Nondeclarative memory

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Lecture 610-12-2007

• Nondeclarative memory

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Plan

• Introducing remarks
• Procedural memory cognitive, associative and
  autonomous stage
• History of research on implicit memory
• Indirect tests of implicit memory
• Role of implicit memory
• Theoretical explanations of nonconscious forms of
  memory

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Nondeclarative memory main phenomena

• Savings
• Classical conditioning
• Operant conditioning
• Incidental learning, eg. artificial grammar
• Learning to react on repeated stimuli sequences
• Skill acquisition
• Simulation of control of complex systems
• Implicit memory

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An example of study on skill acquisition

• Singley and Andersons study of the acquisition
  of editor usage skills
• Practice for 6 days, 3 hours a day
• Time needed for corrections became shorter 8
  minutes on the first day to 2 minutes on the
  sixth day
• Analysis of the writing and thinking time

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Results obtained in the Singley and Andersons
study
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Power law of learning (practice)

• Learning never ends, but with practice benefits
  are getting smaller
• Previously it was assumed that learning is best
  described by an exponential function
• Newell and Rosenbloom almost all functions
  describing learning are power functions, no
  difference what kind of effects are measured
  execution time (gets shorter), the number of
  errors (smaller)

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Examples of learning functions
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Power law of learning

• The power function is negatively accelerated
• A good illustration of different levels
  phenomena
• Behavior
• Changes in long term potentation (LTP)
• Probability of the repetition of information or
  events in the environment
• Human and animal learning

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Skills in performing logic proofs
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Time needed to produce one cygar and write one
book
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Main stages of skill aquisition

• Cognitive stage (declarative) the
  representation of the skill is a declarative one
• Associative stage (compilation) the declarative
  representation is gradually changing into a
  procedural one
• Autonomous stage (procedural) the skill becomes
  automatic and is executed fast, cognitive
  involvement is eliminated the skill is
  transferred to unconscious memory

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Cognitive stage

• Close relations to problem solving
• May be described using artificial intelligence
  approach
• Newell and Simon General Problem Solver
• State
• Goal
• Operators
• Discovering appropriate operators

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Why is it difficult to find the right operator?
The Hanoi Tower problem
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Associative stage

• At this stage people stop using general problem
  solving methods and start to use methods specific
  for the domain
• Declarative knowledge is gradually transformed
  into procedural one
• Learning of domain specific procedures is called
  proceduralization
• When executing the skill, people recognize
  patterns and by the same put less load on working
  memory

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Production rules

• Procedural knowledge has the form of production
  rules If... then...
• Complex cognitive skills require many production
  rules chess players know about 50 000 production
  rules mathematics in secondary school requires
  from 1 000 to 10 000
• Novices and experts have not only a different
  number of production rules, but their production
  rules are also different

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Autonomous stage

• With practice skills change by adding new rules
  and enhancement of existing rules
• The skill becomes more automated, requires less
  attention and there is less interference with the
  execution of other tasks
• Studies by Spelke, Hirst and Neisser
• It is possible to execute in parallel more than
  one task at the condition that at least one of
  them has an automatic character (a motor program)

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Motor programs general or specific?
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How are motor programs aquired?
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Good and bad sides of automatic skill execution

• Good fast and easy execution small cognitive
  involvement possibility of executing other tasks
  at the same time
• Problems the execution once started is difficult
  to interrupt errors in cases of condition
  changes low transfer

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Expertise

• Becoming an expert means
• acquiring many production rules
• procedural memory in the domain becomes automatic
  and autonomic
• larger declarative domain knowledge
• better coordination of information, especially on
  retrieval due to long-term working memory cues
• In Ericssons opinion skilled memory enables
  exceptional achievements

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History of research on implicit memory

• Ebbinghaus conscious incidental memory and
  unconscious incidental memory
• Hysteric amnesia anxiety as a reaction in
  situations or places associated with trauma
• Claparède observations concerning a patient with
  hysteria
• Korsakow reactions of patients to the apparatus
  for electric shock therapy

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Other examples of unconscious memory

