Methods of Cognitive Neuroscience

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Methods of Cognitive Neuroscience

• How do we accomplish our goals?

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Science

• What is science?
• What is the purpose of science?
• Is Science about finding Truth?

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Whither Cognitive Science?

• How do we observe something that cant be seen?
• How do we theorize about something that cannot be
  observed?
• We have to really know what it is were analyzing.

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What were studying

• What were looking at is how the mind processes
  information.
• What does that mean?
• Process and Representation

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Representation

• The manner in which information is stored in the
  mind.
• Analogous to different representations on a
  computer - text, JPG, MP3, WMV, etc.

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Process

• The means by which those representations are
  manipulated.
• Once again, we can use the computer analogy
  e-mail, Word, iTunes, Quicktime, etc.

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Cognitive Research Methods

• Task Difficulty - Different combinations of
  processes and representations should make
  different types of tasks more or less difficult.
  Determining which properties of tasks make them
  easier or harder can shed light on what processes
  and representations are being used.
• Reaction time
• Error rate
• Task performance time
• Ex the Chinese Ring puzzle

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More methods

• Task Performance - examine how people perform
  various tasks to try and understand the
  underlying processes and representations
• Verbal protocols
• Eye tracking
• Mouse tracking
• Brain-damaged patients

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Two Goals

• Localization of function - At the macro level,
  Cognitive Neuroscience tries to examine where in
  the brain various cognitive operations take
  place.
• Neural computation - At the micro level, we try
  to understand how the brain performs various
  operations.

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Localization of function

• Post-mortem lesion studies - Find someone who
  displays an interesting cognitive deficit. When
  they die, study their brain for where the damaged
  tissue was. (Phineas Gage, Brocas Wernickes
  areas)
• Human-lesion studies - These days, we can take
  pictures of the brain while its still in the
  skull (CAT, MRI) an determine where the lesions
  are while someone is still alive. (Prosopagnosia,
  optic aphasia)

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More localization

• Animal lesion studies - Human lesions are messy
  and uncontrolled. No two people ever have the
  exact same lesion. With animals, we can control
  the characteristics of the lesions. (Area MT)
• Single-cell recording - Also with animals, we can
  attach electrodes to neurons and measure the
  firing pattern of individual neurons. (Feature
  detectors in area V1)

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But wait! Theres more

• Brain imaging - Modern technology provides us the
  ability to, in very broad strokes, examine what
  the brain is doing while a person is actively
  performing a cognitive task. (Face recognition,
  spatial processing)
• Brain stimulation - People are kept awake during
  brain surgery. Use the opportunity. (Motor and
  somatosensory homunculi)

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Neural computation

• Physical modeling - Understand the properties of
  neurons, how they share information and what-not,
  and try to understand how these properties can
  lead to complex computations. (opponent
  processes, how feature detectors are calculated).
• Computational modeling - Neural networks are
  computer models of how groups of neurons behave.
  Use these models to try and better understand
  cognitive processing in the brain.