Memory Essentials: Encoding, Storage, and Retrieval

Memory Basics

  • Memory is an efficient, not perfect, reconstructive process.
  • Memory consists of three core processes: encoding, storage, and retrieval.

Encoding

  • Levels of Processing (Craik & Lockhart, 1972): Deeper levels of processing lead to more effective encoding.
    • Shallow: Surface features (e.g., word appearance).
    • Intermediate: Phonemic features (e.g., word sound).
    • Deeper Semantic: Meaning, context, personal associations.
  • Dual Coding (Paivio, 1971): Encoding information both visually and verbally enhances memory.

Storage Systems

  • Sensory Memory: Brief storage of sensory information (e.g., Iconic memory for vision, Echoic memory for sound). Short duration, easily interfered with.
  • Short-Term Memory (STM): Limited capacity and duration.
    • Capacity: Miller (7extextpm27 ext{ extpm } 2 items), more recently suggested as 4extextpm14 ext{ extpm } 1 items (Cowan) due to chunking and rehearsal.
    • Forgetting: Primarily due to interference (proactive and retroactive), rather than decay alone.
  • Working Memory (WM): Active maintenance and manipulation of information. Often preferred over 'short-term memory'.
    • Baddeley's Model (2012): Components include Central Executive, Phonological Loop, Visuo-Spatial Sketchpad, and Episodic Buffer.
  • Long-Term Memory (LTM): Includes declarative and non-declarative memory.
    • Declarative Memory ("knowing that"): Conscious recall of facts and events.
      • Episodic Memory: Specific events, experiences, and temporal order.
      • Semantic Memory: General facts, concepts, and knowledge without temporal context (organized by clusters of ideas).
    • Non-Declarative Memory ("knowing how"): Unconscious memory for skills and procedures.
      • Procedural Memory: Skills and habits (e.g., riding a bike).
      • Also includes priming, classical conditioning, and non-associative learning.
    • Explicit vs. Implicit Memory: Explicit is conscious recall; implicit is unconscious knowledge.

Retrieval and Forgetting

  • Memory as Reconstructive: Memory is rebuilt each time it is retrieved, making it prone to errors and external influence.
    • Loftus's Work: Demonstrated the creation of false memories (e.g., getting lost at the mall), misinformation effects, and source-monitoring errors.
  • Ebbinghaus's Forgetting Curve: Shows rapid initial forgetting, followed by a slower decline in retention over time.
  • Flashbulb Memories: Vivid, highly confident memories of significant events (e.g., 9/119/11), but confidence often exceeds accuracy over time.
  • Retrieval Cues: External or internal stimuli that help access memories.
    • Context-Dependent Memory (Godden & Baddeley, 1975): Recall is better when the retrieval environment matches the encoding environment.
  • Types of Forgetting/Amnesia:
    • Anterograde Amnesia: Inability to form new memories after an event.
    • Retrograde Amnesia: Inability to recall memories from before an event.
  • Recognition vs. Recall: Recognition (e.g., MCQs) is generally easier than recall (e.g., short answer questions).