memory

• what is the duration of short term memory

  18-30 seconds
• research into duration of stm

  Peterson and Peterson (1959) showed pps a trigram. They then had to recall the trigram after counting backwards in 3s from 300. The length of time varied from 18-30 seconds. The longer the delay the less trigrams recalled
• what is the capacity of short term memory

  7 +/- 2
• research into capacity of stm

  Miller (1956) showed pps a list of 4 letter which they recalled. If successful the amount of letters would increase until unable to recall
• what is the coding of short term memory

  acoustic
• research into coding of stm

  Baddeley et al (1966) showed 2 groups of pps different word lists and asked to recall immediately. In first condition words were acoustically similar therefore recall was lower as stm coddes acoustically so recall caused acoustic confusion
• what is the duration of long term memory

  lifetime
• research into duration of ltm

  Bahrick et al (1975) put pps into 2 categories. First recalled high school class members from free recall. The second category matches names and pictures of classmates. Recall was best. when students were younger and had picture cues
• what is the capacity of long term memory

  unlimited
• what is the coding of the long term memory

  semantic
• research into coding of ltm

  Baddeley et al (1966) showed 2 groups of pps different word lists semantically similar and not. The performance was compared showing that random words were recalled better due to others experiencing sematic confusion
• strength of research into duration of ltm

  -A strength of Bahrick's researxh is that it has high external validity.

  -Bahrick used photos that would be semantically coded as they had meaning to individual.

  -Real life memories were studied rather than fake stimuli. -This is a strength as it means it is more applicable to how memory works and therefore more generalisable
• weakness of research into capacity of stm

  -One weakness of Miller's research is that it was conducted a long time ago.

  -Early psychology experiments were criticised as they were not conducted in a controlled manner.

  -For example some participants may have been distracted during testing.

  -This is a weakness as it means the resukts obtained may not actually be a true reflection of the capacity of stm therefore the study lacks internal validity
• weakness of research into duration of stm

  -One limitation of Peterson and Peterson is that it lacks external validity

  -As they use trigrams as stimuli which lacks meaning to pps

  -Trigrams are 3 letter nonsense words that are unusual to pps stimulating unusual behaviour

  -This means that research has kimited ecological validity making it difficult to generalise
• how does information travel through the multi-store model

  environmental stimuli

  sensory register

  short term memory

  maintenance rehearsal

  long term memory

  
• features of sensory register

  duration - 0.5 seconds

  capacity -unlimited

  coding- uncoded/by sense
• strength for multi store model (memory research)

  -There are multiple different studies showing the existence of the seperate stores and how different they are.

  -For example Bahrick showed the duration of ltm and how infomation is retreived back to stm

  -And research by Baddeley showed the impirtance of coding stm + ltm differently

  -This is a strength of model as the abundance of empirical evidence adds validity to the theory
• strength for multi store model (primary/recency effect)

  -The primary effect can add validity to MSM

  -When remembering lists of words we often forget the words in the middle

  -This is because the first set is rehearsed into the ltm and the last set is more recent so fill up the stm capacity.

  -This clearly shows how information flows through the MSM but also supports the idea that STM and LTM are different in terms of coding and capacity as there is limited space in stm capcity therefore the middle set is displaced proving differences in MSM stores
• weakness of multi store model (bypass rehearsal)

  -Morris et al (1977) challenges the importance placed on rehearsal by the MSM

  -Their study showed that information can bypass yhe LTM when information is of interest to pps

  -This is because the information is more meaningful so codes semantically

  -This means that information can bypass the LTM store limiting the need for rehersal time contradicting the model decreasing the validity of explaination
• weakness of multi store model (complexity of stores)

  -There is evidence to suggest that the accounts of STM + LTM within the MSM are too basic.

  -For example the case study of KF showed a motorcycle accident KF could recall visual information but struggled to recall verbal information.

  -This indicates that there is potentially more than one store within the STM rather than one store that does everything

  -Suggesting the MSM idea of a unitary STM is flawed and that there are multiple stores in which STM is stored suggesting the MSM is a simplifed version of STM
• What is episodic memory

  long term memory store for personal events including memories of where event occured,people and places.
• Types of LTM

  episodic

  semantic

  procedural
• features of episodic memory

  memories are time and location stamped.

