Mental Imagery

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Mental Imagery

• The evidence in favor of us seeing actual
  pictures in our mind.

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Mental Rotation

• Shepard Metzler (1967) did the classic mental
  rotation experiment.
• Show people two arbitrary, 3-D objects at
  different orientations.
• Ask people to judge whether the objects are
  mirror images of each other or not.
• The amount of time it takes people to answer is
  directly proportional to the degrees of rotation
  by which the objects differ.

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Relative size Image scaling

• When asked to imagine two objects, it takes
  longer to make judgments about the smaller object
• It also takes longer to make judgments about
  smaller features of objects

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Image scanning

• Give people a picture of something, such as a map
  of a simplistic island and have them memorize it.
• Ask people to scan the image from one point on
  the map to another.
• The time it takes to do this is proportional to
  how far apart the two points are.

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The Minds Eye hypothesis

• Kosslyn proposed that mental imagery is
  functionally equivalent to vision.
• What he means by this is that mental imagery uses
  the same internal representations and processes
  that vision does, but without visual input.

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Could it be true?

• fMRI experiments indicate that the occipital lobe
  and other early visual areas are active during
  imagery tasks.
• Single-cell recording in monkeys shows that areas
  activated during training for a task also become
  activated when the monkey simply imagines
  performing the task.

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Which do you believe?