Chapter 6-Long Term Memory: Structure Flashcards
Long term memory
- archive of information about past events and knowledge learned
- works closely with working memory
- storage stretches from a few moments ago to as far back as one can remember
- more recent memories are more detailed
Serial Position
Murdoch-studied the distinction between STM and LTM using a serial position curve
Participants had to read a stimulus list and write down all words remembered
Difference between serial position and memory span
Number of items for serial process is bigger than memory span (20 items or more)
When you report items you can report them in your own sequence (Free recall)
Serial process results
Last few items were recalled the best (recency effect) and first few items second best (primacy effect) and middle items worst
Primacy effect in serial position
Memory better for stimuli presented at beginning
More time to rehearse, more likely to enter LTM
The slower the pace in presenting the list, the bigger the primacy effect
Recency effect
Memory better for stimuli presented at end of list
Stimuli in STM
So if some delay between the test and the study, the recency effect will be eliminated
Flanker and Cunitz experiment
Slowed down time in presentation of list
Allows for more rehearsal so greater primacy effect observed
No effect on recency effect
Rundus’s experiment
Asked participants to repeat aloud during the interval between two items (1 word every 5 seconds)
Resulted in more rehearsing and therefore greater primacy effect
30 second delay after presenting a list of items in a serial position
Eliminates the recency effect but primacy effect still there
Wickens et al. Proactive interference experiment
Semantic encoding in short and long term memory
- Had four trials of fruit groups that had three fruits in each trial
- after each trial subjects counted backwards for 15 seconds and then recalled the names of the fruits
- Had a professional group where last trial was fruit
- they also counted back 15 seconds then recalled names
Results of Wickens Proactive Interference Experiment
The fruit groups showed reduced performance on trials 2,3, and 4 caused by proactive interference
The professions group showed reduced performance on trials 2 and 3 but increase in performance on trial 4 which represents a release from proactive interference because the names of fruit were presented
Semantic encoding in long term memory
Based on meaning
Recognition memory: identification of a previously encountered stimulus
Sachs: participants chose the sentences that were similar in meaning but not exactly the same
HM and Clive Wearing
Surgery removed hippocampus / damage to hippocampus
Retained STM (can do memory span) but unable to transfer info to LTM
Unable to form new LTM
KF
Accident damaged parietal lobe
Impaired STM (reduced digit span ~2) but functional LTM
Able to form and hold new memories
Hippocampus also holds __________
New information
E.g. experiment that measured hippocampus fMRI responses. Found that responses increases during delay for novel faces but only increases slightly for faces people had seen before
Implicit/non-declarative LTM
Unconscious memory
Procedural (skill), priming, conditioning
Priming: previous experience changes response without conscious awareness
Explicit/declarative LTM
Conscious memory of events experienced and facts learned
Episodic: memory for personal events
Semantic: facts, knowledge
Episodic memory
- explicit LTM
- involves mental time travel
- tied to personal experience; remembering is reliving
- “self-knowing”
Semantic memory
- explicit LTM
- knowledge, facts
- “knowing”
Separation of Episodic and Semantic Memories
K.C. Damaged his hippocampus
- no episodic memory (can not relive any past events)
- semantic memory intact (can remember general info about past)
Italian woman
- impaired semantic memory
- episodic memory for past events preserved
- couldn’t remember meanings of words or recognize familiar people but could remember what happened months before
Levine et al
Participants either listened to their own diaries or general knowledge
Evidence from fMRI showed that retrieving episodic and semantic memories activate different areas of the brain
Episodic can be lost, leaving only ______
Semantic
Acquiring knowledge may start as episodic but then fade to semantic
Semantic can be enhanced if ______
Associated with episodic
Autobiographical memory: memory of specific experiences from own life, includes semantic (facts related to these events) and episodic (relived specific events)
Personal semantic memory: semantic memories that have personal significance
Semantic knowledge can influence formation of ________
Episodic memory
Can influence what we experience (episodic) by determining what we attend to (football game)
The Effect of Time
Forgetting increases with longer intervals from the original encoding
- Remember/Know procedure
- Semanticization of remote memories (loss of episodic details for memories of long ago events)
Constructive episodic simulation hypothesis
Addis
- episodic memories are extracted and recombined to create simulations of future events
- helps us to anticipate future needs and guide future behaviours
- adaptive function similar to mind wandering
Procedural memory
Implicit LTM
- Memory for actions
- no memory of where or when learned
- perform procedures without being consciously aware of how to do them
- people who cannot form new LTMs can still learn new skills (e.g. H.M.)
Coglab: implicit learning
On each trial a dot appeared in one of four locations and you are asked to press one of four keys on the keyboard to indicate the dots location
Random condition: dots never followed a pattern
Pattern condition: dots followed a pattern on all blocks except for block 10
Coglab: implicit learning results
Mean RT decreases with each block for both conditions but the decrease is greater for the pattern condition except for on block 10-there should be a sudden increase because that block uses a different pattern
Destrebecqz and Cleeremans
- did similar experiment but with no RSI and an RSI (delay)
- no RSI is implicit knowledge (no time to think-slower time)
- RSI is explicit knowledge (time to think-faster response)
Review bar chart slide
Repetition priming
Presentation of one stimulus affects performance on that stimulus when it is presented again
-Graf and coworkers
-tested explicit memory (recall) and implicit memory (word completion)
Three groups:
1. Amnesia patients with Korsakoff’s syndrom
2. Patients without amnesia being treated for alcoholism
3. Patients without amnesia who had no history of alcoholism
Repetition priming results
For recall (explicit): INPT>ALC>AMN
For implicit: AMN>ALC>INPT
Propaganda effect
Perfect and Askew
- more likely to rate statements read or heard before as being true
- implications for advertisements
