Overview of LongTerm Memory

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Overview of Long-Term Memory

• laura leventhal

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Reference

• Chapter 14

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Learning and LTM

• The major task of learning new material is to
  integrate it into the existing structure of
  information that is already in LTM.
• Rehearsal is useful to retaining information in
  STM and Working Memory
• LTM requires rehearsal and integration
• Integrated information in LTM is KNOWLEDGE

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Features of LTM

• LTM is permanent memory (as opposed to STM or
  working memory)
• LTM has essentially infinite capacity. It is an
  open question whether people ever truly forget
  information that is stored in LTM.
• LTM has slower access compared to STM
• 1/10th of a second vs. 70 ms

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Features of LTM (2)

• Information gets into LTM from STM, via rehearsal
  Getting information out of LTM is called
  retrieval. Information can be in two ways,
  recall or recognition.
• In recall, information to be retrieved from LTM
  must first be found and then recalled. In
  recognition, an informational cue is provided and
  the information retrieved is matched against the
  presented cue.
• Designer Lesson
• Generally recall is more difficult than
  recognition. You will probably remember that in
  our discussion of interaction styles, we
  mentioned that menus may be easier for novices to
  use as compared to command line interactions.
  Why - with menus, all options are presented
  explicitly, so selecting a menu option involves
  recognition. When using command line
  interactions, generating a command involves
  recall.

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Information can be accessed in different ways

• LTM stores different sorts of information
• Information can be retrieved or accessed in
  different ways
• For example
• people have excellent recognition memory ("I
  always remember a face", deja vu) -but may do
  less with at retrieving linguistic label (name)

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Types of knowledge in LTM

• Information in LTM is organized into two types of
  knowledge declarative knowledge and procedural
  knowledge.
• Declarative knowledge or knowledge of facts
  indicates "knowing what". An example of
  declarative knowledge is knowing the answer to
  the following question "what is the capital of
  Ohio?" Declarative knowledge is easy to
  communicate
• Procedural knowledge is knowing how to do". In
  general, procedural knowledge may be more
  difficult to communicate.
• Designer LessonIn some of our recent work, we
  have used dual presentations of text and visuals
  to convey procedural information. In particular,
  virtual reality presentations seem to be quite
  effective in presenting this type of information.

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Representation of Knowledge

• Knowledge is organized 1 hierarchically
  (represents categories), 2 temporally
  (represents sequences) and in 3 networks
  (represents complex connections).
• Both the information and its organization changes
  over time. We observe that the organization of
  information in LTM supports our memories of
  episodic events to experiences in temporal
  order.
• An expert has developed a complex, multi-level
  body of knowledge in their domain of expertise,
  stored in LTM.

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Representation of Knowledge (2)

• Some knowledge is semantic or about meaning.
  Semantic knowledge is knowledge of general
  concepts, independent of a specific situations.
  For example, an expert programmer understands the
  concept of array regardless of the programming
  language.
• Some knowledge is syntactic or about surface
  structure. Syntactic knowledge is also stored in
  LTM, but it is more detailed than semantic
  knowledge and is less (cognitively) structured.
  Knowing the format of the C while structure is
  an example of syntactic knowledge. Syntactic
  knowledge is more easily forgotten than semantic
  knowledge.
• Semantic knowledge is acquired through demanding
  and meaningful problem-solving.
• Syntactic knowledge is acquired by rote. The
  acquisition of new syntactic information may
  interfere with previously-learned syntactic
  knowledge or vice versa. Hence, programmers
  often have much difficulty learning a second
  programming language.
• There are vast individual differences in the
  quality and capabilities of building
  informational structures in LTM. Also children
  and adults differ. Adults have an existing
  informational structure. Their challenge is to
  integrate new concepts into the existing
  structure. .Children on the other hand are
  building their DB so much of what they do is
  concept learning and formation.
• Designer Lesson Even within a narrow group,
  ability to integrate new concepts will vary
  tremendously.

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Learning - construction of knowledge

• Learning is a key focus of cognitive psychology
  and has been the subject of many studies and
  experiments.
• Here is a short summary about learning.
• Learning is the process of building knowledge
  this may involve the formation of concepts.
• Learning is complex.
• Learners are not passive absorbers of
  information.
• Learning involves the integration of new
  information and experiences with our existing
  structures.
• What we learn may be wrong.
• We learn by rehearsal, doing, vivid experiences
  and through analogies.

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Learning - Designer Lessons

• Research in HCI has suggested that people learn
  to use computer systems most effectively if
  learning is active..
• Consider having users engage in actual interface
  tasks not long bouts of manual reading. Active
  learning may also be enhanced if user makes
  errors and receives useful feedback.
• Set goals where action sequence is obvious.
• Use analogies

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Skill Acquisition

• Some CHI activities involve skill acquisition or
  use of skill rather than complex knowledge. There
  are many laws of human factors that one can use
  in design. These generally apply to sensory-motor
  skills rather than knowledge.
• For example, the power law of skill acquisition
  suggests that our improvement is fast at first
  then much slower. When you learn to do something,
  like use a mouse, you improve quickly at first..
  Subsequent improvements take longer. The more
  that you practice, the faster that you get
  though.
• The power law states that task time on the nth
  trialTn T1n-.4 where n is a constant for task

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