BHS Memory and Amnesia History of Memory Research and Early Memory Models

Three Definitions of Memory The location where memory is stored. The physical entity that holds the memory: Trace Engram The processes used to acquire (learn), store (encode) or retrieve information.

Metaphors for Memory 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. Memory is NOT like a muscle – more like a key.

Metaphors 1 Recorder of experience Wax tablet Record player Writing pad Tape recorder Video camera Organized storage House Library Dictionary

Metaphors 2 Interconnections Switchboard Network Jumbled Storage Birds in an aviary Purse Junk drawer Garbage can

Metaphors 3 Temporal Availability Conveyor belt Content Addressability Lock and key Tuning fork Forgetting of Details Leaky bucket Cow’s stomach Acid bath

Metaphors 4 Reconstruction Rebuilding a dinosaur Active processing Workbench Computer program

The Ancients Plato (428?-347? B.C.) Rationalist Dualist – mind and body are distinct Wax tablet metaphor (can be erased, the better the impression the more readable. Aristotle ( B.C.) Empiricist Laws of association Similarity Contrast Contiguity

Modern Precursors St. Augustine ( ) Advanced description of memory in the Confessions similar to modern views. Robert Hooke ( ) Modern insights into memory, but were ignored when he was overshadowed by Newton. Darwin and natural selection ( ) Organism changes to exploit the environment Memory has developed to perform specific tasks.

Philosophy of Mind Empiricists – extended Aristotle’s ideas Berkeley, Locke, Mill, Hume Knowledge through observation Associationism Rationalists – antagonists to empiricists Descartes, Kant Active involvement of the mind building ideas Knowledge through theories (e.g., schemas)

Early Researchers Ebbinghaus ( ) 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 ( ) How does prior knowledge influence memory Reconstruction is guided by schemas (concepts)

Gestalt Psychology 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 elements and context. Isomorphism of mental representation

Behaviorism 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). Classical and operant conditioning both involve memory.

Verbal Learning A behaviorist approach to the learning of verbal materials. Developed from Ebbinghaus’s work. Memorization is the “attachment of responses to stimuli” Forgetting is the “loss of response availability”

Paired Associates Paradigm Paired associate learning – people memorize pairs of items (BIRD-GLOVE): A-B -- the first item is the cue and the second 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 Lashley ( ) 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 Hebb -- The Organization of Behavior (1949) Forerunner of computational neuroscience 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 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 George Miller The Magical Number Seven, Plus or Minus 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 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 Memory is not unitary but consists of several subcomponents (parts). Tulving’s Triarchic Theory: EpisodicAutonoetic (self) SemanticNoetic (formal knowledge) ProceduralAnoetic (automatic skills)

Other Classifications Declarative vs Nondeclarative Declarative includes episodic and semantic memory Nondeclarative includes procedural memory, classical conditioning and priming Explicit vs implicit Explicit memory involves consciousness, implicit does not.

Current Issues 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