Memory topic

• Multi-store model of memory

  Proposed by Atkinson and Shiffrin, memory consists of three stores: sensory register, short-term memory (STM), and long-term memory (LTM). Information passes from store to store in a linear way.
• Sensory memory


  • Information you get from your senses, eyes, and ears. When attention is paid, it is converted to short-term memory.
• Short-term memory (STM)


  • Information from sensory memory is transferred to STM only if it is rehearsed (repeated).
• Maintenance rehearsal


  • Repetition that keeps information in STM, but eventually creates an LTM.
• Forgetting from STM


  • If maintenance rehearsal (repetition) does not occur, information is forgotten and lost from STM through displacement or decay.
• Encoding


  • The way information is changed so it can be stored in memory. Three main ways: visual (picture), acoustic (sound), and semantic (meaning).
• Capacity


  • How much information can be stored.
• Duration


  • The period of time information can last in memory stores.
• Characteristics of memory stores

  • Sensory register: Duration: ¼ to ½ second, Capacity: all sensory experience, Encoding: sense specific
  • 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)
• Rehearsal


  Helps transfer information into LTM, but is not essential
• We can recall information we did not rehearse (e.g., swimming) yet unable to recall information we have rehearsed (e.g., reading your notes while revising)
• The role of rehearsal as a means of transferring from STM to LTM is much less important than Atkinson and Shiffrin (1968) claimed
• Procedural memory


  Part of implicit long-term memory responsible for knowing how to do things, i.e., memory of motor skills. It is unconscious and automatic.
• Semantic memory


  Part of long-term memory responsible for storing information about the world, including knowledge about the meaning of words and general knowledge. It involves conscious thought and is declarative.
• Episodic memory


  Part of long-term memory responsible for storing information about events (episodes) we have experienced in our lives. It involves conscious thought and is declarative.
• Semanti knowledge

  Knowing that, e.g. London is the capital of England. Involves conscious effort to recall information.
• Procedural knowledge


  Knowing how to do things, e.g. riding a bike. It is unconscious and automatic.
• Working memory model


  • Proposed by Baddeley and Hitch, replaced the idea of a unitary STM. Involves active processing and short-term storage of information. Key features: central executive, phonological loop, visuospatial sketchpad, episodic buffer.
• Central executive


  Supervisory function, acts as a filter, determines which information is attended to. Can process information in all sensory forms, direct information to other slave systems, and collects responses.
• Phonological loop


  Temporary storage system for holding auditory information in a speech-based form. Includes the phonological store (inner ear) and the articulatory process (inner voice).
• Visuospatial sketchpad (VSS)


  Temporary memory system for holding visual and spatial information. Includes the visual cache (stores visual data) and the inner scribe (records arrangement of objects and rehearses/transfers information).
• Episodic buffer


  Acts as a "backup" (temporary) store for information that communicates with both long-term memory and the slave system components of working memory.
• Bryan's driving experience


  He can hold conversations or listen to music with little difficulty while driving
• Bryan is able to divide the different components of his short-term memory because he is experienced at driving and doesn't need to devote all his attention to it
• Visuospatial sketchpad


  Slave system that processes visual and spatial information in working memory
• Episodic buffer


  Temporary store for information that communicates with both long-term memory and the slave system components of working memory
• One function of the episodic buffer

  Recalls material from LTM and integrates it into STM when working memory requires it
• Dual-task studies support the working memory model
• It is easier to do two tasks at the same time if they use different processing systems (verbal and visual) than if they use the same slave system
• The KF case study supports the working memory model
• KF's impairment was mainly for verbal information - his memory for visual information was largely unaffected
• Evidence from brain-damaged patients may not be reliable because it concerns unique cases with patients who have had traumatic experiences
• The working memory model does not explain the link between working memory and long-term memory
• Baddeley and Hitch experiment

  1. Participants performed a digit span task and a verbal reasoning task simultaneously

  2. As the number of digits increased, participants took longer to answer the reasoning questions, but not much longer

  3. Participants didn't make any more errors in the verbal reasoning tasks as the number of digits increased
• The verbal reasoning task made use of the central executive, and the digit span task made use of the phonological loop
• Interference


  An explanation for forgetting from long-term memory - two sets of information become confused
• Proactive interference


  Old learning prevents the recall of more recent information
• Retroactive interference


  New learning prevents the recall of previously learned information
• Semantic memory is more resistant to interference than other types of memory
• Postman (1960) experiment


  1. Participants learned a list of paired words

  2. Experimental group also learned a second list with different second paired words

  3. Control group did not learn the second list

  4. Experimental group recalled the first list less accurately, suggesting retroactive interference