Memory

• Coding

  When info gets into the memory system it is stored in different formats
• Baddeley's study


  1. Gave different lists of words to 4 groups of participants to remember

  2. Group 1 - acoustically similar words

  3. Group 2 - acoustically dissimilar words

  4. Group 3 - semantically similar words

  5. Group 4 - semantically dissimilar words
• When asked to recall after hearing the words (to test STM)

  They did worse with acoustically similar words = information is coded acoustically in STM
• When asked to recall words after 20 mins (to test LTM)

  They did worse with semantically similar words = information is coded semantically in LTM
• Capacity

  Amount of info that can be held in a memory store
• Jacobs' study


  1. Gave participants 4 digits and asked them to recall in order, then increased by 1 digit each time until they couldn't recall correctly

  2. Determined the mean digit span to be 9.3 items, and the mean span for letters was 7.3
• Miller


  Capacity of the STM is 7+/-2, individuals recall by chunking which involves making info more meaningful by organising it in line with existing knowledge in the LTM
• Duration (STM)


  • Peterson and Peterson tested 24 undergraduate students using consonant trigrams
  • Found: 90% of trigrams recalled after 3 seconds, fewer then 10% after 18 seconds = STM has a short duration if we don't rehearse thus decay causes forgetting in STM
• Duration (LTM)


  • Bahrick studied 329 American participants aged 17-74
  • Photo recognition: 90% accurate recall after 15 years, 70% after 48 years
  • Free recall: 60% accurate after 15 years, 30% after 48 years = LTM has a long duration
• Multi-Store Model of Memory

  Proposed by Atkinson & Shiffrin that memory consisted of 3 stores: sensory register, STM and LTM. Information passes from one to the other in a linear way
• Sensory register


  • Capacity: high - all sensory experience
  • Encoding: iconic coded visually, echoic coded acoustically
  • Duration: 250 milli seconds
  • For info to pass further you have to pay attention to it
• STM


  • Capacity: 7+/-2 items
  • Encoding: mainly acoustic
  • Duration: 0-18 seconds unless rehearsed
• LTM


  • Capacity: unlimited
  • Encoding: mainly semantic (can be visual/acoustic)
  • Duration: unlimited
  • When we want to recall the memory has to be transferred back to STM – retrieval. None recalled directly from LTM
• Episodic memory


  • Refers to the ability to recall events from our lives, like a diary
  • They are complex: (1) 'time-stamped', (2) memory of a single episode will also include memories of the people involved, objects, behaviours etc. (3) a conscious effort has to be made to recall these memories
• Semantic memory


  • Contains our knowledge of the world, it is less personal and is usually facts we all share, e.g. how to apply to uni
  • These memories are not 'time-stamped'
  • It is a big list of things we know of and is constantly being added to
• Procedural memory


  • Our memory of actions/skills/basically how we do things, e.g. how to ride a bike
  • They are able to be recalled without conscious effort
• Central executive (Working Memory Model)


  • Monitors incoming data, decides how attention is directed, makes decisions and allocates slave systems to tasks
  • Limited capacity - can't attend to many things at once
• Phonological loop


  • Deals with auditory information, coding is acoustic and preserves word order
  • Phonological store: Limited capacity - holds words you hear for 1-2 seconds
  • Articulatory control process: allows maintenance rehearsal so inner voice repeats the words heard to keep them in the working memory. Capacity: 2 seconds worth of what you can say
• Visuo-spatial sketchpad


  • Holds visual and spatial info for a short time, coded visually includes:
  • Visual cache: passive temporary visual store
  • The inner scribe: active rehearsal mechanism when records the arrangement of objects
• Episodic buffer


  More general store, Integrates information from all other areas, small storage capacity
• Interference


  • Forgetting from LTM because one memory blocks another, causing one or both memories to be distorted/forgotten
  • Proactive interference: when an older memory interferes with the recall of a newer one
  • Retroactive interference: when a newer memory interferes with the recall of an older one
• Similarity


  McGeoch et al said interference is WORSE when the memories are similar
• Retrieval failure


  Forgetting because the associated cues encoded at the same time as the memory are not available at the time of recall