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Memory:Schema Theory, A European Solution, Generalization hierarchies

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Cognitive Psychology ­ PSY 504
VU
Lesson 36
Memory
Representation of knowledge (Continued)
Schema Theory
Schema:
Schema is a Greek word which means frame.
A general knowledge structure that provides a framework for organizing clusters of knowledge.
When representing the knowledge we have about various categories, it is useful to be able to
encode the information that certain features are typical of a category while others are not.
Schemas are organized sets of facts. Subjects use schemas to infer that certain unobserved and
unmentioned elements must be present. It seems that schemas are a major mechanism for
elaborating material during study, and are also the major mechanism for reconstructing memories
at test.
Schema Theory refers to a collection of models presuming that we encode such knowledge
clusters into memory and use them to comprehend and store our experiences.
A European Solution
While Psychologists in US were busy developing Stimulus-Response Theories, Bartlett in
England and Piaget in Switzerland were arguing that behavior is influenced by large units of
knowledge organized into schemas.
Bartlett's Schema Theory
Bartlett (1932) conducted an experiment for getting evidence for the role of schemas in memory.
He used a story called "The War of the Ghosts". It has been used in research on many
subsequent occasions and is still a popular research item today. Bartlett was interested in how
the subjects would remember a story that fit in so poorly with their cultural schemas. He had
subjects recall the story after various delays. Bartlett's subjects showed clear distortions in their
memory for the story and these distortions appeared to grow with time.
Subjects were distorting the story to fit with their own cultural stereotypes. So he found when
subjects read a story that does not fit with their own schemas, they will exhibit a powerful
tendency to distort the story to make it fit.
According to the Bartlett, Schema is an active organization of past experiences in which the mind
abstracts a general cognitive structure to represent many particular instances of those
experiences. It means all past experience are organized actively in mind. Then we absorb new
experiences in our schemas.
A schema provides a knowledge structure for interpreting and encoding aspects of a particular
experience. At his time, Bartlett was not taken seriously.
The Rise of Schema Theory
In 1975 a number of prominent scientists argued that schemata/schemas are needed to organize
knowledge in artificial intelligence, cognitive psychology, linguistics, and motor performance. A
number of psychologists from different fields gave importance on schemas. Artificial intelligence
focused on schemas because schemas make knowledge that helps the computer in information.
Knowledge structures include all parts of information, for example a bird; it includes beak, flying
quality, legs, hair etc. Linguistic psychologist also gave importance to the schemas because
schemas help in organizing the linguistic knowledge.
Cognitive psychology was working on atomistic little bit idea at that time then they realized the
importance of schemas.
Bartlett's major assumptions were adopted and developed further into a modern schema theory.
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Cognitive Psychology ­ PSY 504
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Modern Schema Theory
Minsky (1975):
Minsky started the modern schemas theory again, for representing knowledge in Artificial
Intelligence Programs. He made many computer programs in which schemas were used. He said
mega knowledge structures are very important for computer programs.
Rumelhart (1980):
He said schemas are building blocks of cognition. Like atoms are building blocks of element.
Schema is very rich, brave and complex building block of memory.
Schemas provide skeleton structure to be filled out with detailed properties of a particular
instance. For example a bird schema of bird includes instances like feathers, beak, or other bird
features.
House: A Schema example
The basic insight is that concepts like house are defined by a configuration of features, and each
of these features involves specifying a value the object has on some attribute. The schema
representation is the way to capture this basic insight. Schemas represent the structure of an
object according to a slot structure, where slots specify values that the object has on various
attributes. So we have the following partial schema representation of a house:
For instance, our knowledge of what a house is like.
Slots are Values.
House
Superset schema: building a special slot in each schema is its superset schema. In
House, it is Building. Building has walls, roof, it is built on the ground etc
Parts: Rooms (living, bed, kitchen, etc.)
Materials: wood, bricks, stone, cement
Function: human dwelling
Shape: rectilinear, triangular
Size: 100-10,000 sqft
Exemplars: images of various houses
Generally these slots are present in all things. Each pair of a slot and a value specifies a typical
feature. The fact that houses are typically built of materials like wood and brick does not exclude
such possibilities as cardboard.
If the computer program has all these information then it can match the information with your new
information.
Generalization hierarchies
Supersets schemas are basically hierarchies' that e saw with semantic networks. In this case of
schemas, they are sometimes called generalization hierarchies. These hierarchies provide a lot of
information about an object.
