Cognitive Flashcards
Memory
The process by which we retain info about events that have happened in the past
STM Capacity
Very limited capacity 7 +/- 2 - Miller’s magic 7
LTM Capacity
Potentially unlimited = hard to measure
Millers Magic 7
Tested capacity of STM & found = 7 +/- 2 meaning in every day life we may only remember 7 numbers / letters
Digit Span Test
Jacob’s 1887
Given number of digits & Ptp asked to remember in order - inc by 1 digit each time until can no longer remember in order
= 443 females (8-19) North London collegiate school - mean digit span = 9.3 & letter span = 7.3
Strengths of Miller’s Magic 7
Theory is based on & supported by research e.g., Jacob’s
J’s research = based on systematic & replicable procedure - Digit span shown as reliable & valid by others
Weaknesses of Miller’s Magic 7
J’s research done in 1800s may not = well controlled - could be affected by confounding variables
M’s theory that ppl can remember as many chunks as letters = disproved - shorter span for longer chunks - Simon 1974
Cowan 2001 reviewed a variety of studies into STM & concluded it is likely to be limited to about 4 chunks
Some researchers have looked at STM capacity for visual info & 4 items = limit
M’s work based on others work may have made mistakes
Strengths of Jacob’s Study
Based on systematic & replicable procedure - shown to be r & v by others
In controlled environment & large num of ptps = gen to large group of ppl
Created objectifiable method
Weaknesses of Jacob’s study
May = IDs
Cannot be gen to rest of society only = young girls
May not have been well controlled like today - confounding variables
STM Duration
Limited 18-30 seconds
Most ppl keep info longer by rehearsing- repeating keeps memory active
LTM Duration
Unlimited theoretically whole life
Peterson & Peterson 1959 Procedure
Investigated probability of recalling info when rehearsal = prevented
Lab exper Repeated Measures 24 intro psych students at Indiana Uni
Ptp given a 3 letter trigram & a number to count back from in 3s / 4s when red light appeared recall = 3-18s
Peterson & Peterson 1959 Findings
As delay inc recall ability decreased
Verbal repetition prevents rehearsal from taking place so items being learnt = lost - lasted approx 18 secs
Peterson & Peterson 1959 Criticisms
Nonsense trigrams in a lab = low eco val
Relates to 1 aspect of memory & may not apply to all aspects (semantic, episodic & procedural)
Students aren’t like everyone else - clever & younger
Psych students may try to guess the aim may change behav - DCs
Single blind & double blind can combat
Research into STM Duration
STM = short duration - P&P suped by Sebrechts (1989) - Ptps asked to unexpectedly recall 3 words did well if recall = immediate after 4 = almost 0 - sups limited duration w/o rehearsal / processing
M recent research shows STM duration is not as P&P thought - Naire (1999) thinks can = 96 secs
Research into STM Duration Criticisms
In Naire’s study ptps were asked to recall the same items across trials earlier studies used dif items could lead to interference dec recall
Info remains in STM for quite a while unless overwritten / replaced
Bahrick Procedure
Aimed to investigate VLTM in a natural setting w/ personal significance - comp verbal & visual
Sample - 400 Ptp 17-74 various tests - year book used to ensure accuracy
1. Free recall names in grad class 2. Photo Rec 50 photos from their class 3. Name Rec x school friends
Bahrick Findings
Tested w/in 15 yrs = approx 90% accurate faces & names
After 48 = 80% for name & 70% for face
Free recall less good 15 yrs = 60% 48 = 30% - LTM lasts longer if visual than verbal as older free recall dec = harder to retrieve w/o stimulus
Bahrick Conclusions
Evidence of VLTM - some loss - verbal almost as good as visual - recog better than recall - need stimulating
Bahrick Criticisms
Could have looked at yearbook recently - could recall m info - may have met friends recently
Some may know m / some old have mem probs
Eco val not lab exper
Encoding
Initial learning of info = how info from sensory input is changed into a form it can be stored
E.g., a word seen may be stored is encoded into a sound / meaning
1st stage of process of memory involves processing info not same in LTM & STM
Visual Encoding
Images
Elaborative Encoding
Relating to prior knowledge
Tactile Encoding
Touch
Organisational Encoding
Categorising
Acoustic Encoding
Sound
Semantic Encoding
