Targeted Memory Reactivation: Enhances memory consolidation during sleep.
Storage
Definition: The retention of memory over time; the third stage of long-term memory.
Hierarchies: Organizing pieces of information from specific to general. For example:
Human, hominid, primate, mammal, animal.
Associative Networks: A chain of associations linking related concepts where each concept is a node.
Examples: "Fire engine" forms a rich network of related concepts (Collins & Loftus, 1975).
Retrieval
Definition: The recovery of information stored in memory; the fourth stage of long-term memory.
Retrieval Ease: Depends on encoding, consolidation, and storage stages.
Some memories need conscious effort to retrieve.
Aids to Memory Formation
Attention:
Essential for memory formation; deeply processing information aids recall.
Levels of Processing: The deeper the encoding, the better the recall.
Effects on Recall:
Research shows the more deeply one processes information, the better the recall performance.
Example: Presentation of a word list twice improves depth of processing effects on recall (Craik & Lockhart, 1972).
Sleep Benefits:
Sleep protects memory from being forgotten, making it more retrievable.
Retention improves when sleep occurs shortly after learning.
Emotional Impact:
Emotions enhance both encoding and retrieval processes.
Flashbulb Memory: A detailed snapshot of a major emotional event, recalling specific actions at that time.
Impediments to Memory Formation
Distraction's Impact: Distractions lead to poor memory formation.
Divided Attention: Trying to focus on multiple tasks negatively affects memory.
Emotional Memories: While emotions can strengthen recall, they can also distort memories.
Emotional memories may be held with high confidence but can be significantly inaccurate.
Autobiographical Recall Bias: A tendency to recall personal events more positively.
Types of Memory
Brenda Milner and "H. M." Case Study
H. M. lost the ability to form new memories after having his hippocampus removed but could improve skills (e.g., star-tracing task) over time (Kandel, 2006; Kandel, Kupferman, & Iversen, 2000).
Three Major Types of Memory
Three-Stage Model of Memory:
Sensory Memory:
Holds information in its original form for about half a second or less.
Short-Term Memory:
Temporarily stores a limited amount of information (2-30 seconds) before it’s forgotten or stored.
Chunking: Organizing items into smaller, meaningful units to improve memory retention.
Serial Position Effect: Better recall of items at the beginning (primacy) and end (recency) of a list; recency effects diminish with distractions.
Long-Term Memory:
Capable of storing vast amounts of information from 30 seconds to a lifetime.
Two categories:
Implicit Memory (Non-declarative): Knowledge gained through experience, such as skills.
Types include:
Procedural Memory: Skills and learned behaviors.
Priming: Improved recall due to earlier exposure to similar stimuli.
Explicit Memory (Declarative): Conscious recollection of facts and events.
Types include:
Semantic Memory: General knowledge and facts learned.
Episodic Memory: Recollection of personal experiences and events.
Highly Superior Autobiographical Memory (HSAM): Exceptional recall of personal events, often correlating with obsessive-compulsive behavior.
Memory and the Brain
Neuroplasticity and Memory
Engram:
A lasting physical change in the brain created from experience that becomes a specific memory.
Long-Term Potentiation (LTP):
Proposed by Donald Hebb; refers to the strengthening of synaptic connections due to repetitive stimulation.
Principle: "Neurons that fire together, wire together."
Memory Formation:
Eric Kandel’s discovery with sea slugs emphasizes spaced repetition for transitioning from short-term to long-term memory, showing that environmental enrichment leads to neurological improvements.
Brain Regions Involved in Memory
Prefrontal Cortex:
Involved in attention, social behavior, impulse control, and working memory.
Hippocampus:
Consolidates memories through rehearsal and repetition.
Implicit Memories: Stored across various brain areas including the striatum and amygdala (Kandel, 2006).
Malleability of Memory
Reconsolidation
Definition: Reactivation of a memory may weaken the original memory, leading to a new consolidation, thus altering the original memory.
Attention Types
Selective Attention: Memory relies on focused attention, which is inherently selective.
Divided Attention: Focusing on multiple tasks simultaneously decreases memory performance.
Suggestibility and Reliability
Suggestibility: Memories can be implanted by leading questions or comments.
False Memories & Misinformation Effect: Distorted memories may arise from inaccurate information being integrated as true.
Recovered Memories: Old memories that have lain dormant can be reactivated.
Forgetting and Memory Loss
Forms of Forgetting
Interference: Competing information disrupts recall.
Retroactive Interference: New experiences impede retrieval of old information.
Proactive Interference: Old memories interfere with learning new information.
Forgetting Curve: Depicts how recall typically declines over time.
Absent-Mindedness: Memory lapse due to lack of attention, worsened by age.
Blocking: Inability to retrieve information previously encoded.
Repression: Active inhibition of stored memories.
Memory Loss Due to Brain Injury and Disease
Amnesia: Memory loss resulting from brain injury or illness.
Anterograde Amnesia: Inability to remember events after injury.
Retrograde Amnesia: Inability to recall events prior to injury.
Dementia: Severe memory loss including declines in working memory and prospective memory, especially noted during the COVID-19 pandemic.
Bringing It All Together
Cultural Perspectives on Memory Systems
Different cultures emphasize varying memory systems influenced by:
Coping styles, perceptual differences, brain formation influences, racial biases, and health levels affecting dementia rates.
Chapter Review
Summary of key concepts and the connections between memory phases, types, and their neurological basis, highlighting both individual and cultural differences in memory formation and its malleability.