Transcript Chapter 6

Chapter 6
Long-Term Memory: Structure
Some Questions to Consider
• How does damage to the brain affect the
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ability to remember what has happened in the
past and the ability to form new memories of
ongoing experiences?
How are memories of personal experiences,
like what you did last summer, different from
memories for facts, like state capitols?
How do the different types of memory interact
in our everyday experience?
How has memory loss been depicted in
popular films?
Long-Term Memory
• “Archive” of information about past events
and knowledge learned
• Works closely with working memory
Long-Term Memory
• Storage stretches from a few moments ago to
as far back as one can remember
• More recent memories are more detailed
Long-Term Memory
• Korsakoff’s syndrome
– Result of chronic alcoholism
– Unable to form new long-term memories
– Anterograde amnesia
Double Dissociation
• Functioning STM but cannot form new LTM’s
– Clive Wearing
– H.M.
• Poor STM but functioning LTM
– K.F.
Caption: A double dissociation for STM and LTM
Serial Position
• Murdoch (1962)
• Read stimulus list, write down all words
remembered
Serial Position Curve
• Memory better for stimuli presented at
beginning
– Primacy effect
– More time to rehearse, more likely to enter
LTM
Serial Position Curve
• Memory better for stimuli presented at end of
list
– Recency effect
– Stimuli still in STM
Caption: Serial position curve (Murdoch, 1962). Notice that memory is
better for words presented at the beginning of the list (primacy
effect) and at the end (recency effect).
Coding in Long-Term Memory
• Predominant type: semantic coding
– Remember meaning, not exact wording
• Others: auditory, visual
Types of Long-Term Memory
• Implicit/non-declarative: unconscious memory
– Procedural
– Priming: previous experience changes response without
conscious awareness
• Explicit/declarative: unconscious memory
– Episodic: personal events/episodes
– Semantic: facts, knowledge
Caption: Long-term memory can be divided into declarative memory
and implicit memory. We can also distinguish between two types of
declarative memory, episodic and semantic. There are a number of
different types of implicit memory. Two of the main types are repetition
priming and procedural memory.
Types of Long-Term Memory
• Declarative: conscious recollection of events
experienced and facts learned
– Episodic: memory for personal events
– Semantic: facts and knowledge
Types of Long-Term Memory
• Episodic involves mental time travel
– No guarantee of accuracy
• Semantic does not involve mental time travel
– General knowledge
• Episodic and semantic show a double
dissociation
Separation of Episodic and Semantic Memories
• K.C. damaged hippocampus
– No episodic memory, cannot relive any
events of his past
– Semantic memory intact, can remember
general information about the past
Separation of Episodic and Semantic Memories
• Italian woman
– Impaired semantic memory
– Episodic memory for past events was
preserved
Separation of Episodic and Semantic Memories
• Evidence from brain-imaging experiments
that retrieving episodic and semantic
memories activate different areas of the brain
Episodic and Semantic Memories
• 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
– Personal semantic memory: semantic
memories that have personal significance
– Can influence what we experience
(episodic) by determining what we attend
to
Types of Long-Term Memory
• Implicit: memory that unconsciously
influences behavior
– Repetition priming
– Procedural memory
– Classical conditioning
Repetition Priming
• Presentation of one stimulus affects
performance on that stimulus when it is
presented again
Repetition Priming
• Tulving (1982)
– Presented words and then fragments to be
completed
– Participants completed many more primed
words than new words
Implicit Memory
• Warrington and Weiskrantz (1968)
– Korsakoff’s syndrome patients
– Showed fragmented pictures, participant
had to identify
Caption: Incomplete pictures developed by Gollin (1960) that were used by Warrington
and Weiskrantz (1968) to study implicit memory in patients with amnesia. (Reprinted
from Nature, London, 217, March 9, 1968, E. K. Warrington, & L. Weiskrantz, “New
Method of Testing Long-Term Retention With Special Reference to Amnesic Patients,”
pp. 972-974, Fig. 1. Copyright © 1968 with permission from Nature Publishing Group.
Caption: Results of Warrington and Weiskrantz’s (1968) experiment.
Implicit Memory in Everyday Experience
• Perfect and Askew (1994)
– Propaganda effect: more likely to rate
statements read or heard before as being
true
• Implications for advertisements
Implicit Memory: Procedural Memory
• Skill memory: 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.)
Implicit Memory: Classical Conditioning
• Pairing a neutral stimulus with a reflexive
response