By meaning
Baddeley 1966
Aim: asses coding in STM (mainly acoustic) & LTM (mainly semantic)
Tested affects of acoustic & semantic similarity recall on 75 Ptp
4 groups given word list - either similar / dissimilar a / s
At recall found ptps had difficulty in remembering acoustically similar words in STM but not LTM
Semantically similar words easy for STM not LTM
Baddeley 1966 Strengths
Had controls to prevent extraneous variables from confounding results
Poor hearing could have affected - given hearing test only perfect = used
Took place under controlled conditions in lab = internal val
Baddeley 1966 Weaknesses
Used meaningless tasks & stimuli lacked eco val
Some experiments have also shown visual codes used in STM - Brandimore (1992) ptps used visual coding in STM if given visual tasks & prevented from rehearsal b4 recall
Normally we translate visual images into verbal codes but when rehearsal = prevented found to have used visual codes
MSM Forgetting
STM has a capacity of 7+/-2 units of info if = full info will become displaced (leads to forgetting)
STM has limited duration b4 it needs to be transferred to LTM if runs our info will decay (leads to forgetting)
Sensory Store
Iconic store - visual input - what we see
Echoic store - for auditory - what we hear
Haptic store - tactile input - what we touch
Baddeley 1988
Purpose of visual store is to allow us to integrate visual info we exper to = a smooth continuous visual exper
Have to hold SM info from 1 image during a few mili-sec it takes b4 next image is presented
Another func = sift incoming sensory info to avoid overload
SM holds image for a few seconds whilst scanned to decide when attention should go & passed for process
Sperling 1960
Ptps asked to stare at cross on screen - shown word grid for 50 milk seconds - asked to recall as many as possible could recall 4-5 aware of m
Change technique = 3 tones 1 for each row show grid & tone played immediately after - average recall = 3 - could have been any row but memory fades too quickly
While thing = 5 recalled (42%) but 1 row = 3 recalled (75%)
Sperling 1960 Evaluation
= reliable high control levels
May lack validity doesn’t reflect everyday memory use
Ethical issues = limited right to w/d & debrief = NB due to potential bad performance perception
Glanzer & Cunitz (1966)
Condition 1 immediate recall
Condition 2 distractor task
Serial Position Effect
Words better recalled from start - primary effect - words = rehearsed & transferred to LTM
Words better recalled from end - recency effect - in STM at start if recall
Middle = less recall
Glanzer & Cunitz (1966) Condition 2
distractor task disrupted recency effect - words from last part not recalled well = displaced in STM but earlier words not affected as rehearsal meant they had gone into LTM
Central Executive
Has overall control - sets task goals - Directs attention to task
Monitors & corrects errors
Starts rehearsal process
Determines how resources are allocated
Limited capacity = key component
Slave Systems
Support CE - can be used as storage systems
frees up CE capacity for m demanding tasks
Have separate responsibilities
Phonological Loop
Sometimes called inner voice - deals w/ auditory info & preserves word order - limited capacity
Baddeley (1986) subdivided into articulatory process (holds words heard / seen & silently repeats) & phonological store (inner ear holds words heard)
Visuo-spatial Sketchpad
Used when planning spatial tasks = limited capacity
Visual / spatial info stored
Subdivided - Logie (1995) passive visual store & visual cache
linked to inner scribe = rehearsal mechanism
Episodic Buffer
Baddeley added 2000 realised model needed general store - slave systems deal w/ specific info type
CE has no storage capacity = extra storage & integrates info from other areas
Baddeley & Hitch (1974) Positive Evaluation
M detail than MSM - dual task expert = used - struggled to complete 2 verbsl / visual tasks = limited capacity - when 1 verbal & 1 visual could complete = 2 stores
Brain damaged patients KF had visual STM X verbal capacity - suggests = 2 stores nut = unique & individualistic not gen
Baddeley & Hitch (1974) Negative Evaluation
Doesn’t describe LTM link - Cowan (1998) suggested that to explain abilities e.g., text comprehension WMM should have LTM activation - need LTM to understand STM
Some areas = vague & inaccurate some psychs = CE = too vague & doesn’t explain anything probs sev components (Shah & Miyake)
