Transcript BHS 499-07 Memory and Amnesia

BHS 499-07
Memory and Amnesia
History of Memory
Research and Early
Memory Models
Three Definitions of Memory
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The location where memory is stored.
The physical entity that holds the
memory:
• Trace
• Engram
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The processes used to acquire (learn),
store (encode) or retrieve information.
Metaphors for Memory
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Metaphors are used because memory is hard
to understand and talk about.
Different metaphors capture different aspects
of memory.
The number of metaphors tells us about the
complexity of memory.
Some metaphors are better than others.
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Memory is NOT like a muscle – more like a key.
Metaphors 1
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Recorder of experience
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Wax tablet
Record player
Writing pad
Tape recorder
Video camera
Organized storage
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House
Library
Dictionary
Metaphors 2
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Interconnections
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Jumbled Storage
• Switchboard
• Network
• Birds in an aviary
• Purse
• Junk drawer
• Garbage can
Metaphors 3
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Temporal Availability
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Conveyor belt
Content Addressability
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Lock and key
Tuning fork
Forgetting of Details
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Leaky bucket
Cow’s stomach
Acid bath
Metaphors 4
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Reconstruction
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Active processing
• Rebuilding a dinosaur
• Workbench
• Computer program
The Ancients
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Plato (428?-347? B.C.)
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Rationalist
Dualist – mind and body are distinct
Wax tablet metaphor (can be erased, the better the
impression the more readable.
Aristotle (384-322 B.C.)
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Empiricist
Laws of association
• Similarity
• Contrast
• Contiguity
Modern Precursors
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St. Augustine (354-430)
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Advanced description of memory in the Confessions
similar to modern views.
Robert Hooke (1635-1703)
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Modern insights into memory, but were ignored when
he was overshadowed by Newton.
Darwin and natural selection (1809-1882)
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Organism changes to exploit the environment
Memory has developed to perform specific tasks.
Philosophy of Mind
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Empiricists – extended Aristotle’s ideas
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Rationalists – antagonists to empiricists
• Berkeley, Locke, Mill, Hume
• Knowledge through observation
• Associationism
• Descartes, Kant
• Active involvement of the mind building ideas
• Knowledge through theories (e.g., schemas)
Early Researchers
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Ebbinghaus (1850-1909)
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Nonsense syllables
• PIM
DAG ZOL CEK
Learning curve – massed vs spaced practice
Forgetting curve – forgetting occurs rapidly
Overlearning – studying after something is learned
Savings – decreased effort needed to relearn
Bartlett (1886-1969)
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How does prior knowledge influence memory
Reconstruction is guided by schemas (concepts)
Gestalt Psychology
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Gestalt movement
• Kohler, Koffka, Wertheimer
• The whole is different that the sum of its parts.
• Anti-reductionistic
• But did acknowledge the importance of
understanding the components of thought.
• Memory influenced by the configuration of
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elements and context.
Isomorphism of mental representation
Behaviorism
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Behaviorism (Pavlov, Thorndike)
• Psychology should be the study of observable
behavior.
• Reacting against introspection
• Associated with the term “learning”.
• Later behaviorists (like Tolman) used mental
explanations and representations (maps).
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Classical and operant conditioning both
involve memory.
Verbal Learning
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A behaviorist approach to the learning of
verbal materials.
• Developed from Ebbinghaus’s work.
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Memorization is the “attachment of
responses to stimuli”
Forgetting is the “loss of response
availability”
Paired Associates Paradigm
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Paired associate learning – people
memorize pairs of items (BIRD-GLOVE):
• A-B -- the first item is the cue and the second
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is the response
A-B C-D paradigm (two lists are learned)
A-B A-D paradigm (two associations learned)
A-B A-B’ paradigm (synonyms)
A-B A-Br paradigm (recombinations – hard!)
Early Neuroscience -- Lashley
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Lashley (1890-1958)
Search for the engram
Rats learned a maze.
Lashley progressively removed larger
and larger portions of rats brains, from
different locations.
Memory affected more by the amount of
brain tissue removed, not the location.
Hebb
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Hebb -- The Organization of Behavior (1949)
Forerunner of computational neuroscience
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Mathematical modeling of brain activity
What fires together, wires together
Signal reverberation within collections of cell
assemblies followed by a change in neural
interconnections
The Cognitive Revolution
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Thought is a valid subject for study
This is the field of psychology associated
with the term “memory”
Adopted the methodological rigor of the
behaviorists
The computer metaphor
• hardware vs. software
Miller’s Magic Number
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George Miller
• The Magical Number Seven, Plus or Minus
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Two (1956) – describes the capacity of short
term memory
Different for verbal items and digits
Limited capacity of memory
Organization aids memory (chunking)
The Modal Model of Memory
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Modal refers to sensory modality (way of
receiving info from outside world).
Heuristic means “rule of thumb” – this is
a way of thinking about memory but not
to be taken literally.
The guiding framework for decades.
Multiple Memory Systems
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Memory is not unitary but consists of
several subcomponents (parts).
Tulving’s Triarchic Theory:
• Episodic
• Semantic
• Procedural
Autonoetic (self)
Noetic (formal knowledge)
Anoetic (automatic skills)
Other Classifications
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Declarative vs Nondeclarative
• Declarative includes episodic and semantic
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memory
Nondeclarative includes procedural memory,
classical conditioning and priming
Explicit vs implicit
• Explicit memory involves consciousness,
implicit does not.
Current Issues
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Neurological bases for memory
Impact and importance of emotion on
memory
Use of multiple memory sources (fuzzy
trace theories)
Embodied cognition – how our grounding
in the world influences memory