verbal and visual task at same time and performance was same as when done separately. But when both either visual or verbal performance declined substantially. Shows must be two separate systems
    -Central Executive, lack of clarity over it's nature, Baddeley 2003 recognised that it's most important but least understood, needs to be more specified than just attention
  • Explanations for Forgetting: Interference
    • Mostly in LTM
    • Proactive- old memory interferes with new
    • Retroactive- new memory interferes with old
  • Explanation for Forgetting: Interference Study
    • McGeoch and McDonald 1931:
    > Studied retroactive by changing similarity between two sets of materials
    > Ppts learnt word list until could recall 100% accuracy, then learned new list of:
    1. Synonyms
    2. Antonyms
    3. Unrelated
    4. Consonant Syllables
    5. 3 digit numbers
    6. No list (Control)
    > When asked to recall original list the most similar material (synonyms) produced worst recall
    > Interference is stronger when memories similar
  • Explanation for Forgetting: Interference Evaluation
    + Baddeley and Hitch 1977- rugby players from same season (varying games, injury) asked to recall all teams, ones played most games had worst recall, some real world situations= increased validity
    -Tulving and Psotka 1971- gave ppts categorised word lists, 70% recall for first but got worse after each, when given cues recall rose to 70% again, interference is only temporary
    -Lab studies and artificial task reduce validity as not representative of everyday
  • Explanations for Forgetting: Retrieval Failure
    • Encoding Specifically Principle
    • Tulving 1983:
    > A cue is only helpful if it is present at encoding and retrieval
    > If cues are absent forgetting will happen
    • Context-dependent: recall depends on external cue
    • State-dependent: recall depends on internal cue
  • Context-Dependent forgetting
    • Godden and Baddeley 1975:
    > Divers learned list of words either on land or under water
    > Then asked to recall in either same or different environment (4 conditions overall)
    > Recall was 40% lower in non-matching conditions
    > Concluded external cues available at learning were different from the ones available at recall and this led to retrieval failure
  • State-Dependent forgetting
    • Carter and Cassaday 1999:
    > Gave antihistamines to their ppts which had slight sedative effect (different state)
    > Had to learn word lists and passages of prose before recall, with 4 conditions
    > In conditions that where mismatched performance was significantly worse
    > When cues are absent there is more forgetting
  • Explanations for forgetting: Retrieval failure evaluation
    + Real world application, strategies to use cues in everyday life
    + Support from Godden and Baddeley and Carter and Cassaday
    -Context effects may depend on type of memory tested. Godden and Baddeley 1980 replicated underwater study but with recognition rather than recall. Performance same in all conditions so retrieval failure is a limited explanation
  • Eye Witness Testimonies: Misleading Info- leading questions
    • Loftus and Palmer 1974
    > 45 students saw film clips of car accident, then asked questions about accident
    > Main question was to estimate cars speed, each group had a different 'verb'. E.g. Hit, Contacted and Smashed
    > Mean estimate. Contacted= 31.8mph and Smashed= 40.5mph
    • Response-bias explanation= wording has no effect on memory just influence how they answer
    • Substitution explanation= wording changes memory of clip- their 2nd experiment 1974, ones that hard smashed more likely to 'remember' broken glass
  • Eye Witness Testimonies: Misleading Info- post-event discussion
    • Gabert et al 2003
    > Ppts in pairs watched video of the same crime but with different perspectives
    > Then discussed what they had seen before recall test
    > 71% of ppts recalled aspects of the event they hadn't seen but heard in discussion
    > In control group with no discussion it was 0%
    • Memory Contamination- co-witnesses so information is distorted and altered by combined misinformation
    • Memory Conformity- Gabert concluded witnesses go along with each other either due to NSI or ISI, actual memory unchanged
  • Eye Witness Testimonies: Misleading info evaluation
    + Real World Application, led to change in questioning of witnesses= improved legal system
    -Sutherland and Hayne 2001 showed ppts a video, asked misleading questions but recall was more accurate for central details then peripheral due to focus so they were resistant to Misleading Information. Not predicted by substitution explanation
    -Skagerberg and Wright 2008, showed ppts clips with minor changes, at recall ppts gave mix of 2 clips, suggests memory is distorted through contamination rather than memory conformity
  • Eye Witness Testimonies: Negative effect of anxiety (weapon focus)
    • Johnson and Scott 1976:
    > Ppts believed they were taking part of a lab study
    > In waiting room, low anxiety condition, heard casual conversation in the next room and saw man walk past with a greasy pen
    > High anxiety heard heated argument and saw a bloody knife
    > Ppts later picked man out from 50 photos, 49% from low anxiety did correctly, 33% accuracy in high anxiety
    > Tunnel theory leads to weapon focus
  • Eye Witness Testimonies: Positive effect of anxiety
    • Yuille and Cutshall 1986:
    > Actual shooting in Canada Gun Shop- owner shot the thief
    > 13/21 witnesses took part in the study
    > Interviewed 4-5 months after incident and compared to original police interviews taken at the time
    > Accuracy determined by number of details, witnesses also asked to rate stress at time and if they had emotional problems since
    > Very accurate with little change after 5 months, some details less accurate e.g. colours
    > Those with reported highest stress had 88% accuracy compared to 75% from low-stress group
  • Eye Witness Testimonies: Anxiety overall
    • Yerkes and Dodson 1908:
    > Relationship between emotional arousal and performance is an inverted U
    > Both overly high and low anxiety impair recall but there is an optimal level of anxiety where recall is best
  • Eye Witness Testimonies: Anxiety Evaluation
    -Pickel 1998, experiment with scissors, handgun, wallet or raw chicken as handheld items in hair salon video. Eye Witness Testimonies worse in high unusualness, Weapon focus may be due to unusualness not anxiety
  • Eye Witness Testimonies: Cognitive Interview
    • Fisher and Geiselman 1992:
    > Report everything
    > Reinstate context
    > Reverse order
    > Change perspective
    • Enhanced Cognitive Interview (Fisher et al 1987) includes social dynamics such as eye contact, reducing anxiety, slow speaking and open questions
  • Eye Witness Testimonies: Cognitive Interview Evaluation
    -Time consuming, need rapport with witness and extra training. Not realistic, may focus on few key elements. Also different police forces use different variations of the Cognitive Interview
    + Kohnken et al 1999, meta analysis of 55 studies comparing Cognitive Interviews to standard, 41% increase in accurate information with Cognitive Interviews, only 4 studies in analysis showed no difference. However also found an increase in inaccurate information recalled so evidence should be treated with caution