Ch 6 Flashcards
The Serial Position Curve
The 16 items were presented one-at-a-time, in a series
- Serial position- where an item was in the list (e.g., 1st, 2nd, 3rd)
Did we recall things equally across the whole list?
Primacy
The first few words get more rehearsal time for encoding into LTM
Recency
The last few words or items are well remembered because they are still in the STM/WM loop
Memory Rehearsal
Allows transfer from WM to LTM
Anterograde Amensia
- Impaired ability to remember new information after trauma
Retrograde Amnesia
- Loss of old memories before the traumatic incident
- Usually graded
Henry Molaison (H.M.) Feb 26, 1926 - Dec 2, 2008
History:
- Epilepsy (seizures) started at age 10 due to getting hit by a bicycle
Surgery in 1953:
- bilateral temporal lobe resection
- Destroyed 2/3 of hippocampus, part of amygdala
Results:
- seizures improved
- IQ normal
- STM/WM intact: could hold a conversation, and had normal digit scan
- LTM severe deficits
- retrograde amnesia for 3 years before surgery could remember childhood
- anterograde amnesia: couldn’t form any new LTM
- He remained largely the same person with otherwise normal cognitive abilities
Double Dissaccoiation
When two related mental processes are shown to function independently from each other
Clive Wearing
- British musical conductor
- hippocampus partly destroyed by a viral infection of his brain fluid
- STM/WM still interact
- Could not form any new LTM
- One of the most severe cases of anterograde amnesia
- But does remember his wife
- Doesn’t remember he just saw her a few minutes ago
- Diary, every moment is new
- As for his retrograde amnesia, he could remember facts like Deborah was his wife
- Could not remember episodes though like him dating Deborah
What is it like to have anterograde amnesia?
Everyday moment is like waking from a long dream
Impaired STM/WM but intact LTM (placeholder)
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Patient KF
- Traumatic brain injury though motorcycle accident
- Impaired STM/WM
- digit span = 2
- couldn’t repeat words
- very limited recency effect (serial position curve): just 1 item instead of normal 5-6 items
- Intact LTM
- Could learn word pairs, word lists, new episodic memories of life
Anatomy of a Long Term Memory Experiment
Study phase (encoding) -> Distractor Phase (retention interval) -> Test Phase (retrieval)
Can you retrieve things if you do not rehearse (encode) them?
No, you cannot retrieve what was never encoded
The Two Types of Long-Term Memory
Explicit and Implicit
Explicit Memory
Memory that can be consciously recalled/retrieved. It’s conscious and deliberate
Ex: Memory I the form of person events or general knowledge
Implicit Memory
A change in behavior resulting from prior information/experience but without you consciously retrieving that information
Explicit Memory’s Two types of information
Episodic and Semantic
Episodic Long Term Memory
Memory of a specific experience/episode in the past
Ex: Think about what you ate for lunch yesterday
Semantic Longer Term Memory
Memory for generalized knowledge
Ex: Is a robin a bird?
Is a Suv a card?
Don’t remember when or how you know the information but you know it
Implicit Memory
- Classical Conditioning
- Procedural Memory
- Priming
Kent Cochran
- Another motorcycle accident victim at the age of 30
Anterograde amnesia- Can’t form new LTM
Retrograde amnesia-
- He could remember facts
Ex: facts about bowling, childhood address, cars, stalactites vs. stalagmites
- Could not remember episodes like the time when his whole neighborhood was evacuated due to a chemical train spell
Patient MN
Japanese Woman Brain tumor in her 50’s
Anterograde amnesia- could not form any new LTM
Retrograde amnesia- Couldn’t remember facts
- Could not draw a map of Japan
- Couldn’t remember public events Like the Tokyo Olympics, the death of the emperor, the Korean War
- Couldn’t remember technical terms from her banking profession
- Did not recognize very famous cultural items
Could remember episodes
- boyfriends, school excursions, drama performances, finding a job, participation in the broadcasting club, and taking a leave of absence from school due to disease
Patient LP
Italian woman, viral damage at age 40
- Anterograde amnesia was not terrible could learn some new personal episodes
Could not remember facts
- Beethoven, Italty in WW2, Hitler
Can remember episodes
- engagement, wedding, honeymoon, children, holidays
Procedural Memory
- Long-term memory for the skills involved in particular tasks
- Demonstrated by skilled performance, and is often separate from the ability to verbalize this knowledge (non-declarative)
- Not necessarily tied to a specific memory of where/when learned like episodic
- Not necessarily conscious of how we’re doing it
Procedural Memory Tasks
Cohen & Squire, 1980
- Korsakoff patients: alcoholic for many years
- Vitamin B1 deficiency (from poor diet) -> brain damage, anterograde amnesia
- no explicit memory of ever having done the task, yet performance was still better over time!
