memory

• Memory


  The process by which we retain information about events that have happened in the past
• Coding


  • The format in which information is stored in the various memory stores
• Capacity


  • The amount of information that can be held in a memory store
• Duration


  • The length of time information can be held in memory
• Encoding


  The way information is changed so that it can be stored in memory
• Coding in short-term memory

  • Acoustic (by the way it sounds)
• Coding in long-term memory

  • Semantic (by what it means)
• Baddeley (1966) gave different lists of words to four groups of participants to remember. The mistakes made show the encoding in that part of memory.
• Short-term memory (STM)


  The limited capacity memory store. Coding is mainly acoustic, capacity is between 5 and 9 items on average, duration is between about 18 and 30 seconds.
• Long-term memory (LTM)


  The permanent memory store. Coding is mainly semantic, it has unlimited capacity and can store memories for up to a lifetime.
• Jacobs (1887) - Digit span

  • The average span was 9.3 for numbers and 7.3 for letters. Eight year olds could recall an average of seven digits, whereas by the age of 19 recall had increased to nine digits.
• Miller (1956) - Chunking


  • People can recall 5 words as well as they can recall 5 letters. This demonstrated the idea of chunking, grouping sets of things together into units or chunks.
• Wagenaar (1986) - LTM capacity

  • He found he had excellent recall, with no events being completely forgotten. This suggests that the capacity of LTM is very large.
• Peterson and Peterson (1959) tested 24 students who each took part in 8 trials. As time increased, participants found it harder to remember the trigrams, suggesting that the STM may have a very short duration unless we repeat something over and over again (verbal rehearsal).
• Bahrick et al (1975) - VLTM


  • Photo recognition was 90% accurate after 15 years and 70% accurate after 48 years. Free recall was 60% accurate after 15 years and 30% accurate after 48 years.
• Multi-store model (MSM)


  A representation of how memory works in terms of three stores called a sensory register, short-term memory (STM) and long-term memory (LTM). It also describes how information is transferred from one store to another, how it is remembered and how it is forgotten.
• Sensory register


  • The memory stores for each of our five senses, such as vision (iconic store) and hearing (echoic store). Coding in the iconic sensory register is visual and in the echoic sensory register it is acoustic. The capacity of sensory registers is huge (millions of receptors) and information lasts a very short time (less than half a second)
• Short-term memory (STM)


  • The memory store for events in the present or immediate past. STM is known as a limited capacity store, because it can only contain a certain number of 'things' before forgetting takes place. The capacity of STM is about 7 items (plus or minus 2). Information is coded acoustically and lasts about 30 seconds unless it is rehearsed.
• Long-term memory (LTM)


  • The potentially permanent memory store for information that has been rehearsed for a prolonged time. Capacity is unlimited (as suggested by Bahrick's study) and LTM's tend to be coded semantically.
• Cognitive processes in the MSM

  1. Attention - Focusing on stimuli to pass information from sensory register

  2. Maintenance rehearsal - Repeating an item over and over again to pass information from STM to LTM

  3. Recoding - May be needed between one store and the next

  4. Retrieval - Accessing and recovering stored information

  5. Forgetting - Inability to recall or recognise something previously learned (decay, displacement, retrieval failure, interference)
• The Multi-Store Model of Memory was proposed by Atkinson & Shiffrin (1968)
• The Multi-Store Model is the most well-known early model of memory processes
• The Multi-Store Model now appears simplistic, but it was a necessary first step in the scientific testing of memory
• The Multi-Store Model is based on the features of STM and LTM as well as a third store, the sensory register
• The Multi-Store Model identifies that there are cognitive processes that explain how information is transferred from one store to another
• Multi-Store Model


  A model of memory that states our memory consists of three separate stores: sensory register, short-term memory, and long-term memory
• Working Memory Model (WMM)

  An alternative explanation of short-term memory proposed by Baddeley and Hitch, which suggests short-term memory is processed by three different 'slave systems' coordinated by a central executive
• Working Memory Model


  • Instead of all information going into one single store (like in the Multi-Store Model), it is processed by three different stores or 'slave systems'
• Dual Task Performance


  People are able to do one visual and one verbal task simultaneously with their performance being relatively unimpaired (no interference), but when performing two visual or two verbal tasks simultaneously, performance is less well than if done separately
• Central Executive (CE)


  The component of the Working Memory Model that co-ordinates the activities of the three subsystems in memory and allocates processing resources
• Phonological Loop (PL)


  The component of the Working Memory Model that processes information in terms of sound, including both written and spoken material. It's divided into the phonological store and the articulatory process
• Visuo-Spatial Sketchpad (VSS)


  The component of the Working Memory Model that processes visual and spatial information in a mental space often called our 'inner eye'
• Episodic Buffer (EB)


  The component of the Working Memory Model that brings together material from the other subsystems into a single memory rather than separate strands, and provides a bridge between working memory and long-term memory
• Phonological loop (PL)


  The component of the WMM that processes information in terms of sound. This includes both written and spoken material. It's divided into the phonological store and the articulatory process.
• Visuo-spatial sketchpad (VSS)


  The component of the WMM that processes visual and spatial information in a mental space often called our 'inner eye'.
• Episodic buffer (EB)


  The component of WMM that brings together material from the other subsystems into a single memory rather than separate strands. It also provides a bridge between working memory and long-term memory.
• The working memory model focusses on short-term memory ONLY.
• Working memory


  That bit of memory you are using while working on a complex task which requires you to store information as you go along
• Components of the working memory model

  • The Central Executive (the boss)
  • Phonological Loop (PL) (a slave system)
  • Visuo-Spatial Sketchpad (VSSP) (a slave system)
  • Episodic Buffer (a slave system)
• The Central Executive


  • Coding: modality free (it can deal with information from any of the senses)
  • Capacity: very limited (it can only pay attention to a small amount of stimuli)
  • It decides what we selectively pay attention to
  • It sends information to the relevant stores/slave systems
  • It is active when dealing with cognitive tasks such as mental arithmetic, decision making and problem solving