4th Lecture_ Memory I – Models and Research Methods

Memory Overview

• What is Memory?

  • The process of retaining and retrieving past experiences.

  • Three key operations:

    1. Encoding: Transforming sensory input into a memory trace.

    2. Storage: Retaining encoded information.

    3. Retrieval: Accessing stored information when needed.

Measuring Memory

• Recall vs. Recognition:

  • Recall: Reproducing information from memory (e.g., essay questions).

    • Serial Recall: In exact order.

    • Free Recall: In any order.

    • Cued Recall: Given a hint or related item.

  • Recognition: Identifying previously learned information (e.g., multiple-choice).

• Implicit vs. Explicit Memory:

  • Explicit Memory: Conscious recall of facts/events.

  • Implicit Memory: Unconscious recall (e.g., skills, habits).

Models of Memory

1. Atkinson-Shiffrin Model (1968)

   • Sensory Store: Brief capture of stimuli.

   • Short-Term Memory (STM):

     • Lasts seconds to minutes (~30 sec).

     • Capacity of 7 ± 2 items.

   • Long-Term Memory (LTM):

     • Permanent storage.

     • Permastore: Extremely durable knowledge (e.g., language, math).

2. Levels-of-Processing Model (Craik & Lockhart, 1972)

   • Memory is based on depth of encoding:

     • Shallow Processing: Basic features (e.g., capitalization).

     • Phonological Processing: Sound-based (e.g., rhyming).

     • Deep (Semantic) Processing: Meaning-based (e.g., category classification).

   • Self-Reference Effect: Deeper recall when relating info to oneself.

3. Working Memory Model

   • Active mental workspace for processing information.

   • Articulatory Suppression: Repeating irrelevant sounds (e.g., "five") disrupts memory.

4. Connectionist Model (Neural Networks)

   • Memory stored as a network of connections between neurons.

Exceptional & Deficient Memory

• Exceptional Memory:

  • Mnemonists (e.g., "S.") – Individuals with extraordinary recall, often linked to synesthesia (mixing of senses, e.g., tasting words).

• Memory Deficits:

  • Amnesia:

    • Retrograde: Loss of past memories.

    • Anterograde: Inability to form new memories.

    • Infantile Amnesia: Inability to recall early childhood events.

  • Alzheimer’s Disease: Progressive memory loss due to brain atrophy, especially in the hippocampus, frontal, and temporal lobes.

How is Memory Stored?

• Explicit Memory: Facts and personal experiences.

• Procedural Knowledge: Skills and habits.

• Emotionally Charged Memories: Stored with influence from the amygdala.

• Cerebellum: Involved in classical conditioning and cognitive tasks.