Doesn’t take into account other STM forms - Berz (1995) X musical memory - can listen to instrumental w/o impairing performance on other acoustic tasks
Types of LTM
Tulving (1985) = 1st to realise = 3 types & MSM = too simplistic & inflexible
Procedural LTM
non - declarative - knowing how
memory for task performance
e.g., walking
Semantic LTM
declarative - knowing that
memories for meaning, understanding & knowledge
Episodic LTM
declarative - knowing that
memory for events in individuals life
e.g., birthdays
Clive Wearing
had procedural & some semantic LTM
could play piano & had knowledge of edu system - no episodic
supports Tulving
Types of LTM Evaluation: Clive Wearing
clinical evidence - episodic LTM = greatly impaired as consequence of amnesia - had great dif past event but semantic = rela in tact - knew word meanings - procedural = intact could play piano etc
Types of LTM Evaluation: Corkin (1968)
studied HM - severe anterograde amnesia as result of op = unable to store new LTM but = taught new skill - initially performance = v poor gradually improv - tested sev days later & = able to perform as well - no knowledge of it
could make new procedural memories
Types of LTM Evaluation: Brain scan Evidence
Tulving (1989) injected self w/ radio active gold - tracked w/ scanner - historical facts blood flow inc at back but childhood expers blood flow at front
but = one person not gen shows dif forms = sep
Types of LTM Evaluation: Tulving (1994)
got ptps to perform dif tasks & scanned brain w/ PET scan - found episodic = right PFC & semantic in left PFC procedural = cerebellum & basal ganglia
= m gen inc pop val = m specific but semantic found in dif place - no DCs
Types of LTM Evaluation: Cohen & Squire (1980)
argue only 2 types of LTM - accept procedural as 1 type but argue semantic & episodic = stored together in declarative memory = consciously recalled & procedural = non declarative & unconsciously recalled T sup w/ PET scan
Trace Decay (STM)
idea info = physically reped as memory trace = fragile & disintegrates if not constantly refreshed after about 20s decayed completely & recall not pos
Displacement (STM)
STM = lim cap if full then some existing info = pushed out / overwritten
Interference
1 memory disturbs the ability to recall another - can result in forgetting / distorting a memory 1 / both likely if similar
Pro-Active Interference
previously learnt info interferes w/ new info you = trying to store e.g., new class names muddled w/ old
Retro-Active Interference
new memory interferes w/ older ones e.g., can’t remember old class names only new ones
Research Into Affects of Similarity
McGeoch & McDonald (1931) studied retro active by changing amount of sim between 2 sets of materials - learnt list of 10 words until 100% accuracy then = new list = 6 groups: 1. synonyms 2. antonyms 3. unrelated to OG 4. consonant syllables 5. 3 digit nums 6. control
McGeoch & McDonald (1931) Findings
when asked to recall OG list most sim - syns = worst recall - interference when = sim
Evaluation of Interference: Baddeley & Hitch (1977)
asked rugby players to recall names of teams had played - all played same time interval nut some num of intervening games varied due to injury - m games = poorest recall = high val
Evaluation of Interference: Limitation of B&H
interference can = temp can be overcome by cues
Tulving & Psotka (1977) gave ptps list of words in categories 1 at time not told categories - recall = 70% 1st list but = worse as add new list (pro I) but when given categories (cues) recall inc 70% = temp - not in theory
Evaluation of Interference: Lab Studies
m sup evidence = lab studies good control of EVs = replicable & reliable but = artificial material = meaningless doesn’t rep everyday life - B&H
not same motivation to remember stimuli in exper recall may dec and effects seem stronger
Evaluation of Interference: Cesaro (1967)
if tested again (24hrs later) = dig recovery may = temp
Tulving’s Encoding Specificity Principle
reviewed research into retrieval failure & discovered a consistent pattern - ESP = if cue = helpful must = present at encoding & retrieval if dif may forget
Cue Dependent Forgetting
forgetting due to lack of cues
context & state
Context Depending Forgetting
Golden & Baddeley (1975) divers learnt list of words underwater / on land & then asked to recall on land / underwater = 4 conditions - 40% lower recall in non matching conditions
