evaluations Flashcards
coding in short term and long term memory
● strengths:
p: identified a clear difference between two memory stores
e: baddeley identified that STM - mostly coded acoustically, LTM - mostly coded semantically, suggesting that we all have a separate STM and LTM store
c: this is useful - led to development of the multi-store model of memory, which helped our further knowledge of memory
● limitations:
p: task lacked ecological validity
e: words used in study had no personal meaning to the participant - tells us little about coding for everyday memory tasks
for example, when processing more meaningful information, people may use semantic coding even for STM
c: matters as findings of study have limited application and can not be generalised to coding of memory in real life situations
capacity of short term and long term memory
● strengths:
p: miller’s research has real life application
e: chunking - used to help people info in STM day-to-day e.g. phone numbers. we don’t remember them as a long list of digits, instead we group them together to make them easier to remember
c: matters as research can help increase capacity of STM in real life
● limitations:
p: miller’s may have overestimated STM capacity
e: cowen reviewed other research - concluded capacity of STM is only about 4 +/-1 chunks
c: suggests lower end of miller’s estimate (5 items) is more appropriate than 7 items
duration of short term and long term memory
● strengths:
p: bahrick’s research - high in ecological validity
e: everyday meaningful memories (e.g. peoples faces and names) were studied
lab studies - meaningless pictures to be remembered - recall rates lower
c: bahrick’s research reflects a more ‘real’ estimate on duration of LTM
p: bahrick’s research - less control over extraneous variables
E: participants may have look at yearbook photos and rehearsed their memory over the years, strengthening their LTM
C; therefore, study may not provide completely valid picture of duration of LTM without rehearsal
● limitations:
p: peterson and peterson’s method is artificial
e: although we sometimes remember meaningless things in life, recall of consonant trigrams does not reflect meaningful everyday memory tasks
also, in real life - often able to rehearse information
c: study lacks ecological validity - may not generalise to duration of STM in everyday situations
we may remember for longer irl than this study suggests
multi-store model of memory
● strengths:
p: supported by case study of HM
e: HM left with severe memory impairments after brain surgery - unable to store any new info in LTM - however, he performed well on tests of immediate memory span, a measure of STM
c: case study suggest STM and LTM are separate independent stores (as stated by MSM)
p: research support for features of STM and LTM stores
e: research evidence (using controlled lab experiments that have been replicated many times) to show STM and LTM have different capacities, durations and coding
e.g. baddeley’s study showed that coding in STM is acoustic but in LTM it is semantic
c: suggest that model is correct that STM and LTM are indeed separate and independent stores that must share information with each other
counter: artificial stimuli is used e.g. trigrams (meaningless). Therefore, research into MSM lacks ecological validity - MSM may not be good explanation of how memory works in everyday lives (where more meaningful info is often remembered)
● limitations:
p: case study of KF
e: researchers studied KF who had amnesia. KF’s STM for digits was very poor when they were read out loud to him
however, his recall was much better when he read the digits to himself
c: criticises the MSM as model states - only 1 type of STM (unitary store) - if this was case, then it shouldn’t have mattered if he heard them or read them himself - he should’ve been equally poor
suggest may be more than 1 type of STM (as stated by WMM)
counter: no control over what happened to patient before they experienced injury, therefore, no way of knowing what memory was like before(is it much worse?). so, conclusions researchers have reached about memory based on clinical studies may not be valid
types of long term memory
● strengths:
p: case study evidence supporting existence of different types of LTM
e: HM left with severe memory impairments after brain surgery. HM’s episodic memory had been damaged whereas his semantic and procedural are still in tact
c: supports view that there are different memory stores in LTM because store can be damaged but other stores are unaffected. of the MSM were true, all of HM’s LTM should be damaged but this is not the case
counter: issue with using case studies of individuals with brain injuries is researchers lack control in clinical case studies as they do not know anything about person’s memory before brain damage
therefore, clinical studies are limited in what they could tell us about LTM
p: understanding LTM allows psychologists to help people with memory problems, giving us real world application
e: memory loss in old age - specific to episodic memory. therefore, should be targeted to improve memory. belleville et al - devised intervention for older people targeting episodic memory - improved memory compared to a control group
c: distinguishing between different types of LTM enables specific treatments to be developed - improving individuals memory and qol
● limitations:
p: conflicting research findings linking LTM to areas of brain
e: buckner and peterson reviewed evidence regarding location of semantic and episodic memory - concluded semantic memory located on left side of prefrontal cortex and episodic memory on left. however other research contradicts this - suggests left and right prefrontal cortex both linked to encoding and retrieval of episodic memory
c: matters because challenges any neurophysiological evidence to support types of memory as there is poor agreement on where each type may be located
