Module 20

Memory Processes

• Memory: Process of encoding, storing, and retrieving information.

  • Involves three key stages:

    • Encoding: Initial recording of information in a form usable to memory.

    • Storage: Maintenance of material saved in memory, crucial for later recall.

    • Retrieval: Locating and bringing stored material into awareness for use.

The Three System Memory Theory

• Proposed by Atkinson and Shiffrin (1968).

• Suggests three separate memory stores:

  • Sensory Memory:

    • Initial, momentary storage of information, lasts only an instant.

    • Retains an exact replica of the stimulus recorded briefly.

    • Types include:

      • Iconic Memory: Visual system retention.

      • Echoic Memory: Auditory information storage.

  • Short Term Memory (STM):

    • Holds information for 15-25 seconds.

    • Stores information by its meaning.

    • Can hold about 7 (±2) chunks of information.

    • Information must be rehearsed to retain longer.

  • Long Term Memory (LTM):

    • Stores information on a relatively permanent basis.

    • Capacity is vast and retrieval can be challenging.

Functions of Memory Stores

• Sensory Memory:

  • Briefly contains a precise replica of sensory input (e.g., smell, sound).

  • Importance lies in its ability to provide immediate information responses.

  • Must pass to STM for retention; otherwise, it is lost.

• Short Term Memory:

  • Processes raw sensory inputs meaningfully.

  • Information can be retained through rehearsal.

  • Rehearsal Types:

    • Maintenance Rehearsal: Simple repetition, keeps information in STM.

    • Elaborative Rehearsal: Links new information to existing knowledge for transfer to LTM.

Working Memory

• Contemporary theorists view STM as Working Memory:

  • Active processing system managing new and older material.

  • Comprises several parts:

    • Central Executive: Oversees and coordinates information.

    • Visual Store: Holds visual/spatial information.

    • Verbal Store: Processes language-related material.

    • Episodic Buffer: Integrates events and occurrences.

Long Term Memory Structure

• Modules of LTM:

  • Divided into:

    • Declarative Memory (Explicit): Factual information (names, dates).

      • Further divided into:

        • Semantic Memory: General knowledge and facts.

        • Episodic Memory: Personal experiences and events contextualized by time/space.

    • Procedural Memory (Implicit): Skills and habits; actions that can be performed without conscious thought.

Memory Retrieval and Semantic Networks

• Knowledge retrieval is enhanced by associations between memory items.

• Semantic Networks: Clusters of interconnected information, activating one concept may trigger related concepts.

• Spreading Activation: Process where thinking about a concept activates related memories.

Biological Basis of Memory

• Key Brain Structures:

  • Hippocampus: Consolidates memories, stabilizes during initial acquisition.

  • Amygdala: Processes emotional memories; enhances memory recall of emotionally charged events.

• Engram: Physical memory trace in the brain.

• Memory functioning may involve long-term potentiation, synaptic changes during memory formation.

Consolidation and Memory Disorders

• Memories stabilize over time through consolidation, which explains the gradual process of memory fixation.

• New insights into treating memory disorders and potential memory manipulation techniques are being developed to help those with traumatic memories.

Summary of Memory Types and Functions

• Memory: Process of encoding...

• Sensory Memory: Brief, precise, but fades quickly.

• Short Term Memory: Limited duration, requires rehearsal.

• Long Term Memory: Nearly unlimited capacity, includes declarative and procedural memories.

• Biological Bases: Redistributed across the brain, important structures include the hippocampus and amygdala.