Memory

• Multi-store model of memory

  A model that suggests memory is broken down into 3 components: sensory register, short-term memory, and long-term memory
• Sensory register


  • Incoming information from the senses received in the sensory store
  • Capacity: unlimited
  • Duration: 0.5-3 seconds
  • Coding: any modality
  • Forgetting: decay
• Short-term memory (STM)


  • Temporary store where small amounts of information can be kept for brief periods
  • Capacity: 7±2 chunks of information
  • Duration: 15-30 seconds
  • Coding: acoustic
  • Forgetting: displacement
• Long-term memory (LTM)


  • Permanent store where limitless amounts of information can be stored for long periods of time
  • Capacity: unlimited
  • Duration: from a few minutes to a lifetime
  • Coding: semantic (through meaning)
  • Forgetting: interference or decay
• Transfer of information


  1. Sensory register -> Short-term memory (if attended to)

  2. Short-term memory -> Long-term memory (if rehearsed)
• The multi-store model proposes that rehearsal is the only means of transferring information from STM to LTM
• Primacy effect


  People are likely to remember more words from the beginning of a list
• Recency effect


  People are likely to remember more words from the end of a list
• The primacy and recency effects provide evidence for separate STM and LTM with different capacities and durations
• The case of patient HM supports the idea of separate STM and LTM stores
• Rehearsal may not be as important as the multi-store model claims for information to pass from STM to LTM
• Research suggests the LTM and STM are not unitary stores as proposed by the multi-store model
• Episodic memory


  Memory for personal experiences and events, including specific details, context, and associated emotions
• Semantic memory


  Memory for general knowledge and facts about the world
• Procedural memory

  Memory for skills and procedures, often implicit and automatic
• The case of HM supports the idea of separate LTM types (episodic, semantic, procedural)
• The case of Clive Wearing also supports the idea of separate LTM types
• Brain scanning research shows different brain areas are associated with different LTM types
• Cohen and Squire disagree with the suggestion that there are 3 types of LTM, only accepting procedural memory
• Procedural memory


  Memories of how to do things, such as playing the piano
• Episodic memory


  Memories of personal events and experiences
• The patient had no memories of personal events that occurred since the infection
• Research into long-term memory (LTM)

  • The distinction between 3 kinds of LTM (episodic, semantic, procedural) is supported by brain scanning research
  • Different areas of the brain are active for different types of LTM
• Declarative memories


  Memories which can be consciously recalled and put into words
• Non-declarative (procedural) memories


  Memories which cannot be put into words
• Working Memory Model


  Proposed by Baddeley and Hitch, suggests STM is not a single store but multiple components
• Components of the Working Memory Model

  • Central Executive
  • Phonological Loop
  • Visuospatial Sketchpad
  • Episodic Buffer
• Central Executive


  • Pays attention to incoming information and directs it to other components
  • Involved in higher mental processes like decision making
  • Has limited capacity and is modality-free
• Phonological Loop


  • Consists of Phonological Store (stores acoustically coded information) and Articulatory Process (allows sub-vocal rehearsal)
  • Has limited capacity of about 2 seconds of speech
• Visuospatial Sketchpad


  • Processes visual and spatial information, including movement and images
  • Can be subdivided into Visual Cache and Inner Scribe
• Episodic Buffer


  • Provides general storage, combining information from other components and LTM
  • Maintains sense of time sequencing
  • Limited capacity of about 4 chunks
• Strengths of the Working Memory Model

  • Supported by research on patient KF who had intact LTM but difficulties with STM
  • Supported by dual-task studies showing separate components
  • Supported by brain imaging research showing different brain areas activated for verbal vs visual tasks
• Weaknesses of the Working Memory Model

  • Does not explain how information passes from STM to LTM
  • Insufficient detail on the functioning of the Central Executive
• Proactive interference


  When information stored previously interferes with recall of new information
• Retroactive interference


  When new information disrupts recall of previously stored information
• Proactive interference was demonstrated by Keppel and Underwood using recall of consonant trigrams
• Retroactive interference was demonstrated by Schmidt using recall of childhood neighborhood street names</b>
• Strengths of research on interference

  • Supported by Baddeley and Hitch's research showing forgetting depends on number of games played, not time elapsed
• Weaknesses of research on interference

  • Ignores individual differences in susceptibility to interference
  • Interference only explains some situations of forgetting, not everyday forgetting
  • Artificial tasks used in studies may lack external validity
• Retrieval failure due to absence of cues


  People may forget information due to lack of meaningful links or environmental/internal cues to aid recall