[Human Memory] 10.Knowledge

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Human Memory10.Knowledge

• LEE JI HOON
• 2008.10.8

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Question

• 1. How do we access the information in generic
  memory?
• 2. How to add up your knowledge?

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What is knowledge?

• Knowledge is what you know.
• Generic memory
• Everyday, ordinary knowledge
• Includes other than purely semantic information
• In this chapter, we use generic than semantic
  memory

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Propositions and Concepts

• Concept
• A mental representation of something
• Singing, Canary, Justice
• Propositions
• A relationship between two concepts that has a
  truth value
• A canary can sing, A canary is a bird.

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Collins and Quillians Hierarchical Model
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Collins and Quillians Hierarchical Model

• Three assumption
• Retrieving a property and traversing the
  hierarchy take time.
• The times are additive whenever on step is
  dependent on the completion of another
• The time to retrieve a property is independent of
  the level of the hierarchy

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Collins and Quillians Hierarchical Model
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Collins and Quillians Hierarchical Model

• Problems
• No clear way of explaining performance on the
  false sentences.
• The Contradiction hypothesis search stops when a
  contradiction is reached
• Unsuccessful Search hypothesis search stops
  after a certain criterion is reached
• Search and Destroy hypothesis search continues
  until all possible connections are evaluated
• None of these gave a good account of performance.

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Collins and Quillians Hierarchical Model

• Problems
• There are often multiple representations and that
  structures may not be perfectly hierarchical.

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The Feature Overlap Model

• Defining feature
• Essential for defining a concept
• Characteristic feature
• Usually, but not necessarily, true of a concept.

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The Feature Overlap Model

• X, overall similarity
• C0, lower value
• C1, upper value

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Hierarchical vs Feature overlap

• More quickly A robin is a bird than A robin is
  an animal
• There are two levels of hierarchy to
  travel(hierarchical)
• There are more feature overlap b/w robins and
  bird
• More quickly A canary can sing than A canary
  can fly
• Explained by the ordering of features
• The most defining features are listed first

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The Feature Overlap Model

• Advantages
• It can handle false responses
• Which occur when the feature overlap b/w two
  concepts is very small
• It can handle different kinds of false responses.
• Magnesium is an animal is false than the
  proposition A tree is an animal
• Problems
• distinction between characteristic and defining
  features
• Different production frequency
• Butterfly -gt insect is often mentioned, insect -gt
  butterfly is rarely mentioned.

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Collins and Loftuss Spreading Activation Model

• Revision of the basic hierarchical model
• Activation spreads from one or two concepts to
  all related concepts.
• 1. Some concepts can be represented multiple
  times.
• 2. has links between concepts that have
  differential travel time.
• 3. Explicitly allows activation to spread from
  both category and exemplar nodes.

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Collins and Loftuss Spreading Activation Model

• Assumption
• 1. When a concept is processed, activation
  spreads out along all paths the strength of the
  activation decreases as the number of paths
  increases.
• 2. Only on concept can be processed at a time,
  but once processed, activation can spread in
  parallel.
• 3. Activation decreases over time and/or
  activity.
• 5. The more properties two concepts have in
  common, the more links there are between the
  concepts.
• 8. Decision process requires enough evidence to
  exceed a positive or negative criterion.
• Other assumptions but not mentioned in text.

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Collins and Loftuss Spreading Activation Model
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Collins and Loftuss Spreading Activation Model

• This theory is hard to disprove because it is
  difficult to predict and test
• It is best viewed as a framework than a precise
  testable model.
• This model quickly became a dominate explanation
  for theories of
• Generic memory
• Word production, word perception
• Spreading activation model explain association
  priming

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Conclusion

• It is not yet clear exactly how generic memory is
  organized.
• There is a limit on the amount of knowledge that
  a person can store and retrieve.
• The data that we do have suggest that the more
  you know about something, the easier it is to
  acquire new related information.