memory

• STM

  • for events in the present or immediate past
  • small amounts of information for a short period of time
• LTM


  • for events in more distant past
  • unlimited space for information for long periods of time even for life
• Capacity 


  How much data can be held in a memory store
• Duration 


  How long the data can be held in a memory store. Duration of STM is 18-30 seconds
• Coding 


  depending on the memory store information is stored in different forms (visual, acoustic or semantic)

  LTM coding is semantic

  STM coding is acoustic
• Baddeley- coding research 


  Group 1: acoustically similar

  Group 2: acoustically dissimilar

  Group 3: semantically similar

  Group 4: semantically dissimilar

  • STM (immediate recall) – participants did worse with acoustically similar words =coded acoustically (distracted by acoustic similarities and muddled up)

  • LTM (20 minute time interval) – participants did worse with the semantically similar words = coded semantically (pays no attention to how words sound)
• Capacity (Jacobs)


  • Participants are given 4 digits and then asked to recall these in the correct order out loud
  • This goes up by one digit until participants cannot recall the correct order anymore
  • This determines the individuals digit span
  • Jacobs found the mean span for digits across all participants was 9.3 items and for letter 7.
• Miller (capacity) 


  George Miller (1956): average items held in STM is 7 +/- 2 (this is known as the magic number)

  Capacity of LTM: infinite capacity
• What is chunking

  taking individual pieces of information and grouping them into larger units
• Capacity (Peterson and Peterson)

  • 24 undergraduate students.

  • 8 trials.

  • given a trigram (YGC) and a 3 digit number to remember

  • After showing the trigram students were asked to count backwards from the 3 digit to prevent mental rehearsal of the trigram.

  • On each trial they were asked to stop after a different amount of time (3, 6, 9, 12 second etc) – known this retention interval

  Percentage of accurate recall decreased with retention Interval Suggests that STM has a short

  duration unless it is repeated

  over and over again.

  • Duration of STM is between

  18 and 30 seconds.
• Duration- Bahrick et 


  392 people aged 17-74

  P’s high school yearbooks obtained

  2 ways recall was tested:

  • Photo recognition test: 50 photos,

  • Free recall: PPTs asked to list all the names they could remember of those in their graduating class.

  Findings

  Photo recognition:

  • Within 15 years of graduation: 90% accurate

  • After 48 years: 70% accurate

  Free recall:

  • After 15 years: 60% accurate

  • After 48 years: 30% accurate

  • This suggests that LTM can last a long time
• STM and LTM summary


  Summary notes

  
• The multi store memory model

  MSM

  
• The developed the multi store memory model

  Atkinson and Shiffrin
• Sensory register 


  Sensory register

  
• Case study of HM for MSM

  • suffered from epileptic seizures

  • hippocampus damaged at operating table

  • The procedure left him

  with amnesia

  • Anterograde amnesia: Inability to form any new memories after the

  operation (despite this, he did learn new skills, although he had no

  memory of being able to learn them)

  • Retrograde amnesia: lost the ability to retrieve memories from 19

  months to 11 years prior to the operation

  • The study of HM supports the model because it shows that the long

  term and short term memories are two distinct stores
• AO1 paragraoh: MSM


  MSM

  
• Case study of KF: what did it find (evaluation of MSM)

  There is more than one type of STM
• Case study of KF

  • Evidence from people suffering from amnesia shows that this cannot be true

  • For example, KF suffered brain damage from a motorcycle accident that damaged his STM.

  • KF was asked to recall a set of digits under two conditions.

  • Digits were read out aloud to KF

  • KF read the digits himself

  How did KF perform on these tasks?

  • KF’s STM for digits was very poor when they read them out loud to him. But his recall was much better when he was able to read the digits to himself.

  • This shows that there could be another short-term store for non-verbal sounds (Such as noises)
• How is the case study if KF critical of MSM

  The unitary STM is a limitation of the MSM because research shows that there must be one short-term store to process visual info
• What else is a criticism of the MSM? There is more than one type of ___

  Rehearsal
• What did Craik and Watkins find out about rehearsal

  • The more you rehearse the likely it gets transferred to the LTM

  Who found that this prediction was wrong?

  • Craik and Watkins (1973) found that this prediction is wrong.

  • What really matters about rehearsal is the type.

  What are the two types of rehearsal?

  • 1) Maintenance rehearsal: Described in the MSM – does not transfer information into LTM, just maintains it in STM

  • 2) Elaborative rehearsal: needed for long term storage. Occurs when you link the information to your existing knowledge, or you think about what it means
• What is episodic memory

  • ability to remember person experiences from our lives
  • time stamped
  • requires conscious effort to recall
  • can be made up of many elements e.g people, objects, places
  • strength memory depends on the intensity of emotion at time of coding and that’s why traumatic memories are more memorable
• what is procedural memory

  -memory of motor skills

  -can be recalled without conscious awareness (implicit)

  -actions done without needing to recall how to do them and are often difficult to explain
• Who conducted the study on context

  dependent forgetting?

  Godden and Baddeley
• What is context and state dependent forgetting?


  Context=external environmental cues

  State= internal cues
• what was the finding for state dependent forgetting?

  In conditions where there was a mismatch between internal state at learning and recall, performance on mem test significantly low
• WHO PROPOSED THAT THE MSM VIEW OF LTM WAS TOO SIMPLISTIC AND

  INFLEXIBLE?

  Tulving
• Tulving said that the MSM view of the LTM is too simplistic. What studies support his view?

  HM and Clive Wearing
• Clive Wearing supports Tulving's view that the MSM's depiction of the LTM is too simplistic and inflexible. How?

  P- C.W can be used as evidence for Tulving's theory of multiple different types of memory.

  E- after his brain damage C.W was not able to remember specific details about his life such as the faces of his children but was able to play the piano and understand the meaning of words.

  E- this shows that there are multiple types of LTM because he damaged his episodic memory but his procedural and semantic memory was intact.

  L- this increases the validity for Tulving's theory.
• Another strength of Tulving's theory of different types of LTM (episodic, semantic, procedural) is that there is neuroimaging evidence. (procedure and results)

  Procedure- got p's to perform various memory tasks while their brains were scanned with a PET scanner.

  Results- found that episodic and semantic memories were recalled from the prefrontal cortex (this area is divided into 2 and each hemisphere is responsible for one of them)

  Conclusion- physical reality of different LTM stores
• working memory model

  this is how it looks

  
• What did Baddeley and Hitch say?

  • the short term memory in the MSM is too simplistic
  • STM is not a unitary store
  • model consists of 4 main components which differ in capacity and coding
• according to the WMM the STM has different stores for visual and acoustic information. this means that...


  dual performance in one area is harder (e.g two visual tasks) but doing two tasks if one is visual and one is acoustic there is no interference.
• what does the central executive do

  • most important part
  • controls slave systems and coordinates actions (e.g makes decisions)
  • limited capacity
  • evidence suggests it is located in the prefrontal cortex
• what does the phonological loop do, what information does it store and how and what capacity does it have

  • slave system
  • auditory information + acoustic coding
  • limited capacity
• what does the phonological loop consist of

  the inner ear (phonological store) and the inner voice (articulatory control process)
• what does the inner ear (phonological store) do


  stores words you recently heard
• what does the inner voice (articulatory control process) do and what is its capacity?

  • allows maintenance rehearsal
  • capacity: 2 seconds worth of what you can say
• what is the visuospatial sketchpad, what does it do, capacity and coding?

  • inner eye
  • stores and manipulates visual information (what you see) and spatial information (where things are in relation to eachother)
  • coded visually
  • capacity of 3-4 objects