working memory model
● strengths:
p: support from PET scans
e: braver et al - gave participants brain scan - whilst scanning, asked to complete tasks involving central executive. found high activity in left prefrontal cortex. also found activity in this area increased as task became harder / more demanding
c: strength as findings supports wmm - shows that there is biologically based evidence to support different components of the vmm. also supports models prediction that there will be more activity in CE as more demands are placed upon it, as reflected in greater brain activity
p: support from case studies - K.F
e: shallice and warrington studied client - K.F - had clinical memory disorder called amnesia. K.F’s STM for digits was very poor when read outloud to him. however his recall much better when he read the digits to himself
c: strength as supports wmm as suggests may be more than 1 type of STM. if there was only 1 type of STM store - shouldn’t matter if he heard them read or read them himself - he should have been equally poor
counter: however, problem with using case studies of individuals with unexpected brain injuries is that there’s no control over what happened to patient before injury. therefore, no way of knowing what memory was like before (is it much worse?). so, conclusions researchers have reached about memory based on clinical studies may not be valid
● limitations:
p: psychologists know very little about the central executive
e: argued that info we have on this component - very limited. all baddeley and hitch state is that capacity is limited and it controls other slave systems, but we don’t know more than this. Identified this as being the most important aspect in the wmm but it’s the part we know the least about
C: limitation as wmm can be criticized for giving details on all other sections of the model but not fully explaining its most important part. therefore, could be said to be incomplete theory - lacking detail into the true complexity of STM
experimental evidence for the working memory model: the duel task method
● strengths:
p: one strength of wmm is that studies of dual task performance support separate existence of visuo-spatial sketchpad
e: for example, baddeley et al found participants had more difficulty completing 2 or more verbal tasks together, compared to completing a visual and verbal task at same time. this is because both tasks compete with same subsystem (VSS), whereas no competition with a visual and verbal task
c: strength as supports wmm because suggests there must be separate subsystem that processes visual info in STM and also a separate system for verbal processes, which wmm suggests (vss and phonological loop)
interference theory
● strengths:
p: research evidence from mcgeoch and mcdonald
e: for example, participants given 10 words to learn until they had 100% accurate recall of list. then, split into 6 groups and each group given a second list to learn: synonyms, antonyms, unrelated words, nonsense syllables, 3 digit numbers or no new list, just rest. found group recalling similar words had a lower mean number of words recalled from original list(1.2), whereas, group at rest had much higher mean number of words recalled from original list (4.4)
c: strength as supports retroactive interference - newer info caused forgetting of original list - and interference was strongest the more similar info was to original
counter
p: issue with many studies investigating interference theory - lack ecological validity
e: for example, tasks often require p’s to learn list of meaningless words, objects, etc. then soon after recall all / part - leaving relatively short amount of time between learning and recall. irl, we often learn something then recall it a long time later (e.g. revising for an exam)
c: limitation as most everyday forgetting many be explained better by other theories, rather than interference theory (e.g. retrieval failure due to lack of cues)
p: research evidence from baddeley and hitch in a more everyday situation
e: for example, asked rugby players to name teams they had played so far in season. found that accurate recall did not depend on how long matches took place but more importantly was number of games they played in meantime (more interference)
c: strength as shows interference operates in some everyday situations, increasing ecological validity of theory
counter: however, lack of control of extraneous variables in this study - we can not conclude that interference caused difficulties with remembering the team names
retrieval failure
● strengths:
p: research support for context dependant forgetting
e: for example, godden and baddeley conducted study on under water divers - given list of words either on land or underwater - then had to recall words either on land or underwater. In conditions where learning and recall matched (e.g. learn on land and recall on land) recall higher by 40% than when the conditions did not match (e.g. learn on land and recall underwater)
c: suggests that retrieval failure was due to lack of encoded context cues at time of recall, meaning that material was forgotten
p: also, research support for state dependant forgetting
e: carter and cassidy conducted study of people who suffered with hay fever - gave their participants mild anti-histamine - made them feel drowsy. then, given list of words to learn either on drug or not - then had to recall words either on drug or not. in conditions where there was a mismatch between internal states at learning and recall (e.g. learn on drug - recall when not on it), performance on memory test was significantly worse
c: shows that when state cues present at encoding are absent at retrieval (e.g. drowsy when recalling, alert when encoding), then there is more forgetting
p: though some of research in this area lacks ecological validity - there are still important implications to everyday memory
