Methods and principles

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Lecture 22009-11-09

• Methods and principles

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Plan

• Components of memory research
• Aspects of learning
• Assessing the contents of memory
• Assessing memory structures and process
• Conscious and unconscious experiences of memory

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Why is it difficult to investigate memory?

• People have little conscious awareness of mental
  processes, including memory
• so, for a long time memory was thought to be
  beyond objective, scientific study
• Because of its hidden character, memory is
  usually investigated with indirect methods
• On the basis of observations, and for most parts
  on the basis of retrieval results, psychologists
  make inferences about the course of encoding and
  storage

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Components of memory researchwhat an experiment
is?

• An experiment is a controlled situation in which
  the researcher manipulates independent variables
  and measures the effects of this manipulation on
  the dependent variables
• As many irrelevant, control variables as possible
  should be controlled or kept constant
• Subjects should be randomly assigned to different
  conditions

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Components of memory researchother than
experiment types of studies

• Correlational studies
• Quasi-experimental studies
• Case studies

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Aspects of learningintentional versus
incidental learning

• Intentional learning explicit memorization
• as opposed to incidental learning
• In intentional learning tasks, participants are
  explicitly asked to memorize the presented
  material
• In incidental learning participants might be
  asked to perform different operations on the
  material, like rating or sorting

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Intentional versus incidental learning levels of
processing 1

• Levels of processing Craik and Lockhart (1972)
• Shallow or rote rehearsal in general recall
  ability does not change with more rote rehearsal,
  for example Glenbergs, Smiths and Greens
  (1977) study with words, Nickersons and Adamss
  (1979) study with pennies, and professor
  Sanfords case

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The material used in Nickersons and Adams study
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Intentional versus incidental learning levels of
processing 2

• Elaborative rehearsal using prior knowledge,
  making inferences, thinking about the meaning,
  organizing
• Questions leading to shallow processing how the
  word is printed? What is the color of the print?
• Questions leading to more elaborative processing
  is the word a rhyme of another word?
• Questions leading to deep processing does the
  word describe the member of a given category?
  Does the word make sense in a given sentence?

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Intentional versus incidental learning imagery

• In general forming mental images have a
  beneficial effect on memory
• Dual Code Theory (Paivio, 1969) people store
  information in memory in at least two forms
  verbal/linguistic code and mental image code
• Better memory effects are due to the fact that
  multiple coding gives more retrieval paths

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Impact of mental imagery on memory results
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Intentional versus incidental learning generation

• The generation effect information generated by
  the learner is remembered better than information
  only perceived by the learner
• The aha effect or insight in problem solving
  the solution found by the learner itself is
  better remembered
• The enactment effect memory is better when
  people actually perform a task in comparison to
  watching someone else performing it

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Intentional versus incidental learning
automaticity

• Memory is similar under incidental and
  intentional encoding conditions when
• recognition tests are used
• information concerns frequent everyday activities
  or events
• learners are very young and/or do not use
  effective memory strategies

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Stimulus characteristics

• When devising experiments in memory the following
  characteristics of the stimulus should be taken
  into account familiarity, level of difficulty,
  complexity, affective valence...
• The objective charactersitics do not have the
  same subjective value for all learners
• The nominal and the functional stimulus is led
  a nonsense syllable? And lis?

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Stimulus characteristics 1

• Savings after information has been learnt and
  forgotten, a person needs less effort to relearn
  it prior knowledge and experiences with a given
  material influence actual learning
• Picture and concreteness pictures are usually
  remembered better than words (picture superiority
  effect) concrete words are remembered better
  than abstract ones (concreteness effect)

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Stimulus characteristics 2

• Emotional valence people exhibit tendency to
  better remember positive than negative
  information (the Polyanna principle), and
  emotionally neutral information worse than
  positive and negative
• Frequency high frequency is better for recall
  tests, low frequency better for recognition tests

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Assessing the contents of memory recall

• Types of recall test
• Free recall number of recalled elements, errors
  of omissions, errors of commission (intrusions),
  recall order, organization
• Forced recall
• Cued recall, for example paired associate
  learning tasks
• Retrieval plans formed by subjects

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Recall principles

• Forgetting curve the amount of recalled
  information becomes smaller with time
• the forgetting curve is a negatively accelerating
  function the rate of forgetting is most rapid
  initially after learning with time the rate of
  forgetting slows down
• this principle is a very general one and can be
  observed with every kind of information, although
  the recall of one kind of material odors does
  not strictly follow this principle

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Forgetting curves
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Recall overlearning, reminiscence and hypermnesia

