mem lec3

Understanding Memory: Key Concepts

Key Concepts Overview

  • Short-Term Memory: Temporary storage for information, limited duration.

  • Working Memory: Cognitive system to store and manipulate information in real-time.

  • Long-Term Memory: Sustained storage of information with potentially unlimited capacity.

  • Learning: Process of acquiring knowledge through experience.

  • Remembering: Act of retrieving stored information.

  • Retrieval: Bringing stored information to consciousness.

  • Forgetting: Inability to recall information.

  • False Memories: Inaccurate recollections of past events.

  • Memory Disorders: Conditions affecting memory function.

Introduction to Memory

  • Definition: Memory is the mental capacity to encode, store, and retrieve information.

  • Importance: Essential for learning, decision-making, and the development of personal identity.

Basic Types of Memory

  • Sensory Memory:

    • Brief storage of sensory information.

    • Duration is very short; constantly receives information but most is not attended.

  • Short-Term Memory (STM):

    • Limited in both capacity and duration (approximately 20 seconds).

    • Primarily involves auditory encoding.

  • Long-Term Memory (LTM):

    • Potentially unlimited in both capacity and duration.

Key Terminology in Memory

  • Encoding:

    • The process of transforming information into a format suitable for storage.

    • Three primary encoding types:

    • Visual: Involves imagery.

    • Acoustic: Related to sound.

    • Semantic: Focuses on meaning.

  • Storage: Maintaining information over time.

  • Retrieval: Accessing stored information to bring it into consciousness.

Modal Model / Multi-Store Model of Memory

  • Atkinson–Shiffrin Model (1968):

    • Proposes three separate memory stores: sensory memory, short-term memory (STM), and long-term memory (LTM).

    • Information transfers linearly:

    1. Detected by senses → Sensory Memory

    2. Attended information → STM

    3. Given meaning (elaborative rehearsal) → LTM

  • Differences among Stores:

    • Vary in encoding processes, capacity limits, and duration.

Limitations of the Modal Model

  • Oversimplified representation of memory; more complex interactions exist.

  • Rehearsal’s role is significantly more intricate than originally theorized; individuals can remember without rehearsal and forget rehearsed material.

Working Memory Model: Baddeley and Hitch (1974)

  • Details how information is transferred between STM and LTM, emphasizing a dynamic process.

  • Central Executive:

    • The control system; organizes and prioritizes information.

  • Buffers:

    • Phonological Loop: Manages auditory information via a speech-based form; includes:

    • Phonological Store: Temporary storage for auditory inputs.

    • Articulatory Control System: Keeps items alive through rehearsal.

    • Visuospatial Sketchpad: Handles spatial and visual information; often referred to as the "inner eye."

    • Episodic Buffer (added in 2000): Integrates information from different sources and connects to LTM.

Evidence Supporting the Working Memory Model

  • Patient KF:

    • Suffered from STM impairment; could recall visual information but struggled with verbal info, indicating separate systems in memory.

  • Dual-Task Experiments: Showed limitations of the visuospatial sketchpad versus phonological loop in memory tasks.

  • Neuroimaging Studies: Demonstrated different brain region activations associated with different memory components, but also indicated areas of overlap.

Limitations of the Working Memory Model

  • Incomplete explanation of overall memory functions, focusing mainly on short-term processes without addressing LTM interactions.

  • The Central Executive lacks a clear definition and operationalization; difficult to measure its function.

  • Unspecified capacities for subsystems, reducing clarity on individual variances.

Alternative Perspectives on Memory Models

  • Cowan’s Embedded-Processes Model (1999):

    • Suggests working memory is a subset of activated long-term memory.

  • Engle’s Executive Attention Model (2002):

    • Focus on task-relevant information maintenance amidst distractions.

  • Oberauer’s Three-Component Model (2002):

    • Divides working memory into three levels, blurring lines with long-term memory.

  • Long-Term Working Memory (Ericsson & Kintsch, 1995):

    • Proposes experts form long-term working memory through practice.

Methods of Memory Retrieval

  • Free Recall: Participants generate memories without cues (e.g. listing words from memory).

  • Recognition: Participants identify items from a provided list (e.g. recognizing words).

Key Research Findings in Memory Processes

  • Serial Position Effect:

    • Memory recalls depend on item position within a sequence;

    • Primacy Effect: Early items are remembered better due to rehearsal.

    • Recency Effect: Last items are remembered well due to freshness in STM.