memory

• cognitive psychologists believe that human behaviour can best be explained if we first understand the mental processes that underlie behaviour

  • memory is the study of how people learn, structure, store and use information
• • compare the mind to a computer

  input -> processing -> output

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  storage

  the information is then stored after processing
• memory - broadly defined as the process by which we retain information about events that have happened in the past

  • it is used for remembering how to do things such as - ride a bike. the memory is also important for everyday tasks such as - talking to friends and family.
• short term memory - information that we process and recall straight away. the STM stores information we are currently aware of.

  • to take in new information to store we must process it from sensory input
• long term memory - continual storage which is largely outside of our awareness. information in the STM can be transferred to the LTM

  • LTM potentially has an unlimited capacity and can hold information for years until we want to retrieve it
• duration - how long the memory lasts
• capacity - how much can be stored
• coding - how the memory is transformed for storage
• capacity

  • LTM - infinite, loss of memory can happen through decay
  • STM - limited capacity, 5-9 units at one time
• factors that influence memory

  • age
  • chunking - breaking down information into memorable categories, it then becomes easier to remember
• Jacobs (1887) - capacity

  method - participants are presented with a long sequence of digits or letters that they had to report back in order

  results - students had an average span of 7.3 letters and 9.3 numbers
• evaluation of Jacobs capacity study (1887)

  • used 443 females from The North London School
  • conducted a long time ago - lacks temporal validity, no knowledge or technique to conduct a study
  • lacks mundane realism

  however,

  • large sample size so can be generalised
  • findings are supported by miller so good reliability
• Miller (1956) - capacity

  • published a famous article 'The magical number seven, plus or minus two' he reviewed existing research in the short term memory.
  • he believed that our STM stores 'chunks' of information rather than individual letters or numbers.
  • he found that people were able to break things down into manageable chunks - chunking
• evaluation of Miller capacity research (1956)

  • psychological support - Jacobs found that each student had an average of 7.3 letters and 9.3 numbers which supported Millers notion of 7 +/-2

  however,

  • Miller did not specify how large each 'chunk' is so we are unable to conclude the exact capacity of the STM
  • Miller's research did not take into account of other factors that affect capacity e.g. age
• duration

  • LTM - infinite
  • STM - 30 seconds
• Peterson + Peterson (1959) - duration STM

  method - shown a trigram, participants are given sets of 3 letters. they then are asked to count backwards from a 'said number' and then write down the trigram if it was remembered.

  results - participants had forgotten all trigrams after 18 seconds of counting backwards. counting backwards was used to distract the participants from the trigram

  conclusion - if too many pieces of information are stored in the short term memory, then displacement happens meaning the first piece of information stored in the STM is the first piece to be replaced
• evaluation of Peterson + Peterson STM duration study (1959)

  • lacks mundane realism
  • participants can guess the aim of the experiment

  however,

  • the experiment was done in a controlled environment so reduces extraneous variables
  • the experiment can be replicated due to the high control
• Bahrick (1975) - duration LTM

  method - 392 American graduates were asked to correctly match names to faces in their yearbook

  results - Bahrick found that 14 years after graduating 90% of the participants were able to correctly match the names and faces, and 47 years after graduation 60% of the participants were able to correctly match the names and faces.

  conclusion - people can remember certain types of information such as names and faces for a lifetime
• evaluations of Bahrick's LTM duration study (1975)

  • has high ecological validity (good relevance to life). reflect our memory for real life events.

  however,

  • 392 students all similar age so lack population validity
  • his research is unable to explain whether LTM becomes less accurate over time because of a limited duration or it simply gets worse with age. therefore psychologists are unable to determine whether our LTM has an unlimited duration (like the MSM suggests), which is affected by other factors, such as getting old. or whether our LTM has a limited duration.
• episodic memory - memory of an event (episode)
• semantic memory - meanings behind memories
• Baddeley coding study (1966)

  method - participants were shown a random sequence of words from one of four categories (acoustically similar, acoustically dissimilar, semantically similar, semantically dissimilar) and were asked to recall the words in order

  STM - asked to recall the words immediately

  LTM - asked to recall the words 20 minutes after and were occupied with a different task

  results - acoustically similar words were harder to recall than acoustically dissimilar words. Semantically similar words were harder to recall than semantically dissimilar words.
• Baddeley coding study (1966)

  conclusions -found that we mixed up words that sounded similar (acoustically) when using our STM and mixed up words that have similar meanings (semantically) when using our LTM

  so the STM is coded acoustically and the LTM is coded semantically
• evaluation of Baddeley's coding study

