Internal: Flashcards
conrad:
1964
-aim: to see how information is encoding in STM
-procedure:
-showed participants a random series of 6 consonants and asked them to remember them
-there were two conditions: acoustically similar (P,D,T) and acoustically dissimilar words (D,O)
-participants had to write them down in order
-findings: participants made frequent errors of recall, they also found out it hard to recall strings of letters that sounded similar. It was therefore concluded that STM is encoded phonologically
Conrad: evaluation
Strength:
-the idea that STM is encoded acoustically is supported by Baddeley 1966
Weaknesses:
-lacks realism: the use of single letters does not compromise a reflection of the memory tasks we encounter in everday life
-other methods of encoding, such as visual (or even taste and smell) are also used
baddeley:
1966
-aim: to test whether LTM was encoded acoustically or semantically
-procedure:
-participants were provided with different word lists that either sounded similar or meant similar things
-the 72 participants were recruited through opportunity sampling and were randomly allocated to four groups
-predictions:
-if participants could remember more similar-sounding words, LTM would be encoded acoustically
-on the contrary, if participants remembered more words with similar meanings, LTM would be encoded semantically
-the IV had two levels: 1. Acoustically similar words vs. Acoustically dissimilar words, 2. Semantically similar words vs, semantically dissimilar ones
-the DV was the score on a recall test of 10 words, participants had to recall the words in the order they were presented
Baddeley 1966: different phases
-the learning phase was seperated from the testing phase by an interference test in which participants had to hear and write numbers
-in the testing phase, participants took part in a recall test
-for the recall test, participants needed to recall the words and the order in which they appeared
-this procedure was repeated four times, after the fourth trial, participants took a break and completed an unrelated interference task
-to their surprise, they were aked to recall the list of words again after the break
Baddeley 1966: findings
-when calculating the results, the performance of the individuals in groups 1 and 2 was compared, as well as the performance of groups 3 and 4, seperately
-further, participants’ peformance on the 5th trial was analysed to test for forgetting
-the results indicated that:
-acoustically similar words were harder to recall than acoustically dissimilar words, remembering the words cap, hat, and sack is more difficult than remembering cow, dad and led
-semantically similar words were harder to recall than semantically dissimilar words, remembering the words big, large, and huge is more difficult than remembering hot, pen, and man
-when assessing STM, this is when comparing trials before the break, the worse performance was for the acoustically similar words
-performance was overall better on the semantic condition than on the acoustic one
Baddeley 1966: conclusion
-the main conclusion that Baddeley drew from such results is that LTM is encoded semantically
-this comes from the fact that performance on the 5th condition was better for the semantic condition than for the acoustic one
-further, Baddeley (1966) concluded that STM is encoded acoustically
-this was deduced by the fact that performance on the short-term conditions (trials 1-3) was worse for semantically similar words
Repeated measures design: definition and example study
-a type of experimental design where the same subjects are used for each treatment or condition
-example study:
-Loftus conducted a study that used a r.m.d to explore how the information presented after an avent can alter a person’s memory of that event
-participants views a car crash video and then asked misleading questions
-this design was appropiate since it allowed her to control indidivdual differences, measure how memories change over time and increase statistical power by comparing responses from the same participants under different conditions
-demonstrated how post-event information can alter people’s memories of an event
Repeated measure design: advantages and disadvantages
advantages:
-increased statistical power -> reduces variability
-fewer participants needed -> more cost-effective
-control of condounding variables -> enhances internal validity by using same participants
-ability to track changes over time -> observes chamges within individuals across conditions
disadvantages:
-order effects (practice, fatigue) -> treatment order can influence results
-carryover effects -> previous treatments can affect responses in subsequent treatments
-participant attrition -> dropout can complicate results due to intertwined data
Primary-Recency effect: seperate definitions
-primacy effect: the items at the start of the list are more likely to be transferred to our long-term memory due to repeated rehearsal
-recency effect: the items at the end of the list are still in short-term memory when recall is promptly
Primary-Recency effect: information
-> the tendency to remember the first (primary) and last (rencency) items in a list, while forgetting those in the middle
-reasons: cognitive processess -> primacy and recency effect (other defs.) + memory -> primacy linked to long-term memory; recency linked to short-term memory
real life observations:
-shopping lists
-presentations
-job interviews
-exams
-everyday conversations
-application: understanding this effect can help structure information for imporved retention and recall
Glanzer and Cunitz: overview
-1966
-investifated the serial position effect, specificially the primacy recency effect in memory recall
-key concepts -> primacy effect + recency effect
Glanzer and Cunitz: method
-participants were presented with lists or words and were asked to recall them immediately after presentation
-the study varied the timing of the recall:
-immediate recall (no delay)
-delayed recall (participants counted backwards for 30 seconds before recalling)
Glanzer and Cunitz: findings
Immediate recall:
-participants showed both primacy and recency effects; they remembered the first and last items best
delayed recall:
-the recency effect dimisnhed significantly after a delay (due to the displacement of stm)
-the primacy effect remained relatively intact, supporting the idea that early items were stored in long-term memory
Glanzer and Cunitz: conclusions
-the results supported the multi-store model of memory, indicating that stm accounts for the recency effect, while ltm accounts for primacy effect
-the study highlighted the distinct processes involved in memory retention and retrieval
what is the multi-store model of memory?