Context Depending Forgetting Evaluation:
limited eco val = familiar environ X task = artificial
groups in dif environ = disrupted could have influ
= controlled - reliability = testable
dif to disprove - circular arg
doesn’t consider meaning / motivation
used to improv eye witness testimony
Context Depending Forgetting Evaluation: Abernathy (1940)
students perform better in tasks if in same room as material learnt & if same instructor
State Depending Forgetting
when mood / physiological state during recall = dif from mood learnt in
Godwin et al (1969) 48 medical students ptped in 1 day training session & 2nd day test 4 groups = 1. S&S 2. A&A 3. S&A 4.A&S - A = 100 ml of alcohol in blood show signs of intox = 4 tasks 1. avoidance task 2. verbal rote learning 3. word assoc 4. pic recog m errors in AS & SA than AA & SS but not for pic SS = best
State Depending Forgetting Evaluation:
limited eco val tasks = artificial
DCs dif to disprove - cir arg X meaning / motivation
high control can be replicated & reliably tested
used to improv EW testi
State Depending Forgetting Evaluation: Overton (1964)
experimented on 2 groups of rates 1 given mild barbiturate & put in maze & taught to escape electric shock
when drug group not drugged couldn’t escape if given shocks could - not influ by DCs
Loftus & Palmer (1974)
Eye Witness Testimony - Misleading Info
aim: investigating leading q affect on mem of event = lab experts & indepen g’s IV: verb DV: esti speed 45 students
7 dif films of traffic accident - given q had to describe & answer specific q’s - How fast were the cars going when they hit/smashed/bumped/contacted/collided?
mean speed = smash: 40.8 col: 39.3 bump: 38.1 hit 34 con: 31.8
Response Bias Explanation
? wording has no effect on meme just how they decide to answer - when get leading ? e.g., “smashed” encours higher esti
Substitution Hypothesis
wording changes men - heard “smashed” later inc likelihood to say saw broken glass than if search hit - L&P
Positives of Lab Experiments
high control results due to IV not CVs
cause & effect - IV affected DV ie dif words = dif recall
Negatives of Lab Experiments
low eco val doesn’t have emo impact as real incident - know something is happening can pay attention
DCs - Zaragosa & MsCloskey (1989) argue many answers pops Gove in LS’s of EWT = result of DCs want to appear useful so guess
Consequence of EWT
Foster et al (1994) what you remember as EW can have some v NB consequences not true in studies
Further Research: EWT - Misleading Info
using red wallet exper Loftus concluded it = mainly peripheral info that = unreliable & can be tampered w/ paps = shown man stealing large red wallet - 98% correctly identified colour - late read brown - unlikely to change other things did
Individual Differences: EWT - Misleading Info
evidence for older = less accurate e.g., Anastasi & Rhodes (2006) found ppl 18-25 & 35-45 = m accurate that 55-78 but all m accurate when identifying own age group (own age bias) research studies use younger ppl as target - may mean some age groups not less accurate
Schemas
mental framework of beliefs & expectations that influ cognitive processing - developed from exper helps process info quickly
Personal Schemas
about specific person e.g., my friend always bites her nails
Social Schemas
how ppl behave in situs e.g., must queue at checkout
Self Schemas
focused on knowledge of yourself e.g., I tend to talk to fast
Event Schemas
focused on patterns of behaviour after specific event e.g., bell rings students pack up
Post Event Discussion
when EWs discuss a crime they have witnessed testimonies become contaminated - combine info from own & others mem = m inaccurate
Loftus & Pickrell (2003)
suggested to ptps that they had met Bugs Bunny at Disney yrs earlier = impossible
Source Monitoring Theory
mems of event = genuinely distorted - EW can recall info about event (accurate & inaccurate) but can’t recall where came from - source confusion
Conformity Theory
EW mems not actually distorted - only appears to change bc go along w/ account of co-witnesses for soc approval / think others = correct
Gabbert et al (2003)
supports Post Event Discussion
ptps in pairs each watch video of crime on own = same crime but 2 dif POVs 1 could see elements other couldn’t then discuss
DV = recall of crime
Gabbert et al (2003) Findings