  • small sample size, 72 people, so lacks population validity
  • lab study so lacks ecological validity
  • lacks mundane realism as the procedure used is not similar to real life

  however,

  • lab study, so can be easily replicated and presents high reliability
  • beneficial for real life events e.g. students revising
• encoding - the way information is stored/processed into the memory
• multi store model - Atkinson and Shiffrin (1968)

  A) sensory register

  B) decay

  C) short term memory

  D) forgetting

  E) attention

  F) maintenance rehearsal

  G) rehearsal

  H) retrieval

  I) long term memory

  
• multi store model - sensory register

  • stimulus enters via the sensory register
  • information stays in sensory register for 0.5 seconds before it decays or goes into the short term memory
  • little of what goes into the sensory register passes into the memory, but it will pass through if you pay attention
  • very large capacity

  Atkinson and Shiffrin proposed that we mainly use iconic memory (visual) or echoic memory (acoustically/sounds)
• multi store model - short term memory

  • small duration, around 30 seconds
  • 7 +/-2 items (capacity)
  • maintenance rehearsal, repeat the material in the STM over and over it will pass into the LTM
• multi store model - long term memory

  • information that has been rehearsed for a long period of time
  • coded semantically
  • limitless capacity and duration
  • although information is stored in the LTM, when we want to recall the information we must transfer it back to the STM
• evaluations of multi store model

  • support from studies showing that the STM and LTM are different e.g. Baddeley (1966)
  • lab study, so high control meaning valid results

  however,

  • the studies used to support the MSM model are not every day tasks so therefore lacks mundane realism
  • more than one STM store e.g. case study of HM
  • lab study so therefore lacks ecological validity
• Glanzer and Cunitz (1966) - primary and recency effect primary effect - tendency for people to remember the first 5 or so words from the beginning of the list recency effect - tendency for people to remember the last 5 or so words from the end of the list.

  this links to the MSM because;

  • the primary effect, the first few words are being rehearsed so they made it through the STM and transferred to the LTM
  • the recency effect, the last few words are still in the STM as they are fresh and can be recalled
• the working memory model - Baddeley and Hitch (1974)

  • believed the Multi Store Model underestimated the complexity of the STM
  • in the Working Memory Model there are a variety of operations that can take place in the STM (auditory, visual)
• The Working Memory Model - central executive

  • acts as the boss of The Working Memory Model
  • directs attention
  • responsibilities are to monitor and coordinate the other systems
  • information arrives via the senses
  • coding is not limited to one form
  • has a limited capacity
• The Working Memory Model - phonological loop

  • codes acoustically
  • 2 separate stores (phonological store and articulatory control system)
  • phonological store - spoken words enter directly for 1-2 seconds before it fades or goes into the STM
  • articulatory control system - holds words that are heard and silently repeats them, acts as an inner voice
• The Working Memory Model - visuospatial sketchpad

  • limited capacity, 3-4 items
  • visuo (what we see), spatial (our relationship between things)
• The Working Memory Model - episodic buffer

  • temporary storage system that combines all information from all stores before its coded into the LTM
  • limited capacity, 4 items
• evaluation of WMM

  • case study of KF, motorbike accident. after he had poor auditory information recall but could process visual information normally. this suggested his phonological loop was damaged but his visuospatial sketchpad wasn't
  • 2 tasks from the same subsystem are harder to complete than 2 tasks from separate subsystems

  however,

  • unclear if KF had other cognitive impairments
  • lack of evidence around the central executive, Baddeley said it was the most important but the least understood
  • studies done in labs and procedures were not similar to real life (lacks mundane realism)
• types of LTM (Tulving - 1985)

  • episodic - store of personal events, retains memories of when events occurred and the people, objects and places involved. Memories from this store have to be retrieved consciously and with effort.
  • procedural - responsible for knowing how to do things. it is unconscious and automatic. for example riding a bike.
  • semantic - meanings behind things, involves remembering general knowledge, concepts and facts that are not tied to a specific personal experience.
• interference - information is forgotten because 2 or more pieces of information interfere with one another. It means the memories are available but not accessible due to other information

  • retroactive - when a new memory interferes with an old memory (McGeoch and McDonald (1931))
  • proactive - an old memory interferes with a new memory (Keppel and Underwood (1962))
• McGeoch & McDonald (1931)

  aim - to test retroactive interference

  procedure - participants learnt a list of 10 words until recall was 100% accurate. the participants then learnt a second list of 10 words from 1 of 6 groups (synonyms, antonyms, unrelated words, nonsense syllables, 3 digit numbers and no new list the participants rested) after learning the second list the participants were asked to recall the first list of 10 words.

  findings - Recall of the first list was worse in every condition

  • this supports interference because it showed that new words affected the old words.