-the multi-store model of memory is the most well-known and influential model of memory, proposed by Atkinson and Shiffrin in 1968
-they saw memory as a flow of information through a system of interacting memory stores
-each store has a different purpose, and each varies in terms of capacity and duration
multi-store model of memory:
aprendete el diagram :)
MSM: sensory, STM and LTM memory
sensory register
-duration: 1/2 to 1/2 a second
-capcity: alll sensory experience (v.larger capacity)
-encoding: sense specific (e.g. different stores for each sense)
short-term memory:
-duration: 0-18 seconds
-capacity: 7+/-2 items
-encoding: mainly acoustic
long-term memory:
-duration: unlimited
-capacity: unlimited
-encoding: mainly semantic (but can be visual and acoustic)
evidence supporting a distinction between STM and LTM: KF
Shallice and Warrington (1970), The Case of KF:
- KF, a 28 year old man who sustained brain injuries after a motorcycle accident
-he had an impaired STM, working alongside a fully functioning LTM
-intact LTM -> he was able to learn new information and recall stored information
-reduced capacity STM -> he was only able to store a couple of bits or chunks of information rather than the normal 5-9 chunks
evidence supporting a distinction between STM and LTM: HM
Milner (1966), The Case of HM:
-HM, a young man who suffered from epilepsy
-he underwent brain surgery to alleviate his epilepsy, which involved removing parts of his temporal lobes, including the hippocampus
-this operation left him with severe memory problems -> he could only recall events in his early life and was unable to recall events for about 10 years before the surgery. He could also not learn or retain new information
-however, he repeatedly read the same magazine without realising he had read it before and he was unable to recognise the psychologists who has spent long periods of time with him
-this suggests HM had a normal STM, but his LTM was detective and that it was no longer possible for him to lay down new memories in it, or if he could, he was unable to retrieve them
evidence supporting a distinction between STM and LTM: Drechman and Sahakian
1979
-administered a group of participants with a drug that blocks the action of acetylcholine in the brain, then gave them various memory tasks that tested either STM or LTM
-performance was compared with a control group
-found the experimental group performed at normal levels on the STM, but significantly more poorly on the LTM task
-suggesting STM and LTM work as a separate stored, involving different neurotransmitters
limitations of the MSM: oversimplified
-human memory is extremely complex and it is highly unlikely that such a simple model could reflect this
-for example, the model doesn’t consider the different types of things we have to remember
-while it greatly emphasises the amount of information we can handle, it disregards the nature of the information
-everyday experience tells us that some things are easier to remember than others and this can simply be because we find it more interesting, relevant, funnier, etc.
limitations of the MSM: the role of rehearsal
-there is considerable evidence that simple repetition is one of the least effective ways of passing on information
-there is also a strong evidence that long term memories can be formed without any apparent rehearsal
-Brown and Kulik (1977): they have described this type of remembering “flashbulb memory” which is where the insignificant details surrounding highly emotional and shocking events are imprinted directly into LTM without any rehearsal
limitations of the MSM: laboratory studies
-much of the supporting evidence for this model comes from laboratory studies
-given how artificial these studies are, findings may not reflect how memory works in everyday life
-it is possible to interpret the results of such studies in different ways
-it is possible that different experimental techniques can yield different results
Independent groups design: explanation + ads and disads
-> is an experimental design whereby different participant are used for each experimental condition, the researcher exposes seperate sets of randomly allocated participants different
experimental
-typically, one of the two groups acts as a control group, this is because it doesn’t really experiment or receive the treatment whereas the other group is being tested in contrast to the first group
Advantages:
-simple and straightforward design
-less time consuming
-wide range of participants = more accurate findings
Disadvantages:
-differences in participants age, gender can alter results
-harder to control variables = less accurate findings
-altered data if a groups foes worse than expected
what is the working memory model?
