Mental Imagery in Perception

This is my second entry on mental imagery, this time on the role mental imagery plays in everyday perception.

Mental imagery: Perceptual processing that is not triggered by corresponding sensory stimulation in the relevant sense modality.

This covers a lot of things:

  • Blind spot
  • Peripheral vision
  • Some optical illusions (like neon color spreading)

spreading

  • Amodal completion
  • Multimodal completion

Focus here is on amodal completion.

Claim: in the vast majority of cases, perception depends constitutively on mental imagery. Because of amodal completion.

Amodal completion: the representation of occluded parts of perceived objects.

completion

It is used in perceiving almost all everyday scenes (because every non-transparent object occludes what’s behind it and all three dimensional non-transparent objects self-occlude).

((almost all because in the case of simple two-dimensional displays (of, say, a triangle, we do not get amodal completion))

  • Amodal completion is a form of mental imagery (it is perceptual processing that is not triggered by corresponding sensory stimulation in the relevant sense modality)
  • In the vast majority of cases, perception depends constitutively on amodal completion.

General picture of perception: it is (almost) always a mixture of sensory stimulation-driven perceptual processing and mental imagery (perceptual processing that is not sensory stimulation-driven).

crawling

Multimodal completion: up next …