Lecture 3 Flashcards
What is sensation?
Info gathering, senses
What is perception?
interpretation of sensory info
What is the nativism/ empiricism “debate”?
Nativism: babies born with abilities
Empiricism: babies use experience to develop adult like abilities
What are the techniques used to study babies?
1) Preference Technique
2) Habituation/ dishabituation technique
3) Operant conditioning technique
Preference Techniques
o Fantz chamber:Crib with glass walls, different images on either side. Watch to see which image is looked at more. If the baby chooses one over the other this indicates they can tell the difference between them.
Habituation/ Dishabituation Technique
Show same stimulus over and over again until the baby grows habituated. Present either the same or a different stimulus
If the baby recognizes the stimulus as different they will dishabituation
Operant Conditioning Technique
Condition infant to respond in a certain way by giving an award for certain behaviour.
Why might different senses be more or less developed at birth?
Experience
- hearing is better than vision
Survival Value
- taste and smell is good because its adaptive
What is babies visual acuity
- Newborn babies visual acuity is b/w 20/200 and 20/400
- Age 1 month 20/120
- Age 4 months 20/60
- By age 8 months they can see 20/30
- By age 2 they are at 20/20
When does babies ability to track develop?
Not bad at 6 weeks and almost perfect by 10 wks
How is babies auditory acuity?
oVery good at birth.
o have trouble with is high pitch tones.Not exposed to many of these prenatally
How are babies at locating sounds at:
2 mths?
6 mths?
18 mths?
2 mths- 27dgrs off midline
6 mths- 12 dgrs off midline
18 mths- 4 dgrs/ adult like
Describe how Steiner tested taste and what he found:
Moms to handed over newborn babies before they had eaten
•Placed in the baby’s mouth a water solution that had each of the tastes
oSweet- enjoyed
oSour- same sour face adults make
oBitter- dislike
• Taste is very well developed at birth
What are the types of cues used for depth perception?
- Pictoral (monocular cues)
- Binocular cues
- Kinetic cues
Which type of depth cues develop first?
Kinetic b/w one and 3 mths of age
Which type of depth cues develop last?
Pictoral b/w 6 or 7 mths of age
What are pictoral cues?
Use only one eye to judge the depth of object. Static, picture cues.
What are Binocular cues?
Using both eyes to look at an image, slightly different images in each eye. The closer you are to the object the more different the images will be.
Examples of pictoral cues:
Linear cues – train tracks disappearing into the distance
Interposition – The overlapping stuff is in front
Relative size – The biggest is the closest the smallest the the farthest away
What are kinetic cues
Associated with movement of an object
-Motion Paralax – as object move past us those closest to us move faster than those that are farther away from us
When do binocular cues develop?
Around 4 mths
How do we test development of kinetic cues?
• Bring an object towards the baby as if it is going to hit them in the head and see how babies react
Describe the visual cliff
- Glass table with checkered cloth directly under glass on one side (safe side) and way below the glass in a drop on the other side (the dangerous side)
- Test to see whether the baby is willing to go onto the dangerous end
How many of the 27 babies that left the plank went onto the dangerous side purposely ?
3
-correlation with the more crawling experience a baby has the more likely the baby is not to cross over the cliff
How old must the baby be to be tested on the visual cliff
approx 6 mths (crawling)
What other animals were tested on the visual cliff?
- 1 day old goat
- 4 wk old kittens
- 3 wk old rats
What was found in the non-human tests of the visual cliff?
If vision was primary modality would not go to deep side. In rats they use feel, so if their wiskers couldn’t touch wouldn’t cross
HR speeds up if you are . . .
scared
HR slows down if you are . . .
interested
How can you test babies that can’t move?
Heart rate
What were the heart rate results of babies from age 2 months to 8 months on the visual cliff?
Over 6 mths- HR sped up, scared
Under 6 mths- HR slowed dwn, interested
Require experience moving around
Do babies prefer faces?
Yes-
Describe Fantz’s experiment proving babies are biologically prepared to recognize faces:
Put babies between 4 days to 6 months of age into his fantz chamber and presented them with three stimuli
• Face
• Complex image that had equal black as face
• Blob face not complex but also equal black
Babies preferred the face then complex image then blob face
What age did Fantz’s face, fantz chamber experiment not work with? What was the solution?
Under three months were not consistent. Solution was a less complex task. Eye following of preferred stimuli with indicated preference for face followed by complex face like followed by blob
Do babies prefer all faces? Or some faces to other faces?
- Newborn babies prefer mom’s face to a face that is very similar but is a stranger
- Large preference for attractive faces (as rated by adults) at 2-7 mths of age
- One year olds prefer to play with attractive adults
Can Babies Perceive Social Cues?
Basic developmental pattern of being able to recognize facial and vocal expression
By what age do babies show a preference for human faces over doll faces?
Age 2-3 months, also interested in interacting with humans but not dolls
By what age do babies react to different emotions? How was this tested?
10 weeks, This was tested by training moms to make facial expressions.
How did babies react to mom’s different facial expressions?
Happiness – Babies would engage
Sadness –The babies will look away from mom did not want to engage with this face
Anger – Babies would cry or freeze
What 2 social cues can babies age 7-8 mths tell the diference between?
Happy and sad voices,
they also follow the gaze of the person they’re interacting with
What are Ekman’s basic faces?
Angry, Sad, Scared, Surprised, Happy, Disgusted
Describe the babies social referencing behaviour on the visual cliff:
Babies interpreted moms expression to decide how to react.
How did Sorce et al test social referencing of one year olds on the visual cliff?
- Used a visual cliff but they put the cliff at one foot deep, a depth that is very confusing to babies.
- Get mom to call baby to the dangerous side
- When baby gets to the cliff they will get confused and look at mom
- Mom will make a face at baby: Happy, fearful, interested, angry or sad.
Can babies engage in social referencing?
Yes
visual cliff: How did babies react if moms face was happy?
-Happy – 75% cross
visual cliff: How did babies react if moms face was interested?
-Interested – 75% cross
visual cliff: How did babies react if moms face was fearful?
Fearful – None cross
visual cliff: How did babies react if moms face was angry?
Angry – 10% cross (significantly lower than 50% crossed)
visual cliff: How did babies react if moms face was sad?
-Sad – 30% cross
Did babies use social referencing if the cliff was safe?
No, If a safe cliff
- Only 20% of babies looked at mom and moms face had no influence on these babies
Why do babies sensory abilities range from adult like to poor?
Adaptiveness of being able to use some abilities before others
Why are depth and face perception really good?
Evolutionary useful skills for survival
How is it beneficial that babies can “read” others emotions?
Evolutionary explanation, it’s good to know if someone will be rewarding or not
Was Johnson’s or Fantz’s method better for testing young babies?
Johnson’s method of watching how long babies follow a stimuli.
