"The advantage of bad memory is that one enjoys several times, the same good things for the first time." — Friedrich Nietzsche
Introduction
Memory is central to almost all cognitive processes like perception, thinking, and problem-solving. It preserves our sense of identity, maintains relationships, and helps in decision-making. This chapter explores how information is committed to memory, retained, sometimes lost, and how it can be improved.
Nature of Memory
Memory involves three interrelated processes:
- Encoding: Recording information for first-time use by the memory system
- Storage: Retaining information over time
- Retrieval: Bringing stored information to awareness when needed
Memory failure can occur at any of these stages due to improper encoding, weak storage, or retrieval difficulties.
Information Processing Approach: The Stage Model
Atkinson and Shiffrin's 1968 model compares human memory to computer processing with three memory systems:
The Stage Model of Memory
Memory Systems
- Sensory Memory:
- Large capacity but very short duration (<1 second)
- Registers exact replicas of sensory inputs
- Includes iconic (visual) and echoic (auditory) memory
- Short-term Memory (STM):
- Limited capacity (7±2 items) and duration (~30 seconds)
- Primarily encoded acoustically (by sound)
- Includes working memory components (see Box 6.1)
- Long-term Memory (LTM):
- Vast, potentially unlimited capacity
- Semantic encoding (by meaning) makes memories durable
- Information is never truly forgotten, only retrieval fails
Working Memory (Box 6.1)
Baddeley's multi-component model of STM includes:
- Phonological Loop: Holds sounds (decays in ~2 seconds)
- Visuospatial Sketchpad: Stores visual/spatial information
- Central Executive: Manages attention and information flow
Control Processes
Mechanisms that monitor information flow between memory stores:
- Selective Attention: Determines what enters STM from sensory memory
- Maintenance Rehearsal: Repetition to retain information in STM
- Chunking: Grouping information to expand STM capacity (e.g., 1947-1949-2004 as historical dates)
- Elaborative Rehearsal: Connecting new information to existing knowledge for transfer to LTM
Activity 6.1
Demonstrate chunking by memorizing digits as individual numbers, in groups, and as squares (1² 3² 5² 7² 9² 11²). Test digit span recall with friends using lists of increasing length.
Levels of Processing
Craik and Lockhart's (1972) theory suggests memory retention depends on processing depth:
- Structural (Shallow): Processing physical features (e.g., letter shapes in "cat")
- Phonetic (Intermediate): Processing sound patterns
- Semantic (Deep): Processing meaning (e.g., "cat" as furry, four-legged mammal)
Deeper processing leads to more durable memories.
Types of Long-term Memory
Major Classifications
- Declarative vs. Procedural:
- Declarative: Facts and events (can be verbalized)
- Procedural: Skills and procedures (hard to describe)
- Episodic vs. Semantic:
- Episodic: Personal life experiences (emotional)
- Semantic: General knowledge and facts (neutral)
Long-term Memory Phenomena (Box 6.2)
- Flashbulb Memories: Vivid, detailed memories of surprising/emotional events
- Autobiographical Memory: Uneven distribution with childhood amnesia and reminiscence bump in early adulthood
- Implicit Memory: Unconscious memories that influence behavior (e.g., typing without being able to draw keyboard)
Activity 6.2
Compare vivid early school memories with recent Class XI memories in terms of length, emotions, and coherence.
Methods of Memory Measurement (Box 6.3)
- Free Recall & Recognition: Recall learned items or recognize them among distractors
- Sentence Verification: Test speed of verifying true/false statements (for semantic memory)
- Priming: Measure speed of completing word fragments seen earlier (for implicit memory)
Activity 6.3
Test levels of processing by having participants answer questions about words (structural, phonetic, semantic) and later recall them.
Nature and Causes of Forgetting
Ebbinghaus's Forgetting Curve
Forgetting is rapid initially (first hour) then slows down, with about 60% lost in first 9 hours but little after 30 days.
Theories of Forgetting
- Trace Decay (Disuse Theory):
- Memory traces fade with disuse
- Problems: Sleep leads to less forgetting than being awake
- Interference Theory:
- New memories interfere with old ones
- Proactive: Old learning interferes with new (e.g., English making French harder)
- Retroactive: New learning interferes with old (e.g., French making English harder)
Type Phase 1 Phase 2 Testing Phase Retroactive Learn A Learn B Recall A Proactive Learn A Learn B Recall B - Retrieval Failure:
- Absence of appropriate retrieval cues
- Example: Category names dramatically improve recall of word lists
Repressed Memories (Box 6.4)
Freud suggested traumatic memories may be repressed into unconsciousness. Extreme stress can cause:
- Psychological Amnesia: Forgetting under extreme stress
- Fugue State: Assuming new identity with no memory of old
Activity 6.4
Compare recall of two animal word lists after delay, testing interference effects between similar materials.
Enhancing Memory
Mnemonic Strategies
- Using Images:
- Keyword Method: Associate foreign words with similar-sounding native words and images (e.g., Spanish "pato" (duck) with "pot" → duck in pot)
- Method of Loci: Associate items with locations in a familiar place (e.g., shopping list items in different rooms)
- Using Organization:
- Chunking: Group items meaningfully (e.g., phone numbers as chunks)
- First Letter Technique: Create acronyms (e.g., VIBGYOR for rainbow colors)
Comprehensive Memory Improvement
- Deep Level Processing: Focus on meaning and relationships to existing knowledge
- Minimize Interference: Space out study of similar subjects
- Use Retrieval Cues: Create and use meaningful associations
- PQRST Method: Preview, Question, Read, Self-recitation, Test
Note: Memory improvement requires attention to multiple factors including health, interest, and motivation.
Key Terms
Encoding: Initial registration of information
Storage: Retention of information over time
Retrieval: Recovery of stored information
Sensory Memory: Brief storage of sensory impressions
Short-term Memory (STM): Limited capacity temporary store
Long-term Memory (LTM): Permanent, unlimited capacity store
Working Memory: Active processing components of STM
Declarative Memory: Memory for facts and events
Procedural Memory: Memory for skills and procedures
Episodic Memory: Personal life experiences
Semantic Memory: General knowledge and facts
Interference: Competition between memories causing forgetting
Mnemonics: Strategies for improving memory
Summary
- Memory involves encoding, storage, and retrieval processes
- The Stage Model describes sensory, short-term, and long-term memory systems
- Deeper (semantic) processing leads to better retention than shallow processing
- Long-term memory includes declarative/procedural and episodic/semantic types
- Forgetting follows Ebbinghaus's curve and may result from decay, interference, or retrieval failure
- Memory can be enhanced through mnemonics (imagery and organization) and deeper processing strategies
Review Questions
- Explain the three basic processes of memory (encoding, storage, retrieval).
- How does information flow through sensory, short-term, and long-term memory systems?
- Differentiate between maintenance and elaborative rehearsals.
- Compare declarative and procedural memory with examples.
- What are the main causes of forgetting according to psychological research?
- How does retrieval failure differ from interference as explanations of forgetting?
- Define mnemonics and suggest practical strategies to improve your memory.
Project Idea
Recall and write down a vivid personal event. Have others who participated in the same event write their recollections. Compare versions for similarities and discrepancies, analyzing reasons for differences in memory.