  Consciously recalled and declarative

  located in hippocampus
• what is semantic memory

  long term memory store for knowledge of the world including facts and meanings
• features of semantic memory

  memories are not time stamped and declarative

  located in the temporal lobe
• what is procedural memory

  A long-term memory store for our knowledge of how to do things. This includes our memories of learned skills.
• features of procedural memory

  not time stamped

  not consciously recalled or declarative

  located in cerebellum
• strength of types of ltm (memory loss)

  -The case study of Clive Wearing adds support to separate long term memory stores

  -Although he experienced amnesia due to his accident he lost episodic but not procedural

  -It is likely that his hippocampus was damaged but his cerebellum remained intact

  -This shows that there are separate stores located in different places adding validity to the theory
• strength of types of ltm (neuroimaging)

  -Support for the existence of seperate LTM stores comes from brain scans

  -For example Tuving et al (1994) used PET scans while pps were carrying out different tasks to see which part of the brain was active.

  -He found that episodic and semantic were recalled from the prefrontal cortex (hippocampus and temporal lobe) wheras procedual memories where carried out in cerebellum.

  -This shows that there are different LTM stores as they are located in seperate parts of brain. Supporting the existence as it is a empirical study
• weakness of type of ltm (declarative and non declarative)

  -Cohen and Squire (1980) suggested that there were 2 stores

  -He termed these non-declarative and declarative.

  -Further support comes from Clive Wearing as his declarative was damaged but non-declarative wasn't.

  -This shows that there is a lack of understanding and further research should be done into whether episodic+semantic are seperate
• weakness of type of ltm (4 stores?)

  - we don't have a comprehensive understanding of different LTM stores comes from the suggestion of 4 stores

  -This 4th type of LTM is responsible for priming

  -Priming is the idea of association where exposure to one stimuli influences a response to another

  -This idea is not accounted for in the other 3 stores suggesting more research should be done
• what are the 4 features of the working memory model

  central executive

  phonological loop

  visuo-spatial sketchpad

  episodic memory

  
• features of the central executive

  -has overall control and

  limited capacity

  -can process infomation from any sensory modality

  delagates tasks to slave componenets

  -co-ordinates when more than 1 processing task needs to take place

  -involved in complex decision making
• features of phonological loop

  -deals with auditory info

  -made up of 2 stores

  -phonological store that is responsible for speech perception

  -articulatory process responsible for speech production

  -capacity 2 secs codes acoustically
• features of visuo-spatial sketchpad

  -stores infomation by organsiing it in a visual way

  -made up of 2 elements

  -inner scribe responsible for relationship between things

  -visual cache responsible for what things look like (form and colour)

  -codes visually in 3-4 object capacity
• features of episodic buffer

  -added by Baddley in 2000

  -coordinates and manipulates information from all other stores as well as long term memory

  -capacity of 4 chunks
• strength of working memory model (KF)

  -The case study of KF supports the working memory model

  -KF's phonological loop was damaged

  -his visuospatial sketchpad was fine as he could remember visual information

  -Meaning the stores are seperate as shown in WMM
• strength of working memory model (Robbins)


  -Support for this model comes from Robbins and his research using a game of chess

  -He found during a chess match players performed better with a secondary task that involved that phonological loop

  -This is because the games of chess uses up the central executive and visuospatial sketchpad so they couldn't be used for other tasks

  -This shows that multi tasking is only possible between two different components of WMM
• weakness of working memory model (Role of CE)

  -A weakness of WMM is the little knowledge into the central executive

  -This is the most important component yet there is limited evidence supporting it

  -This could be because the central execuative is difficult to falsify as it is difficult to know if the CE carries out the task or a slave component

  -This means it is difficult to determine whether the CE exists limiting the validity of the working memory model
• weakness of working memory model (EVR)


  -The case study of EVR involved a man who developed a cerebral tumour that was removed.

  -His functioning was affected in different ways e.g he lost the abiity to plan and organise his own life however he wasn't intellectually affected

  -This suggests there is a lack of understanding into the functions of the CE as not all central executive functions were affected