Psychology Chapter on Memory

Memory

• Memory: The ability to store and retrieve information.
• Sensory Memory: Briefly holds sensory information (visual, auditory, etc.).
  • Capacity: Large
  • Duration: Very short (milliseconds to seconds)
  • Sperling's Partial Report Method: Demonstrated the existence of sensory memory by testing participants' ability to recall a portion of a briefly presented array of letters.
• Short-Term Memory: Holds information for a short period of time (seconds to minutes).
  • Capacity: Limited (typically around 7 items, +/- 2)
  • Duration: Short (seconds to minutes)
  • Atkinson-Shiffrin Model: Proposed a three-stage model of memory - sensory memory, short-term memory, and long-term memory.
• Working Memory: A more active system that manipulates and processes information from short-term memory.
  • Baddeley's Working Memory Model: Proposed a working memory system with different components, including:
    • Phonological Loop: Processes verbal and auditory information.
    • Visuospatial Sketchpad: Processes visual and spatial information.
    • Central Executive: Controls attention and integrates information from other components.
  • Factors Affecting Working Memory:
    • Phonological Similarity Effect: Words that sound similar are harder to recall than words that sound different.
    • Word Length Effect: Shorter words are easier to recall than longer words.
    • Articulatory Suppression: Reciting irrelevant words disrupts the ability to hold information in the phonological loop.

Long-Term Memory

• Long-Term Memory: Stores information relatively permanently (minutes to years).
  • Capacity: Essentially unlimited.
  • Duration: Long-lasting (minutes to years)
• Brain Stimulation and Memory:
  • Penfield's Work: During brain surgery, electric stimulation of specific brain regions could evoke memories in patients.
• Types of Long-Term Memory:
  • Explicit Memory: (Conscious memory)
    • Semantic Memory: General knowledge about the world (facts, concepts).
    • Episodic Memory: Personal experiences and events.
    • Procedural Memory: Memory for skills and habits.
  • Implicit Memory: (Unconscious memory)
    • Priming: Recent exposure to a stimulus makes it easier to process the same or similar stimulus later.
    • Conditioning: Learning associations between stimuli and responses.
• Semanticization of LTM: The gradual loss of detailed episodic information, leaving only the semantic gist of the memory.
• Propaganda Effect: Increased familiarity with a statement leads to a greater likelihood of believing it.
• Neural Structures and Memory:
  • Explicit Memory: Hippocampus, amygdala, and prefrontal cortex.
  • Implicit Memory: Basal ganglia, cerebellum, and motor cortex.
• Tests of Implicit and Explicit Memory:
  • Explicit Memory Tests: Recall and recognition tasks.
  • Implicit Memory Tests: Word-stem completion, perceptual identification tasks.
• Amnesia: Loss of memory.
  • Retrograde Amnesia: Loss of memories from before the onset of amnesia.
  • Anterograde Amnesia: Inability to form new memories after the onset of amnesia.
  • **Patient H.M., Clive Wearing, E.P.: ** Famous cases of amnesia that have provided critical insights into memory systems.
  • Functions Spared in Amnesia: Often, implicit memory, procedural memory, and semantic memory remain intact.
• Memory Processes:
  • Encoding: Getting information into memory.
    • Levels of Processing Theory: Deeper processing (meaningful processing) leads to better memory.
    • Encoding Specificity Principle: Retrieval cues are more effective if they relate to the way in which information was encoded.
    • Ebbinghaus's Study: Demonstrated the forgetting curve, showing that memory decays over time.
  • Consolidation: Making memories more stable and enduring.
    • Synaptic Consolidation: Strengthening of synaptic connections involved in the memory.
    • Systems Consolidation: Transfer of memories from the hippocampus to other brain regions for long-term storage.
      • Standard Model: The hippocampus is initially critical for consolidation, but its role diminishes over time.
      • Multiple Trace Model: The hippocampus is always involved in retrieving episodic memories.
  • Retrieval: Accessing and retrieving information from memory.
    • Hebbian Learning: Neurons that fire together wire together.
    • Long-Term Potentiation (LTP): A persistent strengthening of synapses due to repeated stimulation.
    • Neurotransmitters and Receptors: Glutamate and NMDA receptors play crucial roles in learning and memory.
    • Retrieval Cues: Stimuli that help retrieve information from memory.
    • Mood and State-Dependent Retrieval: Memory retrieval is better if the internal state (e.g., mood, intoxication) at retrieval matches the state at encoding.

Other Memory Concepts

• Serial Position Effect: The tendency to remember items at the beginning (primacy effect) and end (recency effect) of a list better than items in the middle.
• Ways to Enhance Encoding:
  • Rehearsal: Repeating information.
  • Generation Effect: Generating information yourself, rather than passively receiving it, leads to better memory.
  • Elaboration: Adding meaning and context to information.
• Factors Affecting Encoding and Retrieval:
  • Attention: Focused attention enhances encoding.
  • Motivation: High motivation leads to better encoding.
  • Emotions: Strong emotions can enhance or impair memory.
  • Sleep: Consolidation occurs during sleep.
• Remember/Know Procedure: A test of memory that asks participants to judge whether they have encountered a specific item before (remember) or simply feel familiar with it (know).
• Recall vs. Recognition:
  • Recall: Retrieving information without any cues.
  • Recognition: Identifying previously encountered information.
• Testing Effect: Repeatedly testing oneself on material leads to better long-term memory.