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Back to Patient HM
Did a mirror tracing test in which his performance got better and better across three days
- HM and other amnesiacs demonstrated the ability for amnesiacs to learn in procedural memory tasks
Dissociation of Explicit and Implicit
Humans with amnesia generally have intact procedural memory
- Korsakoff patients
– Could not store new explicit memories in LTM
– Could get better at backward reading
- HM
– Could not store new explicit memories in LTM
– Could improve at a mirror drawing task over time (Implicit)
- Clive Wearing
– Could not store new explicit memories in LTM
– Could learn to play new piano pieces and get better at it (Implicit)
Priming
Humans with amnesia generally have intact priming memory (Graf et al., 1985)
- Explicit Task- Recall words that were previously seen
- Implicit Task- Complete fragments of words previously seen
Claparede the Swiss neurologist
Worked with an anterograde amnesic patient who never remembered him
- Pricked her hand when introducing himself one day
- The patient refused to shake his hand the next times for introductions even though she did not remember Claparede from previous encounters
Ken Cochrane
- severe retrograde episodic amnesia also couldn’t imagine the future
- The same brain areas used for episodic recall (thinking of past events) are also used for imagining future events!
– in both cases, your brain is simulating… the past or the future!
Where is memory in the brain?
Working memory: the mostly pre-frontal cortex
Long Term memory: likely distributed across the whole cortex
What about the hippocampus?
- People with lesions to their hippocampus (H.M., Clive W.) struggle to make new long-term memories
- Probably involved with both LTM and WM
What about semantic vs episodic?
- Double dissociation suggests separate locations
- Brain imaging studies suggest some overlap in regions and some differences (Levine et al., 2004)
How LTM memory is stored in the cerebral cortex
The formation of engram [memory] involves strengthening of synaptic connections between populations of neurons that are active during an event… This increases the likelihood that the same (or similar) activity pattern within this cell assembly can be recreated at a later time
Interplay of Semantic & Episodic Memory
Most things start out as semantic and episodic
- lose episodic over time
- keep semantic
Repisodes
Repeated episodes get kinda merged into a generalized representation over time
Semantic memory is enhanced when connected to episodic
- Recall for names of public figures is better when associated with personal experiences
Semantic memory influences episodic memory thru the direction of attention
- Knowledge about a situation influences what we remember
Autobiographical memory utilizes both types
How does time affect memories?
Forgetting increases with longer intervals after encoding
Forgetting is not an “all-or-nothing” process
- Familiarity: semantic memory
- Recollection: episodic memory
Remember/Know the procedure
- Semanticization of remote memories
– Loss of episodic details for memories of long-ago events
Priming
Presentation of priming stimulus changes a person’s response to a test stimulus
Repetition priming
- Test stimulus the same or similar to the priming stimulus
- Called implicit memory; person may or may not remember original presentation of priming stimuli
Priming in Everyday Experience
Perfect and Askew (1994)
- Propaganda effect: more likely to rate statements read or heard before as being true
- Involves implicit memory because it can occur when people are not aware of previously seeing or hearing statement
- Implications for advertisements
Classical Conditioning and Implicit Memory
- Pairing a neutral stimulus with a reflexive response
- Involves implicit memory when person has forgotten about original paring of the stimulus and the response