• Damasio Daniels case
• Memory under anesthesia
• Effect of mere exposition
• Tip-of-the-tongue phenomenon
• Learning native language by children
• First controlled experiments Warrington and
  Weiskrantz (1970) on amnesic patients
• Graf and Schacter (1985) introduction of the
  concept of implicit memory

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Methods for study implicit memory perceptual
tests

• Tests which do not require conscious or
  intentional recall or recognition but allow in an
  indirect way to discover the impact of some
  memories
• Repetition priming in the first phase the
  presentation of stimuli in the second a test
• Jacoby the procedure of perceptual
  identification in a very short exposition
• Tulving word fragment or stem completion

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Conceptual or associative tests

• Associative (semantic) priming exposition of
  exemplars from a given conceptual category
• Questions concerning general knowledge
• Free associations

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Conscious and unconscious memory

• Dissociations between populations
• Amnestic patients and control
• Children and adults for example recognition of
  pictures and latencies of labeling previously
  seen pictures as compared with new ones word
  fragment completion identification of word
  fragments
• Old adults
• Unconscious forms of memory are relatively stable
  across life-span

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Functional dissociations

• In subjects without memory disturbance different
  factors affect direct (explicit) and indirect
  (implicit) memory
• Results of direct memory tests are, and of
  indirect memory tests are not under the influence
  of
• Level of processing
• Attention
• Intention
• Organization of the material
• Alcohol

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Level of attention and results in direct and
indirect tests of memory
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Conceptual and perceptual processing test
material
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Conceptual and perceptual processing results
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Functional dissociations cont.

• Indirect tests are more under the impact of
• Differences in perceptual features, for example
  changes of modality
• Changes in one modality (male versus female
  voice pictures versus words)
• Jacobys study XXX COLD HOT COLD HOT?
• Perceptual identification the best when words
  were perceived without context recognition the
  best when words were generated by subjects

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Results of Jacobys study
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Stochastic independence

• The results of indirect memory tests can not be
  predict on the basis of results from direct
  memory tests and vice versa
• Conscious and unconscious memory effects of the
  same material are independent one from the other
• No correlation between recognition and word
  fragment completion of the same words
• Recognition of mates from maternal school on the
  basis of pictures and electrodermal reaction

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Similarities in determinants of conscious and
unconscious memory

• Retention time and practice
• Number and spacing of repetition
• Context
• Similarities found more often when conceptual
  indirect tests are used

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Interpretation problems

• Main difference in research instruction to
  recall or not
• But do always subjects behave in the way the
  experimenter is awaiting of them, especially in
  the case of indirect memory tests?
• And are conscious memory tests always performed
  without hidden processes?
• Dissociation of processes subjects are
  instructed to include or not to include the
  presented words

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Theoretical explanations

• First one, soon rejected the strength of memory
  traces and threshold hypothesis
• Activation hypothesis based on an associationist
  approach to memory for unconscious memory a
  brief activation of memory traces is sufficient
  conscious memory requires the access to the nodes
  and context

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Memory systems interpretation

• Conscious and unconscious memory depends on
  different, separate memory systems
• An interpretation popular among
  neuropsychologically oriented researchers the
  evidence would be dissociations
• Tulving and Schacter distinction of perceptual
  representation system, responsible for perceptual
  priming effects and semantic memory system
  responsible for conceptual priming effects
• Squire a nondeclarative system

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Information processing

• Different encoding processes called up by direct
  and indirect memory tests
• Role of the interaction between the features of
  the memory representation and task demands
• Data-driven (bottom-up) processing more
  important for implicit memory, and conceptually
  driven (top-down) processing more important for
  explicit memory

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What is implicit memory for? Positive role

• Makes easier the identification of perceptual
  stimuli
• Makes easier semantic processing
• Automatic execution of some skills
• Possibilities for the rehabilitation of amnesic
  patients Barbaras case trained by the
  procedure of disappearing cues
• Advertisement

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Some negative consequences of implicit memory
acting

• Stereotypes
• Unconscious plagiarism cryptomnesia (source
  monitoring error)
• Déjà vu
• False fame effect

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False fame effect