Chapter 8: Memory Study Notes on Memory and Forgetting
Fundamental Functions of Memory
Memory Overview: Memory is the set of processes used to encode, store, and retrieve information over different periods of time.
Encoding: This is the initial process of memory. It involves the input of information into the memory system. This can occur in two primary ways:
Effortful Processing: Requires active attention and conscious effort. When learning a new skill, such as driving a car, you must put forth effort to encode information regarding how to start the car, how to brake, and how to negotiate turns.
Automatic Processing: Once a skill is mastered, additional information about that skill can be encoded automatically without conscious thought.
Storage: This function involves the retention of encoded information over time. Information must be kept in the memory system for future use.
Retrieval: The third function of memory, which involves getting information out of memory storage and back into conscious awareness.
Visual Triggers: Photographs are external tools that can trigger memories and bring past experiences back to life by providing cues for retrieval.
Atkinson-Shiffrin Model of Memory
Model Definition: According to the Atkinson-Shiffrin model, information must pass through three distinct stages to be stored in long-term memory:
Sensory Memory
Function: Temporary storage for raw sensory information.
Sensory Input: Visual and auditory stimuli.
Capacity: Large, but very short-lived.
Duration: Visual information (iconic memory) lasts a fraction of a second; auditory information (echoic memory) lasts approximately seconds.
Short-Term Memory (STM)
Function: A brief storage system for information currently being used or processed.
Capacity: Very limited, typically documented as items (a range of to items). This is based on research by Peterson & Peterson ().
Duration: Less than seconds without active rehearsal.
Displacement: Occurs when STM is full; a new incoming item pushes out an existing item, causing it to be forgotten.
Chunking: A strategy to increase the efficiency of STM by grouping or organizing bits of information into larger, manageable units (e.g., remembering a sequence like "F-B-I" rather than "F, B, I").
Rehearsal: The act of purposely repeating information to maintain it in short-term memory or to facilitate transfer to long-term memory.
Long-Term Memory (LTM)
Function: Permanent or relatively permanent storage of information.
Capacity: Virtually unlimited.
Duration: Can last from minutes to an entire lifetime.
Working Memory and Memory Strategies
Working Memory: A memory subsystem used when trying to understand information, use it to solve a problem, or communicate. It is the active "workspace" of the mind.
Memory Strategies:
Maintenance Rehearsal: Repeating information over and over to keep it in working memory.
Elaborative Rehearsal: Linking new information to existing knowledge to make it more meaningful and easier to transfer to LTM.
Components of Long-Term Memory
Explicit (Declarative) Memory: Memories that we consciously try to remember and recall.
Episodic Memory: Personal recollections of events as they have been subjectively experienced (e.g., a specific surfing trip).
Semantic Memory: General knowledge, objective facts, and information about the world (e.g., knowing that Honolulu is in Hawaii).
Implicit (Nondeclarative) Memory: Memories that are not part of our consciousness; they are demonstrated through performance.
Procedural Memory: Knowledge of how to perform motor skills (e.g., riding a bike, playing the piano).
Classically Conditioned Responses: Learned associations between stimuli that occur without conscious awareness.
Hyperthymesia: A rare condition known as super autobiographical memory. An example is the actress Marilu Henner, who can recall nearly every day of her life in vivid detail.
Measuring and Influencing Retrieval
Methods of Measuring Retrieval:
Recall: Producing required information by searching memory without external hints (e.g., an essay test).
Recognition: Identifying material as familiar or as having been encountered before (e.g., a multiple-choice test).
Relearning: Measuring retention as the percentage of time saved when material is learned a second time compared to the original learning time.
The Serial Position Effect: The tendency to recall the first and last items in a list better than the middle items.
The Context Effect: The tendency for information to be recalled better when the individual is in the same environment (context) where the information was first learned (based on Godden & Baddeley, ).
State-Dependent Memory Effect: The tendency to recall information better if the individual is in the same pharmacological or psychological state (e.g., mood or sobriety) as when the information was learned.
Biological Basis of Memory
Key Brain Structures:
Amygdala: Involved in the processing of fear and fear-related memories.
Hippocampus: Associated with declarative memory, episodic memory, and recognition memory.
Cerebellum: Plays a critical role in processing procedural memories, such as motor skills.
Prefrontal Cortex: Appears to be involved in remembering semantic tasks.
Neurochemistry:
Communication between neurons via neurotransmitters is essential for memory development.
Memory Consolidation: Repeated neuron activity leads to increased neurotransmitters in the synapse and stronger synaptic connections.