-by the early 1970s it was becoming clear that traditional information processing models, suchas the MSM, could not account for some of the findings from memory research
-it was clear that the STM store was far more complex than existing theories could account for
-Baddeley and Hitch (1974) contested the idea that STM was a single and entirely seperate store
-they referred to the case of KF who, while only having a digit span of two, could transfer new information to his LTM, suggesting that though there had been some disruption to STM, other aspects of his STM must have continued to function-there must be several components of STM
the working memory model: actual model
-according to Baddeley and Hitch, working memory is a complex and flexible system comprised of several interacting components
-Central Executive
-Phonological loop- phonological store, articulatory control processes
-Visuo-spatial sketchpad- inner scribe, visual cache
-Episodic buffer
the central executive:
-> is the supervisory system of working memory, itr controls and manages attention, planning, task switching, but has limited capacity
-it can process information from any sensory system (e.g. sight, sound) and coordinates the activity of other components in working memory
-it uses ‘slave systems’ like:
-phonologival loop (for verbal information)
-visuo-spatial sketchpad (for visual/spatial information)
-episodic buffer (for integrating information)
-these free up space for complex, allowing us to do more than one thing at a time, such as listening and watching
-the central executive is the most flexible but hardest to study, since it is less well understood compared to its slaves systems
phonological loop:
-> often called the “inner voice”, temporarily holds verbal information in a speech-based form, it has two parts:
1. phonological store: passively stores sounds
2. articulatory loop: repeats words in your head (subvocal repetition) to keep them active
phonological loop: Baddeley et al. study
Baddeley et al. (1975) Study:
-aim: investigates how word length affects the phonologival loop’s capacity
-method: participants were shown lists of 5 words (either short, single-syllable words or longe, multi-syllabic words) and asked to recall all of them
-findings: short words were recalled better than long words
-conclusion: the phonological loop’s capacity is based on the time taken to say words, not the number of items (about 1.5 seconds) this is known as the word length effect
visuo-spatial sketchpad:
-> is reffered to as the “inner eye”, it temporarily holds visual and spatial information, it has two components:
1. visual cache: passively stores visual data
2. inner scribe: actively rehearses spatial information
-Klauer and Zhao (2004) Study
Brain Imaging Findings:
-the left brain is more active during visual tasks
-the right brain is ore active during spatial tasks (Todd and Marois, 2004)
visuo-spatial sketchpad: Klauer and Zhao Study
Klauer and Zhao (2004) Study:
-aim: tested whether visual and spatial components are distinct
-method: participants completed eother a visual task (remebering Chinese ideographs) or a spatial task (remembering locations of dots) while also doing interference tasks (visual or spatial)
-findings: spatial tasks were disrupted more by spatial interference than visual, visual tasks were disrupted more by visual interference than spatial
episodic buffer:
-> is a general storage system that integrates information from the visuo-spatial sketchpad, phonological loop, central executive and long-term memory
-it was added to the working memeory model by Baddeley in 2000, as the original model couldn’t explain how people remember coherent chunks of information, like prose, better than unrelated words
-combines information across different parts of working memory and from long-term memory
-studies show that people with intact central executive function but amnesia could immediately recall prose but forgot it shortly after. This suggests the e.b. temporarily stored information before it fades
-helps explain why memory for coherent information (e.g., sentences) is better than for random words, it allows information to be structured and processed using both working and long-term memory
Baddeley and Hitch study:
-aim: to test whether short-term memory (STM) has more than one component
-procedure: participants were given a six-digit number (e.g., 863492) to repeat out loud while also completing a reasoning task (e.g., judging sentences like “A follows B- AB” as true or false)
-hypothesis: if STM is limited to simple storage, doing two tasks at once should impair perfomance on the reasoning task
-findings: participants performed well on both tasks, although the reasoning task was slightly lower, errors were minimal
-conclusion: STM involves more than one component, as people can perform multiple tasks simultaneously if they use different parts of memory. Baddeley and Hitch saw STM as a “working memory” that actively processes information, rather than just storing it. They also viewed long-term memory (LTM) as a passive store accessed by STM when needed
