Preference Technique
*showed infants 2 diff stimuli and if they looked at one longer than another, it expressed knowledge of difference and preference
Habituation
- present baby with stimulus over and over until no longer interest and then present with novel stimulus
- if baby interested again, it can tell difference bw the 2 stimuli
Operant Conditioning
- train baby to make a response to some sort of stimulus
* offer reward every time they do proper response
Vision
- deferentially developed - doesn’t have to see in womb
* develops to extent of forming emotional attachment to parent and nothing more
Hearing
- partially developed as they can hear rumbling
* hear sounds in environment but don’t have to know what it is
Taste
- most developed as they can taste amniotic fluid
* survival value- can tell diff bw bitter and sweet
Visual Acuity
- 20/300 at birth, 20/120 at 1 month, 20/60 at 4 months, 20/30 at 8 months, 20/20 at 2 yrs
- tracking- watching moving object; not that good at birth but develops rapidly
Auditory Acuity
*can hear everything expect very high frequency (not developed prenatally, takes longer to develop)
Locating sounds
- avoid unwanted objects if we can hear where they are
- infants need ~27 degrees from mid line to differentiate which direction sound is from
- 6 months need ~12 degrees
- 18 months are adult-like with 4 degrees
Steiner
*proved that babies can tell difference bw 4 basic tastes- sweet, sour, salty, bitter
Kinetic Cues
2 months
- optical expansion
* motion parallax
Binocular cues (4 months)
- Retinal disparity
* convergence
Pictoral Cues (7-8 months)
- parallel lines
- interposition
- relative size
Visual Cliff
*tested with babies old enough to crawl
Face Preference
- babies prefer faces over other complex stimuli
* preferred proper faces over scrambled
Johnson Face Preference
- preference for proper face would lead to more head rotation
- heads rotated more when looking at proper face>scrambled>blobs
Walton Specific Faces
*babies preferred mom’s face over very similar looking mom
Langlois Specific Faces
- babies prefer attractive faces over unattractive faces
- att/att- same amount time looking
- unatt/unatt- same amount time looking
- att/unatt - more time looking at att face over unatt.
Social Cues
- babies can perceive social cues - know what facial expressions mean, prefer human faces over dolls, gaze following
- visual cliff- babies unsure about crossing look to moms face to read social cues/emotion to see if OK to cross