Part hierarchy
Schemas have another type of hierarchy, called part hierarchy. Thus, Parts of houses, such as
walls and rooms, have their own schema definitions. Stored with schemas for walls and rooms we
would find that these have windows and ceilings. Thus, using the part relationships, we would be
able to infer that houses have windows and ceilings.
Schemas are designed to facilitate making inferences about the concepts. If we know something
a house, we can use the schema definition to infer that it is probably made of wood or brick, and it
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Cognitive Psychology ­ PSY 504
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has walls, windows, and the like. However the inferential processes for schemas must be able to
deal with exceptions.  It is also necessary to understand the constrains between slots of
schemas.
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Table of Contents:
  1. INTRODUCTION:Historical Background
  2. THE INFORMATION PROCESSING APPROACH
  3. COGNITIVE NEUROPSYCHOLOGY:Brains of Dead People, The Neuron
  4. COGNITIVE NEUROPSYCHOLOGY (CONTINUED):The Eye, The visual pathway
  5. COGNITIVE PSYCHOLOGY (CONTINUED):Hubel & Wiesel, Sensory Memory
  6. VISUAL SENSORY MEMORY EXPERIMENTS (CONTINUED):Psychological Time
  7. ATTENTION:Single-mindedness, In Shadowing Paradigm, Attention and meaning
  8. ATTENTION (continued):Implications, Treisman’s Model, Norman’s Model
  9. ATTENTION (continued):Capacity Models, Arousal, Multimode Theory
  10. ATTENTION:Subsidiary Task, Capacity Theory, Reaction Time & Accuracy, Implications
  11. RECAP OF LAST LESSONS:AUTOMATICITY, Automatic Processing
  12. AUTOMATICITY (continued):Experiment, Implications, Task interference
  13. AUTOMATICITY (continued):Predicting flight performance, Thought suppression
  14. PATTERN RECOGNITION:Template Matching Models, Human flexibility
  15. PATTERN RECOGNITION:Implications, Phonemes, Voicing, Place of articulation
  16. PATTERN RECOGNITION (continued):Adaptation paradigm
  17. PATTERN RECOGNITION (continued):Gestalt Theory of Perception
  18. PATTERN RECOGNITION (continued):Queen Elizabeth’s vase, Palmer (1977)
  19. OBJECT PERCEPTION (continued):Segmentation, Recognition of object
  20. ATTENTION & PATTERN RECOGNITION:Word Superiority Effect
  21. PATTERN RECOGNITION (CONTINUED):Neural Networks, Patterns of connections
  22. PATTERN RECOGNITION (CONTINUED):Effects of Sentence Context
  23. MEMORY:Short Term Working Memory, Atkinson & Shiffrin Model
  24. MEMORY:Rate of forgetting, Size of memory set
  25. Memory:Activation in a network, Magic number 7, Chunking
  26. Memory:Chunking, Individual differences in chunking
  27. MEMORY:THE NATURE OF FORGETTING, Release from PI, Central Executive
  28. Memory:Atkinson & Shiffrin Model, Long Term Memory, Different kinds of LTM
  29. Memory:Spread of Activation, Associative Priming, Implications, More Priming
  30. Memory:Interference, The Critical Assumption, Limited capacity
  31. Memory:Interference, Historical Memories, Recall versus Recognition
  32. Memory:Are forgotten memories lost forever?
  33. Memory:Recognition of lost memories, Representation of knowledge
  34. Memory:Benefits of Categorization, Levels of Categories
  35. Memory:Prototype, Rosch and Colleagues, Experiments of Stephen Read
  36. Memory:Schema Theory, A European Solution, Generalization hierarchies
  37. Memory:Superset Schemas, Part hierarchy, Slots Have More Schemas
  38. MEMORY:Representation of knowledge (continued), Memory for stories
  39. Memory:Representation of knowledge, PQ4R Method, Elaboration
  40. Memory:Study Methods, Analyze Story Structure, Use Multiple Modalities
  41. Memory:Mental Imagery, More evidence, Kosslyn yet again, Image Comparison
  42. Mental Imagery:Eidetic Imagery, Eidetic Psychotherapy, Hot and cold imagery
  43. Language and thought:Productivity & Regularity, Linguistic Intuition
  44. Cognitive development:Assimilation, Accommodation, Stage Theory
  45. Cognitive Development:Gender Identity, Learning Mathematics, Sensory Memory