The Cognitive Science Approach

1
The Cognitive Science Approach

• Chapter 2

2
To Do List

• Research Methods
• The Information Processing Approach
• The Modern Cognitive Approach
• Brain and Cognition

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Research Methods

• Reaction Time
• Cognitive processes take time
• 12 10
• 46 59
• Accuracy (error rates)
• Tell us how information was being processed
• Verbal Protocols
• Verbalize thoughts as solve problems
• Neuroimaging

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Reaction Time
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Research Methods

• Reaction Time (RT)
• The time elapsed between some stimulus and the
  persons response to the stimulus
• Typically measured in milliseconds (ms)
• 1000 milliseconds 1 second

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Research Methods

• Accuracy Measures
• How many errors a subject makes
• Which are recalled correctly and which are not
• Types of errors
• e.g., KLXCRN ? KLXTRN
• Measured as proportion or correct

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Information Processing Approach

• The coordinated operation of active mental
  processes within a multicomponent memory system
• General model for memory and cognitive systems
• For many years was cognitive psychologys guide
  for research
• Where to start
• What to look for
• What to be aware of

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The Standard Theory of Information Processing
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The Standard Theory of Information Processing

• Atkinson Shiffrin (1968, 1971)
• Three memory components
• Sensory Memory
• Bring information from the environment to STM
• Short-Term Memory
• To/from LTM output
• Long-Term Memory
• Each step takes time
• Fixed order
• One at a time

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Lexical Decision Task(Word/Non-word RT Task)

• YES or NO, do the following letter strings form
  valid English words?
• 1) House
• 2) Glorp
• What are the mental steps/ stages involved in
  answering these questions?

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The Standard Theory of Information Processing
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Lexical Decision Task

• Encoding the stimulus
• Take in information and convert to a useable
  mental form
• Looking up the word in your internal dictionary
• LTM retrieval
• Deciding if it is a word or non-word
• STM
• Making a motor response
• STM

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A Process Model of the Lexical Decision Task
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Lexical Decision Task

• How do the RTs compare for
• Words vs. Non-words
• Frequent vs. Infrequent words
• Which stage of the Process Model?
• Word Frequency Effect
• What does this tell us about how words are
  stored? (50 ms difference)
• Pronounceable vs. Illegal non-words

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Information Processing Approach

• Any task consists of a number of stages
• Stages are completed in order
• Information passes from one stage to another
• Sequential stages
• Independent and non-overlapping stages of
  processing
• One stage finishes before the next begins

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Whats Wrong with Information Processing

• Parallel Processing
• Multiple processes happen simultaneously (in
  parallel)
• Your mind can do two things at once
• e.g., typing
• While one letter is being typed, another is being
  translated into a movement and the input stage is
  encoding up coming letters (as many as 8 letters
  in advance!)

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Whats Wrong with Information Processing

• Context Effects
• Process ROBIN faster if saw recently or were
  discussing birds recently
• Why it can be difficult to recognize someone out
  of context
• Everyday example

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Top-Down Processing or Conceptually-Driven
Processing

• When the existing context has an influence on
  mental processes
• In the example, reading is so automatic that
  youve learned to only pay attention to content
  words and ignore function words like of
• Most people say 3 ? really there are 6!

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Whats Wrong with Information Processing

• Not useful for studying complex cognition
• e.g., problem solving tasks
• Over reliance on RT measures
• Make inferences about mental processes just by
  having someone press buttons
• What about accuracy and verbal protocols which
  are important for more complex tasks

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Whats Wrong with Information Processing

• Was a good start
• Provided a testable model for how cognitive
  processes operate
• Dominant view in cognitive psychology until the
  mid-1970s
• Now use a broader, less restrictive approach ?
  cognitive science

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Updating the Theory (Neisser,
1976)
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Updating the Theory (Neisser,
1976)

• Parallel Processing triangle
• Different components can oporate simultaneously
• Context Effects bidirectional arrows
• Information in LTM can influence SM
• e.g., did you notice my spelling mistake above?
• Attentional Mechanism
• Open to a variety of research techniques

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Brain and Cognition

• We can study cognitive processes by studying the
  brain
• The goal is to understand (not how the brain
  works) what the brain can tell us about how
  cognitive functions work
• Two approaches ?

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Brain and Cognition

• Cognitive Neuropsychology
• Analysis of those handicaps in human cognitive
  function which result from brain injury
• K.C. motorcycle accident ? no ability to
  remember anything from his past (playing chess
  with someone last week) but still remembers facts
  (e.g., how to play chess, who is the President)
• Dissociation a disruption in one component of
  memory but no impairment of another
• What does this tell us about memory?

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Brain and Cognition

• Brain Imaging
• Are different brain areas active when you
• read apple
• see an apple
• imagine an apple

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Coglab

• www.coglab.wadsworth.com
• Students
• Access Your Account
• Logging on
• IDs and passwords
• Registration E-Pin
• User Information Name Password
• The experiments