• Overlearning occurs when a person continues to
  rehearse after being able to produce a perfect
  recall the information becomes resistent to
  forgetting and to the destructive influence of
  stress
• Reminiscence recall of information that was once
  forgotten better recall after a delay than
  immediately after learning
• When one tries to recall information several
  times in a row, the rate of reminiscence may be
  greater than the rate of forgetting (hypermnesia)

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Recognition methods

• Recognition a matching process in which stimuli
  from the environment are compared with the
  contents of memory (memory traces)
• Old-New recognition the subject is given an item
  and asked to indicate whether it is old or new
• Correction for guess for example by subtracting
  the number of incorrect responses from the number
  of correct responses
• Guessing is affected by difficulties in
  discrimination between new and old items, and may
  be the result of biases

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Recognition the Signal Detection Theory

• Signal Detection Theory is a method for
  estimating discrimination and biases in
  recognition
• Its source psychophysics
• Assessment of the ability to detect the signal
  (accurate memory) from the noise (inaccurate
  memories)
• There are two distributions one for the old
  items and one for the new items along the
  familiarity dimension

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The Signal Detection Theory
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Forced choice recognition

• People are given several items and are asked to
  indicate which one is old or correct
• The basis of many (most?) educational test
• Often taking the form of multiple choice test
• Errors can be a source of knowledge about the
  contents of memory, after correction for guessing

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Social influences on memory tasks

• Collaborative inhibition a decline of
  performance in recall when working in a group as
  compared with performances when working in social
  isolation but recalling in groups does increase
  the accuracy of the recalled information
• Collaborative facilitation recognition is better
  in group settings
• The gains concern especially hits, correct
  rejection benefit less from group work

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Assessing memory structure and process mental
chronometry

• An important measure response time (reaction
  time) the speed of responding
• Faster response times reflect simpler memory
  processes and/or more familiar memories
• Slower response times reflect more complex
  processes and/or more unfamiliar memories
• Response time is measured from the onset of the
  stimulus

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Mental chronometry subtractive factors logic

• The response time is measured at least twice in
  two conditions differing in one step in
  processing
• The time for the simpler process is subtracted
  from the time for the more complex one the
  result shows the time needed for the performance
  of the extra process
• But we do not know if the introduced extra
  process did not disturb the course of the primary
  process

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Donderss subtractive factors logic for response
times a graphic illustration
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Mental chronometry additive factors logic

• The additive factors logic, developed by
  Sternberg
• The response time is measured at least twice, in
  two conditions in both the extra process (or
  step) is present, but conditions differ as to the
  extent of required processing
• The differences in response times show the
  influence of each increment of complexity

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Sternbergs additive factors logic for response
times
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Priming

• Priming means a speeding up of response time to
  information that follows another related with it
  information
• For example lexical decision tasks, quicker
  recognition of words or pictures preceeded by a
  semantically related word or picture
• Priming may be subliminal or may occur on the
  level of conscious perception

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Cluster analysis methods

• Inter-item delays recording of the time delay
  between each recalled item
• Usually people report some items, make a pause,
  report next few items, again make a pause and so
  on
• ARC scores (Adjusted Ratio of Clustering)
  analysis of the order in which information is
  reported, for example in categories or in a
  sequential order

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Cluster analysis subjective organization

• The organization imposed by the learner itself,
  especially when there is no clear a priori
  organization
• It may take the form of an ordered cluster tree
• Learners are asked to recall the same complete
  set of information many times and the
  experimenter looks for consistencies in the
  recalls in terms of their organization

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Cluster analysis principles

• Memories are highly structured
• Some information is organized in the form of a
  hierarchy, some other in temporal sequences
• Higher organization is linked with better recall
• Experts in a domain have highly organized
  knowledge bases
• When the structure of a material is difficult to
  discover, people tend to impose their own
  subjective organization on it

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Conscious experiences of memory metamemory
measures

• Metamemory the awareness of ones own memory and
  memory processes
• Metamemory may be studies by means of verbal
  reports (thinking aloud) remember versus know
  judgments feeling of knowing experience
  questionnaires
• People are in general quite good in assessing the
  contents of their memory
• An exception is for example the hindsight bias
  (knew-it-all-along effect)

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Implicit memory

• Implicit memory refers to memories and memory
  processes that are unconscious
• Measured by tasks in which people are not aware
  that their memory is being tested
• Examples of implicit memory test word fragment
  completion, perceptual identification, perceptual
  and semantic priming
• The process dissociation procedure help the
  estimation of the relative influence of explicit
  and implicit memory processes