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Model of Memory
Turning now to Long-Term Memory
Sensory Signals
Sensory Memory
Short-Term Memory
Long-Term Memory
ATTENTION
REHEARSAL
RETRIEVAL
Some Distinctions in LTM
• Endel Tulving: There are two broad categories of information that are represented in LTM -
• Episodic Memory: memory of an event in your life
• autobiographical• has a temporal context - something about time is
encoded along with the memory
Some Distinctions in LTM
• Endel Tulving: There are two broad categories of information that are represented in LTM -
• Semantic Memory: memory of facts, knowledge of the world
• unconnected to an autobiographical event• no temporal context
Some Distinctions in LTM
• Procedural Memory: memory for actions
Long-Term Memory
• Capacity is huge (unlimited?)
Long-Term Memory
• Structure of encoding is associative
When You Don’t Remember
• Two reasons why you don’t remember:
When You Don’t Remember
• Two reasons why you don’t remember:
• Unavailable– It wasn’t successfully encoded - something went wrong while
you were studying
When You Don’t Remember
• Two reasons why you don’t remember:• Unavailable
– It wasn’t successfully encoded - something went wrong while you were studying
• Inaccessible– memory is stored but cannot be retrieved, perhaps because appropriate connections aren’t being
made
Implicit vs. Explicit Memory
• Implicit Memories are ones that are encoded and present, but are not consciously accessible
• Explicit Memories are memories to which you have conscious access
Amnesia
• Loss of memory ability - usually due to lesion or surgical removal of various parts of the brain
Causes of Amnesia• Concussion• Migraines• Hypoglycemia• Epilepsy• Electroconvulsive shock therapy• Specific brain lesions (i.e. surgical removal) • Ischemic events• Drugs (esp. anesthetics)• Infection• Psychological• Nutritional deficiency• Lack of Sleep!
Amnesia
• Loss of memory ability - usually due to lesion or surgical removal of various parts of the brain
• Two broad categories:– Retrograde: loss of memories for events
prior to damage
Amnesia
• Loss of memory ability - usually due to lesion or surgical removal of various parts of the brain
• Two broad categories:– Retrograde: loss of memories for events
prior to damage– Anterograde: loss of ability to store new
memories of events after damage
RetrogradeAmnesia
AnterogradeAmnesia
Amnesia
Amnesia
• Short-term and sensory memory are typically functional
Korsakoff’s Syndrome
The Lost Mariner - What happened to Jimmie? What was his life like?
Korsakoff’s Syndrome (The Lost Mariner)
• Lesions to Medial Thalamus– Results from chronic alcoholism and
consequent thiamine deficiency
Korsakoff’s Syndrome (The Lost Mariner)
• Lesions to Medial Thalamus– Results from chronic alcoholism and
consequent thiamine deficiency– Severe anterograde amnesia
Korsakoff’s Syndrome (The Lost Mariner)
• Lesions to Medial Thalamus– Results from chronic alcoholism and
consequent thiamine deficiency– Severe anterograde amnesia– Severe retrograde amnesia extending
years before damage
Korsakoff’s Syndrome (The Lost Mariner)
• Lesions to Medial Thalamus– Results from chronic alcoholism and
consequent thiamine deficiency– Severe anterograde amnesia– Severe retrograde amnesia extending
years before damage– Confabulation - make up stories to explain
absence of memory
Korsakoff’s Syndrome (The Lost Mariner)
• Lesions to Medial Thalamus– Results from chronic alcoholism and
consequent thiamine deficiency– Severe anterograde amnesia– Severe retrograde amnesia extending years
before damage– Confabulation - make up stories to explain
absence of memory– Often unaware of their deficit
H. M.
• Patient H. M. - suffered from extreme epilepsy
H. M.
• Patient H. M. - bilateral resection of medial temporal lobes (containing hippocampus)– William Beecher Scoville and Brenda
Milner - late 1950’s
H. M.
• Patient H. M. - bilateral resection of medial temporal lobes (containing hippocampus)– William Beecher Scoville and Brenda
Milner - late 1950’s – Severe anterograde amnesia
H. M.
• Patient H. M. - bilateral resection of medial temporal lobes (containing hippocampus)– William Beecher Scoville and Brenda
Milner - late 1950’s – Severe anterograde amnesia– Retrograde amnesia for 1 - 3 years before
surgery
H. M.
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H. M.
• Some aspects of memory were spared (at least to some extent)
H. M.
• Some aspects of memory were spared (at least to some extent)– Procedural memory was largely unaffected
- amnesia was largely restricted to episodic memory
H. M.
• Some aspects of memory were spared (at least to some extent)– Procedural memory was largely unaffected
- amnesia was largely restricted to episodic memory
– Some implicit awareness of recent events
H. M.
• Some aspects of memory were spared (at least to some extent)– Procedural memory was largely unaffected
- amnesia was largely restricted to episodic memory
– Some implicit awareness of recent events– Normal digit span (short-term memory) !
Hypermnesia - S.
• “Photographic” extreme memory ability (a mnemonist)
Hypermnesia - S.
• “Photographic” extreme memory ability (a mnemonist)
• Able to recall complex test stimuli
Hypermnesia - S.
• S. used two “strategies” or abilities typical of mnemonists:– Rich synesthesia-like quality to his
perception of stimuli - leads to stronger associative links
Hypermnesia - S.
• S. used two “strategies” or abilities typical of mnemonists:– Rich synesthesia-like quality to his
perception of stimuli - leads to stronger associative links
– Vivid and elaborate mental imagery of things he should remember
Hypermnesia - S.
• “ Even numbers remind me of images. Take the number 1. This is a proud, well-built man; 2 is a high-spirited woman; 3 a gloomy person (shy, I don’t Know); 6 a man with a swollen foot...”
Luria, A.R. The mind of a mnemonist. 1968
Luria, A.R. The man with a shattered world. 1972
Next Time
Recall and false memories - Loftus