3-System Model of Memory

• The 3-system model of memory includes sensory, short-term, and long-term stores.
• Information transfers between these stores via attention, encoding, and retrieval processes.

Memory Systems: Capacity and Duration

• Sensory Memory: Large capacity, very short duration (milliseconds to seconds).
• Short-Term Memory: Limited capacity (around 7 items), short duration (seconds to minutes) without rehearsal.
• Long-Term Memory: Virtually unlimited capacity, potentially permanent duration.

Sensory Memory

• Briefly holds sensory information.
• Iconic memory: Visual sensory memory.
• Echoic memory: Auditory sensory memory.

Short-Term Memory (STM)

• Holds information temporarily for analysis.
• Limited capacity, approximately 7 +/- 2 items, is the "Magic number" that defines how much can be stored at any given time.
• Relies on rehearsal to maintain duration.
• Can be extended through chunking.

STM Duration

• Without rehearsal, lasts only a few seconds.
• Trigram experiment: Demonstrates rapid decay of information in STM when rehearsal is prevented.
• Memory Span Test: Determines the capacity of STM by measuring the number of items a person can immediately recall in correct order.

Improving STM

• Rehearsal: Actively repeating information to maintain it in STM.
• Chunking: Grouping individual pieces of information into larger, meaningful units to increase STM capacity.

Forgetting in STM

• Decay: Information fades away over time if not attended to.
• Interference: New information displaces old information.

Long-Term Memory (LTM)

• A virtually limitless storehouse of information.
• Encoding is the process of transferring information from short-term to long-term memory.
• Retrieval is the process of bringing information from long-term memory into conscious awareness.

Serial Position Effects

• Evidence for distinction between STM and LTM.
• Primacy effect: Better recall of items at the beginning of a list (LTM).
• Recency effect: Better recall of items at the end of a list (STM).

Types of Long-Term Memory

• Explicit memory: Consciously recalled.
  • Episodic memory: Personal experiences and events.
  • Semantic memory: Facts and general knowledge.
• Implicit memory: Not consciously recalled; influences behavior.
  • Procedural memory: Skills and habits.
  • Priming: Exposure to a stimulus influences response to a later stimulus.

Amnesia

• Memory loss due to brain damage.
• Anterograde amnesia: Inability to form new memories after the onset of amnesia.
• Retrograde amnesia: Loss of memories from before the onset of amnesia.

Cases Studies in Amnesia

• Patient H.M.: Suffered severe anterograde amnesia after hippocampus removal.
• Clive Wearing: Extensive damage to hippocampus and frontal lobes, resulting in profound anterograde and retrograde amnesia.
• Hippocampus: Critical for forming new explicit memories, but not for retrieving old memories or forming new implicit memories.

Encoding Processes

• Attention: Focusing awareness on information.
• Depth of Processing: The more deeply information is processed, the better it is encoded.
• Distributed Practice: Spacing out study sessions over time.
• Mnemonics: Memory aids that use imagery or organization.
  • Method of Loci: Associating items with locations in a familiar place.
  • Pegword Method: Associating items with rhyming words or images.
  • Keyword Method: Associating foreign words with similar-sounding English words and images.

Memory Storage

• Schemas: Mental frameworks that organize and interpret information; can influence how memories are stored and retrieved.

Retrieval Processes

• Retrieval Cues: Stimuli that help access memories.
• Recall: Retrieving information without cues.
• Recognition: Identifying previously learned information from options.
• Encoding Specificity: Retrieval is best when the context at retrieval matches the context at encoding.
• Context-Dependent Memory: Improved recall when in the same environment as when the information was learned.
• State-Dependent Memory: Improved recall when in the same emotional or physical state as when the information was learned.
• Tip-of-the-Tongue Phenomenon: Feeling of knowing something without being able to retrieve it.

Memory Illusions

• Memory is a reconstructive process, subject to distortions and errors.
• Flashbulb Memories: Vivid, detailed memories of emotional events.
• Source Monitoring Confusion: Misattributing the source of a memory.
• Misinformation Effect: Incorporation of false information into memories after exposure to misleading information.
• Imagination Inflation: Imagining an event increases confidence that it actually happened.
• Cryptomnesia: Unconsciously plagiarizing someone else's ideas or work.