Lecture 2- Perceptual Development in Infancy Flashcards
What ages are infancy?
0-2
Define Reflexes
- purpose, reveal?****
Automatic responses triggered by specific, relatively localised stimuli
- innate (unlearned)
- automatic
- survival function (crying = protection)
- Basis for further development
- Reveal the health of the nervous system - if reflexes arent there, they may not have healthy neuro pathways
When does the eye blink reflex dissapear?
Never
Outline the rooting reflex, and when it disappears
****
- stroking cheek, baby turns head getting ready to feed
- evolutionary function - nipple means they feed straight after
- Stops after 3 weeks - important for early feeding
When does the sucking reflex dissappear?
Never
When does the swimming reflex dissappear? ***
4-6 months
Outline the moro reflex and when it disappears**
- Startle reflex, fling arms out wide
- Survival function - trying to grab parents
- 6months
When does the palmar grap reflex disappear?**
3-4 months
- good for building relationships
Outline the tonic neck reflex and when it disappears**
WHen head faces certain way, the arm and leg on that side extend - look like a fencer
- 4 months
Outline the stepping reflex and when it disapears**
helps future skills
- 2 months
Outline the babinski reflex and when it disapears
Toes fan out then curl after bottom of feet is stroked
- 8-12 months
Outline all the reflexes - there are 9
*****
- Eye blink -permanent
- Rooting - 3 weeks
- Sucking - permanent
- Swimming - 4-6 months
- Moro - 6 months
- Palmar Grasp - 3-4 months
- Tonic Neck - 4 months
- Stepping - 2 months
- Babinski - 8-12 months
If reflexes are still present when they should have gone, what does it show?
Development delays and problems - e.g. may have cerebral palsy
What are the 5 methods of studying infants?****
They cant talk, so how can we study their perception? •Looking •Reaching • Turning • sucking • facial expression
What are limitations of studying infants? 5 things ****
X - may get upset X - may fall asleep X - can only infer, dont know for sure X - no consent X - Easily distracted
Outline Fantz (1958) Preferential Looking chamber
- Tests where an infant is looking and for how long
- Uses eye tracking
- Systematically swap each side to avoid bias
- infants fixate on familiar stimuli
- and stimuli with multiple sense that match
Outline the habituation method
Show them an image/ stimuli until they get bored
- then show them a second image
- if they think it is the same, the wont start at it
- but if it is new they will stare at it longer
Outline Event related potentials as a method of studying infants*****
- Monitor brainwaves to see if they discriminate 2 items
- If they perceive the two things as different, the brain waves will be different
Outline High Amplitude sucking
- DeCasper and Fifer (1980)
DeCasper and Fifer (1980)
- Show two images, each one stays up as long as they are sucking, They suck harder and faster if they like something, to keep it on screen longer
When can babies imitate?
From birth (Meltzoff & Moore, 1977 - its quite advanced, as they need to be able to remeber and produce the gestures
Outline Taste perceptions in new borns
*****
They have 4 basic tastes: Sweet, sour, bitter, salty
- cannot discriminate salt until 4 months - dangerous
- prefer sweet - e.g. breast milk
- Neophobia - fear of consuming new foods
When do taste buds develop in the gestation in the womb?
7-8 weeks - except salt
When does exposure to flavours first occur
- Manella et al (2001) - carrot juice
in the womb
- when mother drank loads of carrot juice whilst pregnant, the infant showed a preference for it when born (Manella, Jagnow & Deauchamp, 2001)
- mothers diet is very influential, including how breast milk tastes
Outline Steiner’s research into flavour perceptions
- waters
Different tasting waters produced different facial responses
Outline Smell perception in new borns
- Linked to taste
- can detect nice and bad smells
- recognise mothers smell at 4 days, like it the most
- Prefer smell of lactating women to non-lactacting (evolutionary), prefer smell of mothers milk the most
- prefer smell of breast millk over formula milk
Outline touch perception in new borns
** tempeature (Pratt)
- Sensitive to temperature (Pratt, 1954) - recognise changes
- Questions about if newborns can feel pain - and at which point this comes about - they can yes
• because of their distress at injections - Soothing - relationship with mum is soothing
- Explore the world with touch - helps them learn
Outline sight perception in new borns
Worst sense at birth - as they never used it in the womb
- Very blurry acuity - but by 1 year, its adult levels
•Optimal is 20/20, they have 20/400-800
- Can track slow objects
- See colour, but not the best at distinguishing
- Rapid development at 2 months
- first place to start social interaction but
Outline Depth Perception in new borns
- cues involved
Depth perception involves
- kinetic cues (3 months) - moving of head changes perception
- Binocular cues (4 months) - more similar the objects = closer it is
- Pictorial cues (5-7 months) - cues in the picture
Show understanding of looming - if heart rate goes up as objects get closer, shows they understand thi
Visual cliff - Gibson & Walk (1960)
- by 6.5 months, 90% wont cross
Outline Gibson & Walks Visual Cliff (1960)
36, infants, 6-14 months
mothers stood across the chasm and encouraged them
- they would crawl over the shallow side fine, but very few would across the deep end
- by 6.5 months, 90% wont cross
Outline preference for faces - types of faces they prefer
Infants have a preferences for:
•Human faces (Fantz, 1961)
•Mothers face (Walton et al 1992)
•Attractive faces
Outline Fantz (1961) - preference for Human faces
- faces were either normal, jumbled facial features,
or control with same overall brightness (so top 3rd was dark for the hair, other 2/3’s were light) - they had a preference for the actual looking faces
Outline Walton et al 1992 - preference for mothers faces
**
- Survival/ forming bond
- Have a preference for mother a few hours after birth
- we know this from high amplitude sucking experiments
What are the two ideas about why we have a preference for faces?