e: abernethy found that students recalled more information when tested in same room with same teacher, in comparison to students tested in different room with different teacher - supports idea that learning and testing in same environment prevents forgetting to some degree
c: matters because shows retrieval failure can be applicable to help students with their examinations in everyday life - if students learnt and recalled in the same exam room, this would be advantageous
● limitations:
p: not always reflective of real life forgetting
e: this is because many psychologists have argued that when retrieval failure (both context and state dependant) is studied in experiments - results indicate a far stronger forgetting effect that we experience in our everyday life. this is because of the vastly different states or context used in studies (e.g. baddeley’s underwater vs on land)
c: limitation as it means retrieval failure due to lack of contextual cues may not explain much about everyday forgetting
leading questions
● limitations:
p: research mostly conducted in lab - lacking ecological validity
e: for example, loftus and palmer asked p’s to watch video clips of car accidents - rather than witnessing real crime. irl, p’s would experience high anxiety if witnessing a crime - emotions can not be replicated in a lab setting
c: limitation as studies that use such artificial tasks may tell us very little about how leading questions and p-e discussion affect EWT in case of real accidents or crimes, limiting usefulness of practical applications
p: weakness of research into effects of misleading question is many answers given by participants - actually due to demand characteristics
e: p’s aware the are taking part in research study - therefore, may want to please researcher and appear helpful. for example, p’s in loftus and palmers study may pay close attention to video clips to try and accurately guess speed
c: limitation as reduces internal validity of EWT - results may be due to demand characteristics rather than leading questions
p: results may be affected by individual differences
e: even though loftus and palmer was a lab experiment - extraneous variables (age) may account for results shown in studies
anastasi and rhodes found that older people were less accurate than younger people at giving eye witness reports
c: all of loftus and palmers p’s were students - difficult to generalise results of students to the whole population - as other ages may produce different results (and have different accuracies in EWT)
post-event discussion
● strength:
p: research support
e: gabbert et al - compared participants together who both watch video of same crime but from different angles. then, they discussed what they’d seen before giving them recall test
71% of participants mistakenly recalled aspects of event that they could not have seen
in control group (no discussion) - no errors in recall
c: supports idea that P-ED can have negative impact on EWT - either through memory contamination or memory conformity
counter: lacks validity - participants may have paid extra attention to video clip to remember more detail about crime and to please researcher. irl, may not be able to pay close attention to crime (might not know it’s about to happen)
overall evaluation of misleading information
● strength:
p: research into misleading info has real-life application within criminal justice system
e: leading questions: consequences of inaccurate EWT are serious - loftus argues police officers should be careful in phrases questions to witnesses due to distorting effects
post-event discussion: police officers should take measures to prevent P-ED such as interviewing individuals in separate time slots with separate waiting areas - to avoid discussion
c: matters because psychologists can improve how legal system works and protect the innocent from faulty convictions based on inaccurate EWT - also, research led to development of cognitive interview which proven to improve EWT
the cognitive interview
● strengths:
p: evidence in support of the effectiveness of the cognitive interview
e: researchers conducted meta-analysis of 50 studies - finding that enhanced CI consistently provided more correct information during recall than standard police interviews
c: shows CI is effective in helping witnesses recall info that is valuable but not accessible
research shows that it gives police greater chance of catching and charging criminals which is beneficial to society as a whole
counter
p: increases amount of inaccurate info, as well as accurate info
e: researchers found 81% increase in incorrect info but also 61% increase in incorrect info when CI was used compared to a standard interview
c: therefore - warns us not all info produced in CI is likely to be accurate - if all info seen as accurate, then false convictions may occur
● limitations:
p: not all of its elements are equally effective or useful
e: researchers found that, although all 4 elements were valuable, a combo of ‘recall everything’ and ‘context reinstatement’ produced best recall
c: therefore, cast doubts on credibility of overall CI because some techniques less effective than others
p: police officers may be reluctant to use CI because it takes more time and training than standard police interview
e: for example, more time needed to build relationship with witness so they feel relaxed. Police must also undertake special training before technique is used, since police training to use CI takes time and money, many police forces choose to not have officers trained - or only send them for a few basic hours training due to cost
c: limitation as police may not be properly trained to illicit accurate EWT, meaning some guilty suspects may not be identified and charged. therefore, may be better to just focus on few elements that are more effective in enhancing recall - such as ‘report everything’