showed 71% of ptps mistakenly recalled aspects of crime they couldn’t see but picked up from discussion
control group - no PED - recalled 0% of things they couldn’t see = mem conformity - ptp goes along w/ other witness
Positive Impact of Anxiety on Eye Witness Testimony
stress of witnessing crime creates anxiety through physiological arousal - triggers f/f inc alertness & ensuring we pay attention improving mem of event
Positive Impact of Anxiety Evaluation
Yuille & Cutshall (1986) showed EWs of real life incident had remarkable accurate mem of stressful & anxious event involving weapons - recalled accurate, detailed info = corrob by others despite police’s leading questions - suggests anxiety can = detailed & accurate
Weapon Focus Effect
anxiety caused by seeing a weapon focuses all attention on weapon as a source of danger
Stress & Eye Witness Testimony
frightening situs may affect recall performance bc of stress
Supporting Weapon Focus Effect
Loftus et al (1987) reported on study by Johnson & Scott (1976) ptps heard discussion in another room 1. ptps saw man emerge holding pen w/ greasy hands 2. knife & bloody hands (high anxiety) when asked to identify man from 50 photos found 1. = 49% & 2. = 33%
weapon may have distracted & Loftus found when tracked eye movement = drawn to weapon & away from person’s face
Negative Impact of Anxiety Evaluation
Yuille & Cutshall (1986)
may be surprise not anxiety - Pickel (1998) in hairdressers = 1. scissors 2. wallet 3. raw chicken 4. hand gun accuracy = lower for chicken & gun = high unusualness - not specifically about anxiety
Stress & EWT Evaluation
Peters (1988) tested ptp who were attending local health clinic for injection met researcher & nurse for equal amount of time & week later asked to identify both recalled researcher better - anxiety impacted mem
Clifford & Scott (1978) found ppl who saw violent film attack remembered fewer of 40 items than control group who saw less violent version - X affect on recall
Explaining Contradicting Influence
Yerkes-Dodson Curve / Law (1908) performance (mem/recall) = best in mod arousing (stressful) conditions e.g., taking part in an exper - too little not enough attention to inc so can’t concentrate
Yerkes-Dodson Curve / Law (1908)
Deffenbacher (1983) reviewed 21 studies & hypothesised stress & performance follow inverted U curve if have too much anxiety mem = adversely affected
Fisher & Geiseln (1992)
reviewed mem lit - recall better w/ cues created cog interview - useful techniques
Reverse Order (RO)
report episode in sev dif temporal orders backwards & forwards - prevents expectations & lying
Changed Perspective (CP)
recall from sev POVs imagining how others would have seen crime - disrupts expectations, schemas & lying
Report Everything (RE)
report every single detail even if trivial / unsure may = NB / trigger other mems
Context Reinstatement (CR)
mentally recreate environment recall scene weather thoughts feelings & preceding events relates to context depen forgetting
Enhanced Cognitive Interview
Fisher et al (1987)
- minimise distractions
- avoid interruption
- actively listen
- encourage imagery
- ask open ended questions
- adapt lang to EW
- pause after response
- avoid judgmental coms
Kohnken et al (1999)
meta analysis of 53 studies found average of 34% inc in amount of correct info gen inc pop val (ma) but used samples of uni students dec pop val = lab exper dec eco val
Milne & Bull (2002)
effectiveness of 4 components of CI in undergrads & children comp to control lab exper recall = sim across all 4 compos & no dif to control found RE & CR = best lacks eco val = lab
Fisher et al (1990)
real police setting Miami trained POs in enhanced CI techniques w/ real EWs sig enhance amount of recall only 1 cul
Stein & Memon (2006)
comp normal interview technique & CI in Brazil and CI inc amount & detail of info has val cross cut
Kebbel et al (1999)
survey in UK of POs widespread use of CI but although found useful = concerned about amount of X info gen & time taken to interview use RE & CR but rarely CP & RO
Cognitive Interview Evaluation: Time Consuming
time consuming to train & = costly Mermon et al detective who had brief training session (4hrs) did produce sig inc in info - Econ implication takes long training to = effective
Cognitive Interview Evaluation: Controls
hard to evaluate many versions some p forces use some / all = dif to control all variables