-this study helped develop the Working Memory Model
evaluating the working memory model:
-the WMM has been extremely influential and most cognitive psychologists now use the term working ememory in preference to the term STM
-it is a much more plausible model because it explains STM in terms of temporary storage and active processing
-it also incorporates verbal rehearsal as just one optional process within the articulatory loop, instead of being the sole modality and means of transferring information to LTM
-it attempts to explain how memory functions, rather than simply describing the structure of memory
weaknesses of the working memory model:
-the central executive has not been precisley defined: for example, the term “process” is vague, and the central executive may be made up of several sub-components or even be part of a larger component itself in working memory
-this lack of a comprehensive explanation for each component of WMM draws doubts about the accurazy of its depiction of working memory
-Lieberman (1980) critisizes the working memory model as the visuospatial sketchpad (VSS) implies that all spatial information was first visual (they are linked)
-however, Lieberman points out that blind people have ecellent spatial awareness, although they have never had any visual information
-Lieberman argues that the VSS should be seperated into two different components: one visual information and one for spatial
strengths of the working memory model:
-Shallice and Warrington’s study of KF provides support for the WMM because their findings show that KF had very poor STM recall for auditory stimuli but increased STM recall for visual stimuli
-this suggests that the components of memory which process auditory and visual stimuli are seperate (thus, STM is not a single, unified system), as described in the WMM through the phonological loop and VSS
-Studies of dual-task perfomance, where each participant must undertake a visual and verbal task simultaneously, shows decreased perfomance for such tasks and so supports. the idea that the central executive has a very limited processing capacity (as predicted by the WMM) and that the slave systems are in competition with each other for these tasks and resources
more strengths of the working memory model:
-Baddeley et al. (1998) have presented evidence that the phonological loop, for exmaple, plays a key role in the development of reading, and that for children with dyslexia their phonological loop is not working properly
-while the phonological loop seems to be less crucial for fluent adult readers, is still has an important role in helping to comprehend complex text, it also helps in the learning of new vocabulary
-Turner and Engle (1989)
-Neuroscanning evidence, such as that provided by Braver et. al has demonstrated a positive correlation between an increasing cognitive load processed by the central executive (marked by increasing task difficulty) and increasing levels of activation in the prefrontal cortex
-this supports the idea that the central executive hs the role of allocating tasks to slave systems and has a limited processing capacity, as reflected by the increased brain activation levels, thus suggesting that the WMM is accurate in its mechanism of the central executive
Turner and Engle:
1989
-Turner and Engle devised a test to measure the capacity of working memory
-they asked participants to hold a list of words in memory while at the same time working out mental arithmetic problems
-the number of words correctly recalled in a subsequent test was called the ‘working memory span’
-this measure of working memory capcity has been shown in a number of studies to be linked to the ability to carry out various cognitive tasks, such as reading comprehension, reasoning, spatial navigation, spelling, and note taking (Engle et al. 1999)
The effects of leading questions on the accuracy of EWT:
-memories witnesses create at the time of an event appear to be quite fragile and subject to distortion by things that happen after the event
-consequently, serious errors in EWT can occur
-it’s been found that witnesses who encounter inaccurate information after an event can absorb this into their memory, thus distorting the actual memory of the event -> Loftus (1992) calls this “misinformation acceptance”
-research algo suggests that there is a tendency for the misinformation effect to become stronger as the time between the witnessed event and recall of it becomes greater
Loftus and Zanni:
-1975
-participants were shown as brief video of a car accident and then asked a series of questions
-half of the participants were asked -> had they seen “a” broken headlight
-half of the participants were asked -> had they seen “the” broken headlight
-there was no broken headlight in the film
-17% of those asked about “the” broken headlight reported seeing one
-7% asked about “a” broken headlight reported seeing one
-those in the “the” condition -> gave fewer uncertain responses, such as “I don’t know” -> suggests they had greater confidence in memories for events that never occurred