Development of depth perception

1
Development of depth perception

• First convergence not perfect (immature eye
  muscles)
• Stereoscopic vision starts around 4-6 months,
  then develops rapidly

2
Visual cliff (Gibson and Walk, 1960)

• infants are not afraid of being over the glass
  until 7-8 months of age - onset of crawling

3
Visual cliff 2.

• Goats, chicks newborn
• Cats few weeks

4
Strabismus (squint, cross-eye)

• The two eyes are misaligned
• has to be treated early (before age 2 is the
  best)
• can cause loss of vision in one eye if not
  treated (amblyopia)

5
Face perception

• Are faces special among patterns? - yes, but the
  issue is still debated
• Face vs. scrambled face stimuli even neonates
  follow faces more
• However, it is not the same process as later face
  recognition subcortical -gt cortical switch

6
Face recognition

• Very early mother recognition (after 5 days),
  BUT based on crude features (hairline)

7
Molyneux's problem

• 17th century philosopher
• Suppose that a blind person who can distinguish
  spheres from cubes by touch suddenly becomes able
  to see. Will this person be able to distinguish
  these shapes visually before correlating sight
  and touch?
• 21th century cognitive science
• Corneal implants, cataract surgeries in adults
  vision can be recovered, but not entirely
• The difference between today and 2 years ago is
  that I can better guess at what I am seeing. What
  is the same is that I am still guessing. (MM, 43
  yrs, in Fine et al., 2003)

8
Cross-modal perception

• Demonstrates the existence of amodal
  representations

mom
Hi, darling!
hearing
from other room
vision
9
Cross-modal perception

• 1-month-old infants (!)
• Training sucking at one of the pacifiers
  (without seeing it)
• Test which one did infants spend more time
  looking at