Memory Notes

Types of Memory

  • Episodic Memory: Memory for life events (e.g., family holiday).
  • Semantic Memory: Memory for facts (e.g., penguin is a bird).
  • Procedural Memory: Memory for skills or actions (e.g., inserting a SIM card).
  • Long-term memory (LTM) and short-term memory (STM) are processed by different brain areas.
    • Frontal lobe: Essential for STM.
    • Hippocampus: Involved in forming new semantic and episodic LTMs.
  • Brain damage case studies (e.g., Henry Molaison) demonstrate that long- and short-term memory are separate.

Three Key Processes of Memory

  • Encoding: Taking new information into memory (input).
  • Storage: Maintaining information in temporary or permanent memory; requires consolidation (revision, sleep).
  • Retrieval: Accessing stored information (output).
  • Memory is essential for completing tasks, solving problems, and making sense of new information.

Ways to Retrieve Information

  • Recognition: Comparing presented information to memory (e.g., multiple-choice test).
  • Cued Recall: Using a cue to remember (e.g., seeing initials to recall a name).
  • Free Recall: Retrieving information directly from memory without cues (e.g., essay exams).

How Memories are Formed

  • Link new information to existing knowledge.
  • Repeatedly retrieve information, spaced out over time.

The Multi-Store Model

  • Atkinson and Shiffrin's model includes three memory stores: sensory, short-term (STM), and long-term (LTM).
  • Each store differs in encoding, capacity, and duration.
  • Encoding means taking information into memory.

Sensory Memory

  • Brief duration.
  • Information is taken if a person pays attention to it and passes it to the STM.
  • Separate sensory store for each of the senses: visual, auditory, and so on.
  • Auditory store holds spoken words for around two seconds.
  • Visual sensory store has a brief duration that is less than one second but a large capacity.

Short-Term Memory (STM)

  • STM is used for active processing of information in everyday tasks.
  • Rehearsal is needed to transfer information from STM to LTM.
  • Limited duration (up to 30 seconds) and capacity (5-9 items).

Long-Term Memory (LTM)

  • LTM potentially lasts a lifetime and stores an unlimited amount of information.

Encoding in Each Store

  • Sensory memory encodes information via all five senses.
  • STM encodes information based on its sound (acoustic encoding).
  • LTM encodes information based on its meaning (semantic encoding).
  • Information can be converted to the appropriate type of encoding for each store.

Supporting Evidence for the Multi-Store Model of Memory

  • Serial Position Curve: Words at the start (primacy effect) and end (recency effect) of a list are better remembered.
  • Murdock (1962) supported the multi-store model of memory with experiment that found the primacy and recency effect.

Explaining Primacy and Recency Effects

  • Primacy Effect: Items at the start of a list are rehearsed and encoded into LTM.
  • Recency Effect: The last few items are still in STM.
  • Middle items are displaced from STM due to its limited capacity.

Reconstructive Memory

  • Remembering is an active process of building memories based on understanding (Bartlett).
  • People use existing schema knowledge to fill gaps in memories during retrieval.
  • 'Effort after meaning': Making sense of new information using past information.
  • LTM is based around schemas which are clusters of related meaningful information that people derive from life experience and which are influenced by their culture.

Factors That Affect Memory

  • Amnesia: Can result in forgetting episodic memories.
  • Interference: Mixing up similar events or information.
  • Context: Easier to remember things in the context they were learned.
  • Reviewing and self-testing helps consolidate information in LTM.
  • False memories are distorted or false recollections of events that did not happen.