BCS 111 Lecture 7.2

Principles of visual imagery (Finke 1989)

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Implicit encoding

features in an object

• Can you picture mentally what the library reading room is like?

Perceptual equivalence

imaging an object similar to actually perceiving it

Perceptual equivalence (cont)

mentally imaging an object is similar to actually perceiving it

• activation of fusiform face area (FFA) while seeing the actual face AND forming a mental image of it!!

Spatial equivalence

amount of time it takes to mentally scan from A to B is a function of the actual distance A-B in the image

Spatial equivalence: how to test this

Results from Kosslyn (1983)

• The longer the distance in the image, the longer the scanning RT

  • The distance between objects on the image is just like the “distance” between objects in our mind!

Blind people

Spatial equivalence: also applies to blind people- they learned through tactile senses

• Form a mental “sketch” of the object by touch

• When asked to mentally scan an image or object “without” seeing it, spatial equivalence is also found in blind people.

Transformational equivalence

rotating an object similar to rotating a mental image

Structural equivalence

features of imaged object similar to actual obj.

How to test Structural equivalence: Kosslyn et al. (1983)

(cont)

Key manipulation:

• Complexity of the verbal description: one group receives complex descriptions and another receives simple ones

• (e.g., 9 small circles vs. a big circle)

Structural equivalence: Kosslyn et al. (1983)

Finding 1:

• Positive correlation between RT and # of parts

  • Complex objects require longer time to image

(cont)

Finding 2:

• Complex description

  • slower

  • Effect of language on structural complexity

Interaction between the mental 3D space and the actual environment- Spatial cognition

• Knowing where we are

• Knowing where to go

  • e.g. Navigate through your room without lights