developmental psych exam 2

• perceptual narrowing (tuning)


  infants form a species specific face template by 9 months

  • better at identifying specific faces over first weeks
  • develop an abstract representation, then compare specific faces to that prototype
• auditory localization


  crude ability to detect where sound is being heard'
• intermodal perception


  using multiple senses at once

  ie sight and hearing to determine where an object is heard

  for babies: sight and touch in the mouth

  • 1 month old sucks on pacifier but can't see it
• mcgurk effect


  mind tries to put together what you hear and what you see the mouth say
• rooting reflex


  newborn's mouth moves toward touch on cheek when hungry
• sucking reflex


  oral contact with nipple, sucking starts
• grasp reflex


  newborns grab on to anything in their hand
• stepping reflex


  baby will step when lowered on surface
• affordances


  possibilities for action offered, or afforded, by objects and situations

  ie babies discover that small objects afford the possibility of being picked up. infants discover affordances by figuring out the relations between their own bodies and abilities and the things around them
• reaching


  one infants can reach for and grasp objects, they no longer have to wait for the world to come to them
• pre-reaching movements


  clumsy swiping in the general vicinity of objects

  3-4 months: successfully reach for objects, although movements are somewhat jerky and poorly controlled, grabs fail more often than not
• self-locomotion


  8 months of age; capable of moving around in the environment on their own

  • alters other aspects of infants' perceptual experience
• Perceptual Development


  The development of how infants perceive and make sense of the world around them
• Early face preferences


  • Some evidence that newborns expect to see faces
  • Faces are objects that have a specific organization
  • Newborns prefer normal face schematic
  • By 3 months, this preference disappears
  • Preference guides babies to faces as early input
• Face recognition beyond human faces

  1. Paired-comparison procedure (VPC) used

  2. Assess recognition in both infants and adults

  3. VPC indexes relative interest in novel vs familiar stimuli

  4. Recognition inferred from tendency to fixate novel item

  
• Perceptual Narrowing (Tuning)


  Infants form a species specific, face template by 9 months
• By 9 months infants form species prototype, compare specific faces to the prototype
• Infants attend to speech that is likely to be relevant to them, like motherese and music/language patterns from their own culture
• 1. month-olds interpret speech intonations, differentiate approval from disapproval
• Auditory Localization


  1. Crude ability in newborns - use sound intensity, turn head toward sound

  2. By 4-months, will orient again, but now better at it

  3. Will reach toward sound - believe there is something "out there"
• Experiments with owls show sensitive period, improved sound localization if deprived of vision, but must be young enough

  
• Intermodal Perception


  Senses are not completely independent, sight and touch can interact
• The McGurk Effect demonstrates how the mind tries to put together what you hear and what you see the mouth say, infants experience this illusion by 4.5 months
• Infants have several innate abilities for perception, but these are typically shaped by experience and the environment
• Developmental trajectories differ across the senses, sometimes causing steady improvement in skill, and sometimes requiring narrowing of abilities (perceptual tuning)
• Motor Development


  • Learning to crawl - 3 months
  • Learning to walk - 10 months

  
• Why is walking so hard?

  Requires integration of brain, anatomy and experience
• Motor Milestones


  • Rolling over
  • Pressing up with arms
  • Rooting reflex
  • Sucking reflex
  • Grasp reflex
  • Stepping reflex
• Reflexes


  Born with reflexes that start to disappear at about 2 months, then re-appear later in a U-shaped curve
• Disappearing reflexes like stepping reflex are due to growth of limbs making them harder to perform, not just brain maturation
• Water test shows reflexes never really go away, just harder to perform as limbs get heavier
• Cultural practices like Hopi cradleboards and Ache nomads carrying infants affect motor development, but no long-term problems
• Racist interpretations of differences in walking timing between cultures are completely ignoring the role of cultural practices
• Integrating perception and motor experience


  Walking requires judging distances, depths, affordances, and integrating visual and motor information
• Kitten experiments on visual flow fields

  Passive kittens showed deficits, motor activity needs to be paired with visual input for typical visual-motor integration
• Blind children delayed in walking but not crawling, as they lack the visual flow field information used by sighted infants
• Experience with reaching, like "sticky mittens", can accelerate motor development in infants
• Scale errors occur when children are too excited to properly judge the mismatch between size of object and self
• Motor development depends on the integration of maturation (brain and physical growth) with experience (visual and physical)
• Perceptual narrowing for faces

  1. month-olds can identify individual human & monkey faces, but 9-month-olds and adults are not nearly as good. This is because babies form a species-specific face template by 9 months, so they get better at identifying human faces but all monkey faces start to look the same.