Memory: Encoding, Storage, Retrieval (Key Concepts)
Encoding, Storage, and Retrieval (Three Basic Memory Processes)
- Encoding β Converting sensory input into a form the brain can store.
- Storage β Maintaining encoded information over time.
- Retrieval β Accessing stored information when needed.
Memory Stores (Three Main Stores)
- Sensory Memory
- Type of Info: Raw sensory input (visual, auditory, tactile)
- Duration: 0.2\text{ s} \;-\; 4\text{ s}
- Capacity: Very large but brief
- Short-Term Memory (STM)
- Type of Info: Current thoughts / working information
- Duration: 18-30\text{ s} (without rehearsal)
- Capacity: 7 \pm 2 items
- Long-Term Memory (LTM)
- Type of Info: Permanent knowledge & experiences
- Duration: Potentially lifelong
- Capacity: Unlimited
Information Processing Model (Flow)
1) Sensory Input β Sensory Memory (attention needed to move on)
2) Attention β Short-Term Memory (STM holds current info)
3) Encoding β Long-Term Memory (via rehearsal & processing)
4) Retrieval β Back to STM when needed
- Key Steps:
- Attention: Focus on information to move it into STM.
- Rehearsal/Processing: Deep thinking or repetition to move into LTM.
- Retrieval Cues: Triggers to bring LTM into STM for use.
Holding Information in STM
- Chunking β Grouping items into meaningful units.
- Maintenance Rehearsal β Repeating information over and over.
- Elaboration Rehearsal β Linking new information to existing knowledge for deeper encoding.
Serial Position Effect
- Primacy Effect β Better recall for early items (LTM).
- Recency Effect β Better recall for recent items (STM).
Types of Long-Term Memory
- Procedural β Skills & habits (e.g., riding a bike).
- Declarative β Facts & events
- Semantic β General knowledge (e.g., capital of France).
- Episodic β Personal experiences (e.g., first day of school).
Brain Regions in Memory
- Hippocampus β Formation of new declarative memories.
- Amygdala β Emotional memory processing.
- Cerebellum β Procedural memories & motor skills.
- Case of HM β Hippocampus removed β could form procedural but not new declarative memories.
Types of Retrieval
- Recall β Producing information without cues.
- Recognition β Identifying information from options.
- Re-learning β Learning again; faster than first time.
Retrieval Cues
- State-dependent β Same mood/physiological state aids recall.
- Context-dependent β Same environment aids recall.
Semantic Networks
- Memory is organized in interconnected nodes (concepts linked by meaning).
- Example: βDogβ linked to βpet,β βbarks,β βfur,β etc.
Key Experiments
- Ebbinghaus β Forgetting curve: rapid initial loss, then levels off.
- Bartlett β Schema theory: memories reconstructed to fit existing beliefs.
Why False Memories Occur
- Misleading information, suggestion, schema-driven distortions, imagination inflation.
Reasons for Forgetting
- Biological β Brain injury, illness, drugs, aging.
- Psychological β Motivated forgetting (repression).
Encoding & Retrieval Failure
- Encoding failure β Never stored properly.
- Retrieval failure β Stored, but cues are missing.
Theories of Forgetting
- Natural Decay β Memory fades if unused.
- Proactive interference β Old information interferes with new learning.
- Retroactive interference β New information interferes with old learning.
- Consolidation Theory β Memory needs time & sleep to stabilise.
Levels of Processing Theory
- Deeper (semantic) processing β better retention than shallow (surface-level) processing.
Memory Enhancement Techniques
- Self-Referential Effect β Relate information to yourself.
- Spaced Learning/Repetition β Study in intervals.
- Method of Loci β Use a familiar location to place mental βitems.β
- Narrative Chaining β Make a story linking items.
- Elaboration β Add detail & associations.
- Mnemonics β Peg-words, rhymes, acronyms, acrostics.