(4) Perceptual & Sensorimotor Development Flashcards
What is Visual Acuity?
sharpness of vision; clarity that fine details can be detected
What type of vision do new borns have?
20/400 vision
What happens to visual acuity at 6 months?
acuity approximates normal adult vision
What happens to visual acuity at 8 months?
more interest in distant objects, tiny objects
What happens to visual acuity at 2-4 months?
see full colour spectrum
What colours do new borns prefer?
grey
What patterns do new borns prefer?
prefer patterns to plain stimuli
What is pattern perception like at 2 months?
prefer more complex patterns to simpler ones
What is sticky fixation?
difficulty disengaging visual attention away from one feature to focus on another, staring into space
What is visual scanning like at 1 month?
Focuses on edges
What is visual scanning like at 2 month?
Internal features, sticky fixation
What is visual scanning like at 6 months?
adult like scanning
What is the idea of Perceiving Parts vs Wholes (Cohen & Younger, 1983)?
-Not just edges and corners, but whole shape
What is perceiving parts and wholes like at 4 months?
see subjective contours
What is perceiving parts and wholes like at 12 months?
recognise incomplete line drawings (Rose et al, 1997)
What does Johnson et al 1991 believe about the nature of face perception?
new borns track faces more than other stimuli
What is argued about the nurture of face perception?
face tracking being inborn is bias as gives them much experience with faces
What happens to face perception between 2-4 months?
prefer more complex facial stimuli; prefer mother’s face; discriminate individual faces, even strangers
What happens to face perception between 5-12 months?
discriminate emotional expressions, positive to negative
Why might face perception be bias?
Exposure to faces from birth, held close to face (can be bias)
Are infants able to identify family members?
Able to recognise family members face – mothers face in a photograph
What is Kinetic cues (1 months)?
- motion parallax- nearby objects appear to move faster than distant ones
- Sensitive to these first, blink when something comes close to their face
What is Binocular cues (3-5 months)?
- disparity- brain perceives depth when combining slightly different angle from each eye
- Reaching for parents, toys, ability for reaching helps to teach them how far away something is
What is Pictorial cues (5-7 months)?
- interposition – an object that overlaps another appears nearer (Granrud & Yonas 1984)
- Linear perspective: parallel lines appear to converge in distance (Arterberry et al 1991)
- Relation between depth perception development and motor development?
What did Gibson and Walk (1960) conduct?
Compare depth perception in infants of different species, visual cliff
What did Gibson and Walk (1960) find?
- more crawling experience – more avoidance of cliff
- Need to learn from motor experience
- Babies come aware of depth, won’t crawl over an edge
- Not scared of heights, they learn from motor experience not to go over edges
Is hearing or sight more mature at birth?
hearing
What is Auditory threshold?
quietest sound can hear (Aslin et al 1998)
How do new borns respond to sound?
Turn head towards sound
How do 7 month olds respond to sound?
know when sounding object in dark is within reach
How do 2 year olds respond to sound?
adult-like
What did Trainor & Heinmiller, 1998 find?
New-born: prefer music to non-melodic sounds
How do 4-6 month olds respond to music?
prefer more common chords
How do 6 month olds respond to music?
distinguish Western vs non-Western music scales
What is Infant-directed speech (motherese)?
speaking with a higher pitch
What did DeCasper & Spence, 1986 find?
Familiar rhyme heard during last 6 weeks of pregnancy vs novel rhyme – tested baby listening to rhyme by their mother or stranger – prefer mother
What is taste like for a new born?
detect 4 main tastes from 2 hrs old (and prefer sweet) – adaptive as breast milk is sweet
What is taste like for a 4 month old?
prefer salty to plain – might be around the time they start being weaned
What can bitter tastes suggest?
Bitter tastes can suggest that it’s poisonous
What did Menella & Beauchamp, 1996 find?
Universal facial expression for pleasant (sweet) vs unpleasant (rotten/fishy) odours
What type of odours do new borns like?
New-borns prefer familiar odours (amniotic fluid, breast milk, perfume)
What areas are most sensitive to touch?
Face, hands and feet most sensitive
How many pain receptors does a new born have?
Pain, same number of pain receptors as adults
What is Object discrimination (Streri et al 2000) ?
capable of holding and feeling objects or keeping in contact
What is a reflex?
involuntary response to external stimulation (McGraw 1940)
What are essential reflexes?
rooting, sucking, swallowing and swimming
What are non essential reflexes?
moro (startle), gripping (palmar grasp), stepping and Babinski
What is SIDS/cot death?
Unexplained sudden death of infant less than 1 year, usually during sleep
When is SIDS most common?
2-4 months
What are common features of SIDS?
Low muscle tone, abnormal heart rate pattern, disturbances in their wake sleep pattern