*****
- Imprinting - first thing we see after birth, and mothers is first one?
- Innate - evolution
What can babies hear pre-birth?
DeCasper & Spence (1986) - pregnant mothers read aloud passages, including cat in the hat
- infants recognised these more than new pasages they had never heard before. They tested this through high amplitude sucking
What can infants hear in terms of pitch
- high pitch is quieter but they prefer it!
What can infants judge about location?*****
Can judge general location
- turn heads towards it
Outline infants auditory perception****
- By 1 month, can distinsuihed speech sounds ‘pa’ and ‘ba’ (Eiams, 1975, 1985)
- synaptic pruning - keeping sounds in their language
- Individual voices - recognise mums voice (DeCasper & Spence), but not their fathers
- Can match face and voice at 6 months
- Can discriminate categories of songs - e.g. lullabys
Outline the problem of inter-modal perception***
- pickman - train
We receive all sense at the same time, so can infants integrate information from all sensory streams and create a whole?
- can they transfer information across the sense
- e.g. which mouth movements need to be done to get the sound you want to make
- can detect one modality from birth, but senses involve multiple
- pickmans - infants looked at a photo of train more if the sound being played was of a train
Outline sensory processing disorder**
- problems with sensory processing
- problems integrating information
- leads to clumsy movements, difficulties learning/ processing new information
- symptoms: not wanting lots of pressure on them, or needing lots of pressure for them to notice
Outline the 2 contrasting theories of infants perceptual abilities/ integration***
Enrichment theory (Piaget, 1952/ 1954) Differentiation theory (Gibson and Gibson, 1955)
Outline Enrichment theory
- INNATE SChemas that develop through interaction with the world
- active and exploratory
Piaget (1952/1954)
- critical period for perceptual abilities = sensori-motor stage (0-2)
- skills arent present at birth, but develop over the first year
- as a result of interacting with the environment - performing operations and seeing the results
- sophistication in perceptual skills will develop over several stages
- in this period, they learn to co-ordinate sensory input and motor behaviour
- They use schemas to do this - rely on innate sensori-motor schemas - grasping/ touching (exploratory), to get information about the world
- Use schemas we have to test our knowledge
- schemas allow information integration
Limitations of Enrichment theory?**
X - Overestimates things - Even those really good at crawling dont have any difference in depth perception - they have good motor and movement skills but no differences in depth
Outline Differentiation theory
- We learn through finding out differences in the world around us
Gibson and Gibson (1955)
- Integration of senses possible from birth
- Development depends on interaction
- We learn through seeing differences between objects
- identify what makes things different, thats how we learn about perceptual development
- Initially you overgeneralise - see things as the same, cant tell them apart.
- AS you grow, you can make distinctions between objects and events
- Exposure to these events/ objects allows you to identify the properties that make things different
- its not about the objects meanings, its just telling them apart
Outline experimental evidence for Differentiation theory
- Sight/ Sound research (Rosenbloom, 1971)*****
- Sight/ touch research - dummy
Aronson & Rosenbloom (1971) (Sight/ sound)
- 1 months old were sat behind a sound proof screen, could see their mother
- more distressed when the voice didnt come from where the mother was.
- they expect voices to come from the face as they have integrated
Sight/ touch research
- had to touch the dummy that looked like the one they were currently sucking
