Cognitive Psychology

Capacity: refers to the storage space in each type of memory (STM 7 (+-2), LTM unlimited)

Key Study - Miller STM

• tested his theory of the 'magic 7' that could be remembered in STM
• started with 3 digits and asked to read back to him immediately, increased by 1 digit each time until recall was accurate on 50% of trials
• rule of 7 (+-2) applies to letters and numbers

Evaluation:

• individual differences - memory improves with age but deteriorates into old age, physical/health issues, IQ
• generalisability - lacks mundane realism, lacks eco valid

Duration: refers to how long information lasts in each type of memory (STM up to 1.5 mins, LTM up to a lifetime)

STM - Peterson and Peterson

• trigrams of consonants (e.g. TKB) - trigrams chosen so that words were not made, important that stimuli were meaningless so that p's couldn't draw on LTM
• trigram presented then number, p's counted down immediately in 3's to prevent them rehearsing the trigram
• counting stopped after a retention interval of 0, 3, 6, 9, 12, 15 or 18 seconds
• 80% correctly recalled after 3, 30% after 9 and 10% after 18
• ev - replicable, lacks pop valid, repeated measures = order effect

LTM - Bahrick

• year book, from 2 weeks from grad to 57 years after grad
• 6 conditions: free recall of names and naming pictures (both steady decline) and recognition of names, recognition of pictures, matching pictures to names and names to pictures (remained high)
• ev - individual diffs, extraneous variables, large sample size

Encoding: information has to be converted into a different form for it to be remembered (acoustic, visual, semantic)

Baddely - LTM

• compares acoustic and semantic encoding
• showed p's lists of words that were either acoustically similar or semantically similar
• found that p's had difficulty remembering acoustically similar words in STM but not in LTM
• whereas semantically similar words were recalled more accurately in STM rather than LTM
• concluded that STM encoded acoustically so when we recall info from STM similar sounding words get confused, LTM encoded semantically.

Evaluation:

• lack pop validity - 70 young servicemen
• independent groups - no order effect, p variables may affect results
• lacks mundane realism - not everyday task to remember list of words

sensory >(attention)> STM (maintenance rehearsal/decay) >(elaborative rehearsal)> LTM <(retrieval)<

strengths:

• produces predictions that can be tested scientifically
• research support: brain scan studies show that different areas of the brain are active during STM (prefrontal cortex) and LTM (hippocampus) tasks - shows existance of seperate stores

weaknesses:

• oversimplified representation of memory - Spiers found that amnesiacs procedural LTM was intact but other aspects such as semantic and episodic memory were not

central executive: allocates attention to other systems, also acts as a temp store for all types of info - 'big boss'

visuo-spatial sketch pad: 'inner eye' - mentally walking around your house

phonological loop: consists of articulatory control process and phonological store

• articulatory control process - 'inner voice' - holds words we are preparing to speak
• phonological store - 'inner ear' - stores auditory infromation as an acoustic code

episodic buffer: integrates info from central exec and LTM

Attention:

visual and acoustic = yes

acoustic and acoustic/ visual and visual = no

:) - KF case study - shows STM works independantly of LTM, also his visual STM was better than auditory STM - shows seperate visual and auditory systems as predicted by phonological loop and visuo-spatial sketchpad --> criticisms for case study weaken support = lacks generalisability, no before and after comparisons (unethical to conduct experiment and give someone brain damage)

:) better explanation of STM than MSM - gives more detail and breaks down into substores - Park et al - problems with working memory help to identify patients with schiz and help with diagnosis

:( - not a complete explanation of memory - LTM is neglected - however that may have their intention in the first place

:( central executive - very vague and may be oversimplified - case study TVR - could use logical reasoning but couldn't make basic decisions - suggests C.E isn't one unitary component

loftus and palmer - 1st experiment

• 45 p's used
• how fast was the car driving when it (smashed, collided, bumped, hit, contacted) the other car?
• smashed = 40.8, contacted = 31.8
• misleading info affects the way memory was stored or retrieved

2nd experiment

• 150 p's shown film of accident and asked to estimate speed when they smashed/hit into each other
• 1 week later, asked to recall whether there was broken glass
• no broken glass but 16/50 who heard smashed thought there was, compared to 7/50 'hit'
• misleading info affects the way in which memory is stored

evaluation:

• students used as p's (young? less driving experience?) - standarised procedures, lack mundane realism (watching video closely, different emotions in real life) - low eco valid

Yuille & Cutshall

• robbery of gunstore (naturally occuring event) - robber was shot and killed in Vancouver
• 21 witnesses interviewed by police 48 hours after, 13 interviewed by researchers 4-5 months after
• witnesses who were more upset were more accurate - higher anxiety = better accuracy EWT

Christianson & Hubinette

• analysed testimonies from 58/110 witnesses of bank robberies in Stockholm - Sweden
• no effect of self reported anxiety - anxiety plays no affect in EWT

Loftus (weapon focus)

• p's overheard argument - cond 1 = man emerged with pen and greasy hands, cond 2 = man emerged with a paper knife and 'blood'
• p's identified man from 50 photos
• low anxiety cond 1 = 49% correct identification, high anxiety cond 2 = 33% correct
• lower anxiety = higher accuracy

Yarney

• adults spoke to young woman - they were asked to recall what she looked like
• older adults less confident but not less accurate - no differences with accuracy

Memon et al

• when delay between incidence and identification was short = no difference in accuracy between older and younger p's
• when identification delayed by one week = older witnesses significantly less accurate

Anastasi and Rhodes

• 3 age groups - young, middle aged and older
• shown 24 pics (8 of each age group) - then picked 24 out of 48
• elderly less accurate and own age bias

Parker and Carranza

• small children + college students, identification task, small children less accurate

:( own age bias - age of people in target pics may affect how many pictures each age range remember

:( all studies natural experiments, therefore may be extraneous variables affecting results

:( ecological validity of experiments, may increase demand characteristics

components:

• report everything: even if it seems irrelevant, based on idea that if there are similarities between memory and actual incident, there is an increased likelihood that witnesses will recall more details and be more accurate in recall
• mental reinstatement of original context: mentally recreate the scene, inc sounds, weather etc - increase details and accuracy
• changing the order: interviewer will try alternative ways through timeline of incident - Gieselman and Fisher suggest that recent events will be more accurately recalled than further in past
• changing the perspective: witnesses describe what other witnesses might have seen - can help them think about the event in ways which may enrich their recall

enhanced cognitive interview:

• original 4 + 
• build rapport (trust) 
• encourage extra effort and concentration

:) Holliday - increased accuracy in recall when used with children, therefore appropriate for children

:) Gieselman: 1) 66 student p's - staged testimonies were more reliable when questioned with CI technique, 2) 89 students - shown police training video, 48 hours later interviewed with CI or standard, no difference in errors, correct items recalled more in CI

:( studied lack ecological validity - findings may not generalise to real life situations

:( students as p's, age may affect EWT accuracy - can't generalise, of similar intelligence

:) real life studies e.g. Fisher - 47% more info recalled with CI

• verbal: acronyms, acrostics, rhymes, chunking
• visual: method of loci, keyword picture technique, mind mapping

how they increase recall:

• organisation - structured store allows more efficient location of info
• elaborative rehearsal - processing at deeper level, creating images
• dual coding hypothesis - using both visual and acoustic encoding

Bower: when mentally recreating an image for words, this increases recall to 80% whereas if just remembering the word, recall is only 45% - supports visual techniques

Craik and Tulving: the more deeply information is processed (semantically) the better recall will be - supports all memory techniques

:) control, standardised procedures, replicability, reliability

:( ecological validity, demand characteristics