Involved Neurotransmitters: Epinephrine, Dopamine, Serotonin, Glutamate, and Acetylcholine.
Arousal Theory: Strong emotions trigger the formation of strong memories, while weaker emotional experiences produce weaker memories. Strong emotions release neurotransmitters that strengthen the memory trace.
Flashbulb Memory: An exceptionally clear and vivid recollection of an important, usually atypical, and emotional event (e.g., remembering exactly where you were during the terrorist attacks).
Amnesia
Definition: The loss of long-term memory resulting from disease, physical trauma, or psychological trauma.
Anterograde Amnesia: The inability to remember new information after the point of trauma. This is often caused by damage to the hippocampus, which prevents the transfer of information from STM to LTM.
Retrograde Amnesia: The loss of memory (partial or complete) for events that occurred prior to the traumatic event.
Memory as Reconstruction
Reconstruction: Memory is not a perfect recording; it is an account of an event pieced together from a few highlights. We often fill in gaps during retrieval.
Schemas: Mental frameworks of knowledge and assumptions about people, objects, and events that influence how we reconstruct memories.
Autobiographical Memory Bias: We often include recollections in our life stories that are subject to a positive bias (e.g., remembering a trip as the "best time of my life").
Expertise and Culture:
Expertise: Extensive background knowledge allows for more efficient reconstruction within a specific field.
Culture: Culturally based schemas influence what information is considered important to store and retrieve.
Eyewitness Testimony and False Memories
Innocence Project: Investigated cases where DNA evidence exonerated people; they found that eyewitness misidentification is the leading cause of wrongful convictions.
Elizabeth Loftus: A key researcher who argues that memory is highly subject to error and can be influenced by the misinformation effect.
Misinformation Effect: Exposure to incorrect information after an event can alter the memory of that event. Leading questions can change how a person remembers the severity or details of an accident.
Suggestibility: The quality of being inclined to accept and act on the suggestions of others, which can lead to false memories.
False Memory Syndrome: The recall of false autobiographical memories.
Repressed Memories: A controversial topic. Some psychologists believe traumatic childhood memories (like sexual abuse) can be repressed and later recovered through hypnosis. Loftus challenges this, suggesting that the techniques themselves (guided imagery, hypnosis) may create false memories through suggestibility.
Forgetting and Memory Errors
Reasons for Forgetting:
Encoding Failure: Information was never properly put into long-term memory (e.g., not being able to identify the correct details of a US nickel because we never focused on them).
Consolidation Failure: A disruption in the consolidation process, such as loss of consciousness from an accident, that prevents LTM from forming.
Interference: Retrieval failure caused by competing information.
Proactive Interference: Old information hinders the recall of new information.
Retroactive Interference: New information hinders the recall of old information.
Ebbinghaus and the Forgetting Curve: Hermann Ebbinghaus memorized lists of nonsense syllables (e.g., HEJ, TUQ, LEV) and found that forgetting is very rapid at first and then tapers off over time.
Schacter’s Seven Sins of Memory:
Transience: Accessibility of memory decreases over time (storage decay).
Absentmindedness: Lapses in attention causing forgetting.
Blocking: Temporary inability to access information (Tip-of-the-Tongue phenomenon; for example, forgetting a famous actor's name like Morgan Freeman).
Misattribution: Confusing the source of the memory.
Suggestibility: The creation of false memories due to outside influence.
Bias: Memories distorted by current belief systems.
Stereotypical Bias: Involves racial or gender biases (e.g., incorrectly associating African American names with basketball players).
Egocentric Bias: Enhancing memories to make ourselves look better.
Hindsight Bias: Maintaining that one knew an outcome was inevitable after it occurred ("I knew it all along").
Persistence: The inability to forget undesirable or traumatic memories, such as those experienced by veterans.
Strategies for Effective Studying
Elaborative Rehearsal: Link new info to other memories to make it more meaningful.
Self-Reference Effect: Make the info personally meaningful to oneself.
Overcome the Forgetting Curve: Keep studying and reviewing over time to prevent decay.
Rehearse: Engage in repeated practice.
Minimize Interference: Study in a quiet environment without distractions.
Aerobic Exercise: Promotes neurogenesis (growth of new brain cells in the hippocampus).
Sleep: Ensure adequate sleep for the brain to consolidate memories.
Mnemonic Devices: Use memory aids, such as the knuckle mnemonic to remember which months have days (represented by knuckles) versus those with fewer days (represented by the spaces between knuckles).