Chapter 6: Memory

Overview of Memory

• Memory: An active system that processes information from the senses into a usable format, organizes, stores, and retrieves it.

3 Processes of Memory

1. Encoding: Mental operations performed on sensory information to transform it into a usable form.

2. Storage: Holding information for a certain period.

3. Retrieval: Accessing stored information in a usable form.

Models of Memory Processing

• Information-Processing Model: Compares the processing of information to computer memory, involving encoding, storage, and retrieval stages.

• Parallel Distributed Processing (PDP) Model: Processes information simultaneously across a network of neural connections.

• Levels-of-Processing Model: Suggests that deeper processing (understanding meaning) leads to better retention than shallower processing (e.g., focusing on physical characteristics).

Memory Systems

1. Sensory Memory

• Function: The first memory system, holding sensory information briefly.

  • Example: A door being open for a short time.

• Iconic Sensory Memory: Brief visual memory lasting a fraction of a second.

  • Example: Recognizing a shocking scene (like a pantless person).

  • Masking: New visual information pushes older information out quickly.

  • Eidetic Imagery: Ability to recall visual memories for 30+ seconds.

  • Importance of Iconic Memory: Aids in perceiving surroundings as stable and continuous.

2. Echoic Memory

• Function: Auditory sensory memory lasting 2-4 seconds, crucial for meaningful conversations.

  • Example: Realizing you need to remember what someone said moments later.

3. Short Term Memory (STM)

• Definition: System holding information for a brief period while actively used.

  • Lasts around 12-30 seconds without rehearsal.

• Selective Attention: Focusing on one stimulus among others.

  • Cocktail-party Effect: Ability to focus on one conversation while filtering others.

• Working Memory: Active processing in short-term memory, includes:

  1. Central Executive: Coordinates memory tasks.

  2. Visuospatial Sketchpad: Visual processing.

  3. Phonological Loop: Auditory processing.

• Capacity: George Miller's "Magical Number Seven" suggests STM can hold approximately 5 to 9 items.

Long Term Memory (LTM)

• Definition: Memory storage for prolonged periods, potentially unlimited.

  • Duration: Involves permanent changes in the brain related to memory formation.

  • Some memories may be inaccessible even if stored.

• Types of Long Term Memory:

  • Declarative (Explicit) Memory: Conscious knowledge,

    • Semantic Memory: General knowledge and facts.

    • Episodic Memory: Personal experiences and events.

  • Non-declarative (Implicit) Memory: Skills and habits not consciously accessed.

  • Anterograde Amnesia: Difficulty forming new long-term memories post-injury.

  • Retrograde Amnesia: Loss of memories before an injury.

Memory Processes

Retrieval

• Retrieval Cues: Stimuli that aid memory recall; the more cues, the better the recall.

• Priming: Activation of related concepts, improving memory performance.

• Context and State Dependency: Memories are more easily retrieved in similar contexts or emotional states as when formed.

Recall & Recognition

• Recall: Retrieving information without cues (e.g., short answer).

  • Tip-of-the-Tongue Phenomenon: A near-recall situation where the answer seems close.

• Recognition: Identifying previously learned materials (e.g., multiple choice).

  • False Positives: Incorrect recognition due to confusion.

• Serial Position Effect: Likelihood of remembering items based on their position in a sequence.

  • Primacy Effect: Remembering earlier items more.

  • Recency Effect: Remembering the most recent items more.

Automatic Encoding

• Definition: Certain memories enter long-term memory effortlessly.

• Flashbulb Memories: Vivid memories of emotional events, enhanced by emotional associations.

Constructive Processing of Memories

• Constructive Processes: Altering memories during retrieval based on new experiences or information.

  • Hindsight Bias: Belief that one could have predicted an outcome due to memory alterations.

  • Misinformation Effect: Misleading post-event information alters memory.

  • False Memory Syndrome: The creation of false memories through suggestions.

Forgetting

• Curve of Forgetting: Pattern showing rapid forgetting within the first hour.

• Encoding Failure: Inability to process information into memory.

• Interference:

  • Proactive Interference: Older memories interfere with new.

  • Retroactive Interference: Newer information obstructs recall of old information.

Neuroscience of Memory

• Key Structures:

  • Cerebellum: Stores procedural memories.

  • Hippocampus: Crucial in forming new declarative long-term memories.

  • Frontal and Temporal Lobes: Involved in short and long-term memory.

Summary of Memory Disorders

• Infantile Amnesia: Inability to recall events from before age 3.

• Neurocognitive Disorder: Cognitive decline affecting memory.