8.1

Learning Objectives

By the end of this section, you will be able to:

  • Discuss the three basic functions of memory
  • Describe the three stages of memory storage
  • Describe and distinguish between procedural and declarative memory and semantic and episodic memory

Overview of Memory

Memory is an information processing system that is often likened to a computer. It consists of a set of processes used to encode, store, and retrieve information over different periods of time.

Functions of Memory

Memory has three fundamental functions:

  1. Encoding - The input of information into the memory system.
  2. Storage - The retention of the encoded information.
  3. Retrieval - Getting the information out of memory and back into awareness.

![Memory Encoding, Storage, and Retrieval](Figure 8.2)

Encoding

Encoding is the process through which we get information into our brains. It involves labeling or coding received sensory information and organizing it with similar information, making connections to existing knowledge.

Types of Encoding

Encoding occurs in two primary ways:

  • Automatic Processing:

    • This is the unconscious encoding of details such as time, space, frequency, and meaning of words.
    • Example: Recalling what you had for lunch, studying for a test does require much effort.

  • Effortful Processing:

    • This requires explicit effort and attention to encode information.
    • Example: Learning to drive involves focused attention on numerous tasks (starting, stopping, turning).
Effective Encoding Techniques
  • Making information meaningful enhances memory recall. For example, sentences are better remembered when they are placed in context rather than when presented randomly.

Types of Encoding Processes

  1. Semantic Encoding
  • Involves encoding the meaning of words.
  • Demonstrated by William Bousfield (1935) where subjects recalled words in categories, indicating that they processed meanings during learning.
  1. Visual Encoding
  • Involves encoding of images. High-imagery words (e.g., "car", "dog") are easier to recall than low-imagery words (e.g., "level", "truth").
  1. Acoustic Encoding
  • Involves encoding the sounds of words, often through rhyme or music aiding recall (e.g., learning the alphabet through song).
Research Comparison of Encoding Types

Fergus Craik and Endel Tulving (1975) found that words encoded semantically were better remembered than those processed visually or acoustically. Semantic encoding, particularly via the self-reference effect (deeper personal connection), improves memory retention.

Storage

Once information is encoded, it must be retained. Memory storage involves creating a permanent record of the information. For information to reach long-term memory, it passes through the following stages:

  1. Sensory Memory
  2. Short-Term Memory
  3. Long-Term Memory

Memory Stages

  • Atkinson-Shiffrin Model (1968): This model proposes that memories transition through sensory, short-term, and long-term stages, akin to computer file processing.
  • Baddeley and Hitch Working Memory Model (1974): Proposes different forms of short-term memory, suggesting that short-term memory functions like multiple files being processed in a computer:
    • Visuospatial sketchpad
    • Phonological loop
    • Episodic buffer
Sensory Memory
  • Stores brief sensory events (sights, sounds, tastes) for a couple of seconds.
  • Example: The insignificant details of everyday experiences are typically discarded unless deemed valuable.
Short-Term Memory
  • Temporary storage for sensory information, lasting 15 to 30 seconds. It is associated with working memory.
  • Rehearsal Techniques:
    1. Active Rehearsal: Repeating information to transfer it to long-term memory (e.g., repeating an alphabet).
    2. Elaborative Rehearsal: Linking new information to what is already known.
  • Capacity of Short-Term Memory: Research by George Miller suggests a capacity of 7 ± 2 items, while contemporary studies indicate approximately 4 ± 1 items.
  • Influential factors on retention include memory trace decay (Peterson & Peterson, 1959) and proactive interference.
Long-Term Memory
  • Continuous storage believed to be unlimited.
  • Organization: Memories are organized in semantic networks: connected concepts that enable easier retrieval due to spreading activation from associated links.
  • Types of Long-Term Memory:
    1. Explicit (Declarative) Memory
    • Involves conscious recall of information (e.g., studying). Split into:
    • Episodic Memory: Personal experiences or events. (Example: memories of birthday events)
    • Semantic Memory: Factual knowledge (Example: definitions of psychology).
    1. Implicit Memory
    • Non-conscious recall demonstrated through performance (e.g., riding a bike).
    • Examples include procedural, priming, and emotional conditioning memories.

Examples of Implicit Memory Types

  1. Procedural Memory: Knowledge of how to perform tasks.
  2. Priming: Exposure to stimuli influences responses to later stimuli.
  3. Emotional Conditioning: Associates specific emotional responses with different stimuli.

Autobiographical Memories

  • Hyperthymesia: Exceptionally detailed autobiographical memory; very few individuals possess this quality.

Retrieval

Retrieval is the process of recalling stored information back into conscious awareness, analogous to opening a saved document from a hard drive.

Types of Retrieval
  1. Recall: Accessing information without cues (e.g., essay tests).
  2. Recognition: Identifying information when encountered again (e.g., multiple choice tests).
  3. Relearning: Quickly reacquiring information previously learned (e.g., relearning a language long after initial studies).