Memory Models and Spatial Metaphor

Spatial Metaphor of Memory

• Spatial metaphor of memory is comparing memory to something else - using an analogy.
• This helps researchers ask questions about memory.
• Most models of memory compare it to a space - things can be put in and taken out, with different characteristics.
• Atkinson and Shiffrin (1968) model of memory - divides memory into three parts:
  • Long-term store (long-term memory) - high capacity, lasts long time
  • Short-term store (working memory) - limited capacity, lasts short time
  • Sensory store - brief impression from sensory stimuli
• Working memory and long-term memory are independent; they can operate separately.
• Atkinson and Shiffrin's model doesn't include episodic and semantic memory, which was later proposed by Tulving (1972).
• Tulving's first distinction of semantic and episodic memory was about self-referential component, including time, place and self for episodic memory.
• Tulving's later definition (1985) emphasizes that episodic memory allows for re-living the experience, while semantic memory doesn't.
  • Episodic memory gives sense of mental time travel, reliving the experience.

Susan Bower Study

• This study found that episodic memory helps update trait summaries based on new information.
• Participants saw an image of a woman and learned new information about her.
• One group learned pleasant information that was later contradicted by another piece of information (e.g., having a boyfriend and a husband).
• The other group was given the contradictory information a month later, and their impression of the woman didn't change.
• The study suggests that episodic memory helps integrate new information with previous knowledge and update judgments about individuals.

Serial Position Curve Studies

• These studies show how the position of an item in a list affects the probability of remembering it.
• Words in the beginning and end of a list are remembered better than those in the middle.
• This is because:
  • The first few items are repeated during the list presentation and encoded more deeply.
  • The last few items are still in working memory when tested, so easier to recall.

Readings Overview

• Chapter 5:

  • Boss Fields' study on clustering and memory performance.
  • Adjusted Ratio of Clustering (ARC) - measures the extent of clustering in recall.
  • People with more clusters in recall remember more words - memory organization is linked to better memory.

• Chapter 6:

  • Focuses on mnemonics - techniques used to enhance memory.
  • Mnemonists (people with exceptional memory) use techniques that are theoretically learnable by anyone, not just exceptional skill.
  • Methods include:
    • Reduction coding (e.g., Roy G. Biv for rainbow colours)
    • Elaboration coding (adding information to make something memorable, such as using imagery).
    • Method of Loci (imagining a familiar place and associating items with different locations).

• Chapter 7:

  • Klein's article on the definition of memory.
  • Traditional view of memory - encoding, storage, retrieval
  • Klein believes this definition is too broad and doesn't account for other mental processes like imagination.
  • Klein proposes that memory is only authentic when it's experienced as from and about one's past.
  • Klein equates episodic memory with true memory and excludes semantic memory.

Long-term Memory

• Encoding Specificity Principle:

  • Memory is better when retrieval conditions match encoding conditions.
  • This includes mental states - people remember drunk conversations better when drunk.
  • Example: Word lists learned underwater are remembered better underwater than on land.

• Theories of Forgetting:

  • Interference:

    • Forgetting occurs due to overlapping memories interfering with each other.
    • Proactive interference: Previous memories interfere with learning new information.
    • Retroactive interference: New memories interfere with remembering old information.

  • Decay: Memories simply fade away over time.

• Wickens study on proactive interference in working memory:

  • Proactive interference occurs even in working memory.
  • People were given lists of syllables, with a distractor task between, recall deteriorated over time.
  • Changing the stimulus type (from letters to numbers) improved recall, showing interference from similar items.

• Depth of Processing:

  • Semantically processed information is remembered better than material processed shallowly (e.g., orthographically).
  • The problem with this theory is that it's circular - semantic encoding is associated with better memory because it's more deeply processed, and we know it's more deeply processed because it's remembered better. It doesn't have an independent measure of depth.

Depth of Processing Theory

• The depth of processing theory states that information is encoded more deeply when processed semantically, resulting in better memory.
• However, the theory is criticized for being circular due to its reliance on memory performance as the sole measure of "deep" processing.
• The criticism highlights that the theory defines "deep" processing solely based on how well information is remembered, leading to a circular definition.

Memory Improvement Techniques

• Organization:
  • Involves creating links or associations between items to be remembered.
  • Examples include categorizing items based on shared characteristics or using mnemonic techniques like the Method of Loci.
• Elaboration:
  • Involves forming connections between items to be remembered and existing knowledge or personal experiences.
  • Examples include creating meaningful stories or generating associations between words and personal memories.

Amnesias

• Patient H.M.:
  • Suffered from anterograde amnesia after an operation to remove the medial temporal lobes.
  • Inability to form new episodic memories while retaining older memories.
• Patient R.B.:
  • Suffered from anterograde amnesia following a bicycle accident.
  • Maintained episodic memories but lacked a sense of personal ownership of them, experiencing them as if they were external information.
• Patient K.C.:
  • Suffered from both anterograde and retrograde amnesia following a motorcycle accident.
  • Despite inability to form new episodic memories, could accurately describe personal traits, highlighting the possible distinction between semantic and episodic memory.
• Patient D.B.:
  • Experienced anterograde amnesia and difficulty with semantic facts prior to his accident.
  • Unable to imagine himself in the future but could imagine future events in a general sense.

Exceptional Memories

• Patient S:
  • Russian individual with exceptional memory studied by psychologist A.R. Luria.
  • Demonstrated ability to recall extensive information and languages, including large lists of numbers and events in meetings.
  • Possessed synesthesia, associating senses like color or smell with numbers and words, allowing for vivid mental imagery.
• Patient S.F.:
  • College student who trained to increase his digit span by utilizing a running technique to chunk information.
  • Example of a purely technique-based strategy for improving memory.
• Elizabeth E. and Diami, the "Mental Camera":
  • Individuals who entertained audiences with their exceptional memories while performing memory tricks.
  • Representation of memory skills as a form of entertainment in the past.

Key Takeaways

• While depth of processing theory is a well-replicated finding, its circular definition raises questions about its validity.
• Effective memory improvement strategies include organization and elaboration.
• Amnesic patients demonstrate the complexity of memory systems, highlighting the distinction between episodic and semantic memory.
• Exceptional memories can be attributed to both innate ability and learned techniques.