MEMORY

• Memory


  The retention of what we learn and what we experience
• Memory processes identified by psychologists

  • Encoding
  • Storage
  • Retrieval
• Multi-Store Model of Memory

  A good example of an information processing theory, seeing cognitive processes in a sequence of stages and comparing them with the operations of a computer
• Stores in memory


  • Sensory memory
  • Short-term memory
  • Long-term memory
• Stores in memory


  • They differ in terms of encoding, duration and capacity
• Rehearsal


  The main process within the multi-store model, it involves repeating information in your mind. It was initially described by Atkinson and Shiffrin as maintenance rehearsal but Shiffrin later suggested that rehearsal could be elaborative
• Sensory Register (SR)


  Information in this store is attended to and so receives further processing in the short-term store. Any information in the sensory memory, which is not selected in this way, simply decays rapidly
• Sensory Register


  • It is not under cognitive control, it is an automatic response to the reception of sensory information by the sense organs and is the first storage system within the MSM
  • Material in SR lasts only very briefly-the duration is less than half a second
  • The SR have a high capacity-over one hundred million cells in one eye, each storing data
  • Information is coded depending on the sense that has picked it up eg. visual, auditory or tactile
• Sperling (1960) investigated the sensory register using very brief displays
• Coding in Short-Term Memory (STM)

  Information can be coded semantically (in terms of meaning), acoustically (in terms of sound) or visually (in terms of images). The main encoding system used in STM is acoustic
• Research (Baddeley 1995) showed that participants performed worse at recalling acoustically similar words compared to semantically similar or dissimilar words
• Capacity of Short-Term Memory

  Short-term memory has a very limited capacity of not more than 7 or so items and information in the store is in a fragile state. This can be increased by chunking, which involves grouping separate items into chunks, with each chunk then constituting a single item
• Miller (1956) found the average digit span was 7 plus or minus 2
• Duration of Short-Term Memory

  Rehearsal is the main process in this short-term store and information can be kept in the short term store for more than 30 seconds by verbally rehearsing it in the rehearsal loop
• Brown & Peterson (1958) found that only 10% of triagrams were recalled after 18 seconds using the Brown-Peterson technique
• Capacity of Long-Term Memory

  Long-term memory has an unlimited capacity. Forgetting often occurs because of confusion among similar long-term memories rather than the disappearance of the trace from memory
• Atkinson (1975) estimated the number of possible neuronal connections in the human brain is 1 followed by 10.5 km of noughts, suggesting the capacity of LTM is limitless
• Coding in Long-Term Memory

  Coding in LTM is mainly semantic and the deeper the level of processing that occurs when information is being experienced, the stronger the memory trace will be
• Duration of Long-Term Memory

  Memories can last a lifetime, they will last longer if well coded when inputted. Memories based on skills tend to last longer and don't necessarily have to be continually rehearsed
• Bahrick (1975) found that recall of high school yearbook photos declined from 90% accurate within 15 years to 70% after 48 years, while free recall declined from 60% to 30% over the same period
• Murdock's Primacy and Recency Effect (1962) supports the existence of separate short-term and long-term stores
• The case of HM supports the multi-store model by showing long-term memory impairment but intact short-term memory after brain damage
• The case of KF criticises the multi-store model by showing intact visual short-term memory but impaired verbal short-term memory after brain damage, suggesting short-term memory is not a unitary store