Episodic and semantic memory

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Lecture 503-12-2007

• Episodic and semantic memory

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Plan

• Contents of episodic memory
• Irrelevant memories
• Repetition and practice
• Organization and distinctiveness
• The remember/know distinction
• Organization of semantic memory
• Episodic and semantic memory a comparison
• Relations between episodic and semantic memory
  the SPI model

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Introducing remarks

• Episodic memory memories of events that we
  experienced, concerns ones own past and facts
  personally experienced, possible to locate in
  time and space
• Semantic memory other than personal character,
  contains general world knowledge necessary for
  language use shared with other people

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Contents of episodic memory serial position
effects

• Primacy effect superior memory for items at the
  beginning of a sequence
• Recency effect superior memory for items at the
  end of a sequence
• Both effects are present in STM and LTM, but
  their interpretations are different
• In STM, the primacy effect is representing
  long-term storage, the recency effect short-term
  storage
• In LTM, the primacy effect may reflect higher
  distinctiveness, novelty, lower interference the
  recency effect higher distinctiveness, lower
  forgetting effects both lower interference

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Contents of episodic memory levels of
representation

• Craik and Lockaharts levels of processing
  framework deeper, semantic encoding leads to
  stronger memory traces shallow processing leads
  to weak memory traces
• Texts representation surface form, text base and
  mental model
• Surface form is forgot quickly, text base had a
  more durable retention, mental model remembered
  over long periods of time

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Episodic memory retention for information at
different levels of representation
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Contents of episodic memory recall cues

• Recall or retrieval cue a prompt directing
  retrieval
• Cues in general improve retrieval because the
  information in the cues is also present in the
  memory traces
• Types of cues feature cues and context cues
• Feature cues involve components of the memory
  itself self is a very powerful memory cue (the
  self-reference effect)
• Context cues involve parts of the environment
  linguistic, external and internal context

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Contents of episodic memory context

• Encoding specificity principle
• Godden and Baddeleys study with divers as an
  example of memory depending of external context
• Probably stronger for recall than recognition
• Does it matter where students take exams?
• Evidences for a context effect with music and
  odors (Proust effect)
• State-dependent memory alcohol, nicotine,
  marijuana

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External context Godden and Baddeleys study
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State-dependent memory sober or intoxicated
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Mood-dependent and mood-congruent memory

• It is easier to recall positive stimuli when in
  positive mood, and negative stimuli when in
  negative mood
• Recall is better if people are in the same mood
  as when encoding the information
• A negative role of the effect in depression
• Maybe encoding specificity and state-dependent
  memory are forms of mood-congruent memory

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Transfer appropriate processing

• Memory is better when at retrieval the same or
  similar mental processes are used as at encoding
• Overall memory is better when encoding in a
  semantic way (Craik and Lockharts levels of
  processing theory), but
• the effect of the matching between encoding and
  the memory test may be very strong
• Semantic processing had a stronger positive
  impact on explicit memory tests shallow
  processing on implicit memory tests

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Irrelevant memories interference

• Negative transfer prior learning impedes the
  ability to learn new information
• The amount of negative transfer is a function of
  the degree of overlap between the old and new
  information
• Proactive interference old knowledge results in
  the increased forgetting of new knowledge (or
  greater difficulties in retrieval)
• Release from proactive interference Wickens
  procedure

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Stimulus lists from proactive interference study
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Results from a study of release from proactive
interference
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Retroactive and associative interference

• Retroactive interference occurs when new
  knowledge makes it difficult to recall old
  knowledge
• How the delay time before recall is spent matters
  for the interference effect it is better to go
  to sleep after learning than learning something
  else
• Associative interference due to associations
  linked with items and not to the temporal
  sequence
• Fan effect the more you know, the harder it is
  to remember new information.Is it always the
  case?

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How to reduce interference?

• Extensive practice
• Learning dissimilar materials one after the other
• Change learning strategies
• Change the context of learning
• Make pauses
• Inhibition part-set cuing directed forgetting
  negative priming repeated practice effect

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Repetition and practice

• Repetition effect the more a person is exposed
  to information, the more likely it will be
  remembered
• Massed practice (learning in a single, lengthy
  session) and distributed practice (spaced
  practice), distributed across multiple study
  sessions
• In general, memory is better following
  distributed practice than massed practice
• The longer the spacing between the distributed
  practices, the better the memory
• But massed practice provide higher reminiscence

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Effects of massed versus spaced practice on
subsequent memory
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Why spaced practice gives better results as
compared to massed practice?

• Deficient processing with massed practice
  consolidation is worse and concerns one memory
  trace habituation occurs with massed practice
  and the level of attention is lower as the
  memory traces are fresh, people assume they
  remember better and devote less time and effort
  to learning
• Encoding variability the contexts in massed
  practice are the same giving less retrieval cues
• Dual processes both deficient processing and
  encoding variability

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Overlearning and permastore

• Overlearning practice of the already memorized
  information
• Overlearning strengths memory traces and
  increases resistance to forgetting
• Bahricks studies on the retention of school
  materials an initial period of forgetting of
  about three years and stable retention after
  (permastore)
• Forgetting occurs at about the same rate for
  everybody, so knowing more at the beginning means
  having larger knowledge in permastore

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Organization and distinctiveness

• Organization of the to-be-remembered-information
  improves episodic memory
• Subjective organization is especially helpful,
  although it takes more time and effort
• Distinctiveness items that are different (more
  salient or unique) from other items are better
  remembered
• Bizarre imagery bizarreness may help memory, but
  the effect is less universal than it is claimed
• Interactive imagery usually proves to help memory

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The remember/know distinction

• Remember judgments reflect the belief that an
  event occurred evidence of episodic memory
  (autonoetic I know that I know)
• Know judgments reflect a feeling of familiarity
  evidence of semantic memory (noetic I know)
• A double dissociation between these two types of
  responses
• Nondeclarative (procedural) memory is considered
  as being anoetic (unconscious) I don't know
  that I know

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Factors affecting remember but not know

• Depth of processing
• Generation effects
• Frequency of occurrence
• Divided attention at encoding
• Retention interval
• Reading silently or aloud
• Intentional versus incidental learning
• Serial position

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Factors affecting know but not remember

• Repetition priming
• Stimulus modality
• Amount of maintenance rehearsal
• Suppression of focal attention

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Factors affecting rememberand know in
opposite ways

• Word versus nonword memory
• Massed versus distributed practice
• Gradual versus abrupt presentations
• Learning emphasizing similarities versus
  differences
• Different neurological mechanisms for both types
  of responses

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Organization of semantic memory

• Concepts and categories prototype theory
  exemplar theory explanation-based theory
• Ordered relations semantic distance effect
  semantic congruity effect serial position effect
• Schemas and scripts
• The organization of semantic memory is described
  by some of the long-term memory models reviewed
  in lecture 4

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Differences between episodic and semantic memory
information
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Differences between episodic and semantic memory
operations 1
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Differences between episodic and semantic memory
operations 2
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Differences between episodic and semantic memory
usage
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Relations between memory systems Tulvings SPI
model

• The relations between three main memory systems
  of perceptual representation, semantic memory and
  episodic memory are specific in relation to
  processes
• Encoding has a serial character (S)
• Storage is parallel (P)
• Retrieval is independent (I)
• Systems are organized in a hierarchical way
• Different aspects of the information are
  separately stored in each system

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Schematic SPI model