Developmental Lecture One - Babies Flashcards
Describe research methods used to examine young babies’ perception: preferential looking and habituation paradigms
Preferential looking
One screen – woman smiling
Second screen – same woman not smiling
- Secret experimenter/camera, paying attention to where the baby is looking, time how long the baby is looking and where.
- Have to use multiple babies as one baby may be tired, look for averages, average looking time, may find there are particular patterns in things babies prefer to look at. Means they are able to tell the difference if multiple babies look at the same thing for longer, innate perception.
Habituation/dishabituation paradigms
- Habituation – a behaviour/capacity demonstrated by all organisms e.g. adults, babies etc. The process where we can stop responding to certain stimuli if it doesn’t seem relevant for our environment. E.g. sounds around us that we are responding to but not receding them unless we make the effort as we have habituated to these sounds (blocked them out). Happens at a neural level, over time, repeated stimuli, biologically overtime nonresponses reduce to that, fading out that which is not relevant to us in our environment.
- Ongoing stimuli causes habituation, decreased response, evidence of learning/memory.
- Habituation – pretty much how we are all of the time.
Response (baby’s response) to novel stimuli:
- Turns head.
- Heart-beat slows. Slowing down their heart as blood has been directed to other parts of their body – trying to perceive the new stimuli, this is dishabituation.
- Suck patterns change.
- Become consciously aware or focus on something that is new.
- Change in ongoing stimuli causes dishabituation.
- Can use dishabituation to discriminate between different colours. E.g. give babies the same toy in different colours and see how they react (heartrate monitor etc), could use different shades, use different colours to show how much they differentiate between two colours.
- Could show a baby two colours very similar and then two colours very different and monitor the eye movement.
IF SOMEONE HAS HABITUATED SOMETHING IT SHOWS THEY HAVE GOT USED TO IT (used to the ongoing stimuli, therefore stop perceiving it), IF THEY DISHABITUATE SMETHING, IT SHOWS THEY HAVE SEEN A DIFFERENCE (consciously attend to a new stimuli, e.g. something sets on fire, you go and pay attention to it), adjusting to it.
- Humans pain receptors cannot habituate, you don’t get used to pain, you always perceive it.
- So habituate is when you’re used to the stimuli and you don’t get fascinated by it anymore which is then dishabituation.
Describe peri- and neo-natal human perception abitlities in terms of auditory perception, facial recognition and early conceptual development:
Auditory perception before birth (perinatal):
-Habituation/dishabituation observable in utero, (can measure heart rate in utero).
-Recognition of mothers voice – Kisilevsky et al (2003): more marked dishabituation to recording of mother reading. More drop in heart rate when they hear someone else reading than when their mother reads – used to their mother.
-DeCasper & Spence (1986): newborns will “choose” to listen to familiar language. Two different stories – before birth babies first heard a particular story, something like once a day for six weeks. In neutro – trained to do HAS, then given a choice to either hear the same story read by a stranger or a completely different story read by the same stranger – more prone to selecting the familiar story by the stranger. Shows they recognise not just the voice but particular patterns of language.
HAS – High amplitude suck technique – in neutro – after a baby is born, you can train them - if they suck at one speed they hear one thing, if they suck at a different speed they hear another thing.
Visual perception after birth (neo-natal):
- Facial recognition/perception:
- General bias towards patterns with more elements in the upper half (Macchi Cassia et al, 2004). E.g. eyebrows, eyes, ears, down is just mouth.
- Preference for caregiver’s face within first few days of life (Bushnell et al, 2011).
- Moving into habituation/dishabituation – discrimination of faces becomes specialised to human faces over time
- These studies often use preferential looking.
- Babies can tell two monkey faces apart just as well as they can tell human faces apart.
Perception/conceptual development
-Use of violation of expectation paradigms. CARROT. This displays to the baby something that is not in line with everyday expectations about the physical world. Based on habituation/dishabituation.
-Baby may dishabituate slightly if they see the new shape. Will get bored of the first image after a while, the new shape gives a bit of dishabituation, heart rate raises again.
Expecting to see a load of green hair go through the gap but they don’t. Showing more dishabituation, as it seems more interesting as they are confused/trying to figure out how/why there is no hair through the gap.
Perception/conceptual development
Use of violation of expectation paradigms
-Based on habituation/dishabituation.
-Enables infants to demonstrate understanding of key properties of objects e.g.:
-solidity: two objects cannot occupy the same space at the same time.
-support: unsupported objects fall
-shape and size constancy: objects remain the same although they change their appearance dependent from the distance from the observer/angle at which the object is.
From about six months babies are showing lots and lots of interest in the physical world and the properties of objects within it, we know this as they are paying attention to things happening to things that will violate those conditions otherwise.
Define functional and vestigial motor reflexes, and provide examples of each of these:
Developmental milestones: motor skills
- Simple reflexes (present at birth and almost certainly innate) e.g. you blink when someone’s hand comes towards you (the stimuli triggering a movement).
- Babies are born with these, these include (but are not limited to) primitive (infantile) reflexes that tend to gradually disappear over time. There are 2 categories, 1. Functional infantile reflexes and 2, Vestigial infantile reflexes.
- Functional reflex – babies sucking reflex, reflexes that even though they are unintentional they are beneficial for survival.
- Vestigial reflexes – reflexes that don’t have any clear benefit for the baby, use of significance biologically that right now aren’t doing much for us but at some point did. E.g. beards, ancestors having hair made more sense.
- By dropping the babies head when holding it triggers Moro reflex, the babies arms go out and back in and then they cry, e.g. we may have had an ancestor that was really hairy, grabbing the hair when dropping the baby would stop it from falling to the floor.
- Gaining control over body movements: follows cephalocaudal and proximodistal trends.
- Babies gradually gain contorl over the bodies, headfirst, down to toe = cephalocaudal.
- Head down and middle out is the way motor skills move.
- Proximodistal – from the trunk and then out.
- First gaining control of the body of things that are most essential for survival, e.g. brain, middle of our bodies to enable movement.
