Modal Model of Memory: In-Depth Notes

Overview of the Modal Model of Memory

• Proposed by Richard Atkinson and Richard Shiffrin.
• Suggests three memory stores:
  • Sensory Register
  • Short Term Memory (STM)
  • Long Term Memory (LTM)
• Information flow is linear from sensory memory to short term memory to long term memory.

Sensory Memory

• First stage of memory storage.
• Information captured from senses (visual, auditory, etc.) is held briefly (hundreds of milliseconds).
  • For example: Light enters through eyes, sound through ears.
• Duration: Very short; typically between $0.25$ seconds to $2$ seconds.
• Capacity: Large; can hold $25$ or more items.
• Main types:
  • Iconic Memory: Visual information.
  • Example: Remembering basic details of an image like color and shape, but not meaning.
  • Echoic Memory: Auditory information.
  • Example: Remembering a sound for a brief period right after hearing it.
• Functionality: If attended, sensory memory transfers to short term memory; if not, it decays.
• Research Techniques:
  • George Sperling's experiments on iconic memory using whole and partial report methods.

Short Term Memory (STM)

• Holds small amounts of information actively for a short duration.
• Duration: Longer than sensory memory, typically lasts for seconds unless rehearsed (repeating information).
• Capacity: Limited; about $7$ pieces of information or items (the "Magic Number 7").
• Encoding Formats: Can be visual, auditory, or semantic.
• Usage: Important for learning, reasoning, and decision-making.
  • Example: Memorizing a phone number temporarily.

Long Term Memory (LTM)

• Largest memory store; potentially unlimited capacity and duration.
• Information can be stored indefinitely; includes detailed memories of events, skills, knowledge, etc.
  • Example: Personal experiences, details of past birthdays, places visited, feelings.
• Encoding Formats: Information can be semantic, visual, or procedural.
• Memory retrieval requires transferring information back to short term memory.

Key Features of Memory Stores

1. Independence: Three stores are independent of each other.
2. Differences in Capacity and Duration:
   • Sensory memory has high capacity but short duration.
   • Short term memory has limited capacity but longer duration.
   • Long term memory has vast capacity and duration.

Processes of Forgetting

• Information can be lost through:
  • Decay
  • Interference
• These processes are explored in further discussions on memory.

Changes in Memory Understanding

• Since 1968, the original model has been revised:
  • Memory is viewed as parallel processing with modules functioning simultaneously rather than a strict linear pathway.
• This represents a substantial evolution in the understanding of memory processes.