Lesson 7 - Sensory Development Flashcards
How is a baseline sucking rate established?
Infants are given a dummy to suck and they are given a stimulus to see if the sucking rate changes
Sucking more = ?
Infant is excited
No change in sucking rate = ?
Not noticed anything different
What must be done before observing the change in sucking from babies of their dummy?
Establish a baseline sucking rate
What does a change in sucking rate mean?
infant is able to see a difference between 3 items and 5 items
Infants are shown a picture until they habituate
Habituate means
fed up / used to / get bored of it
A decrease in response to a stimulus after repeated presentations
we measure how much they look at the new picture
How can we figure out whether infants can tell that two things are different / whether they can remember the first picture?
Thru the proportion of time spent looking at the new picture
What is the Visual Paired Comparison Task?
If infants can distinguish between unfamiliar and familiar stimuli then they should look at each other different amounts
Method relies on habituation
HOW COULD WE ASSESS MEMORY IN CHILDREN DURING THE FIRST YEAR OF LIFE?
First - we know what infants cant do - but we need to figure out what they can do
Identify basic behaviours infants can reliably create
For observations there’s a starting point - do those behaviours change when aspects of the child’s environment change
How long does it take for vision to develop?
Around 1 year basic perceptual aspects of the human visual system to fully develop
The neural parts of the visual system develop during gestation
Though its not until birth that visual stimuli are perceived
When are the neural parts of the visual system developed?
During gestation
What can newborn infants see?
Although dim and fuzzy, they can see light, shapes and movement
not capable of fixation)
range of vision approx 30cm
What do 1-2 month old babies see?
Infants can fixate objects
Can distinguish between high contrast colours
eg black and white
What can 4 month old babies see?
Depth perception improves
Colour vision better
Infants can now follow objects with their eyes (ie without having to turn their head)
What can 8 month old babies see?
The range of effective vision increases
Infants can now recognise people from across a room
What can 1 year olds see?
Basic visual skills are broadly similar at adult levels
From birth, what can babies see in faces?
From birth, infants show a prefer interest in face- like stimuli
Even within a day of birth, newborns are capable of recognising individual faces
Visual recognition in newborns is unlikely to be accompanied by any explicit cognitive insight
Though early perception will form the basis for later mental representations
Newborn infant’s ability to recognise their mother’s face persists even when olfactory cues are removed and when inadvertent visual cues are controlled for
This is noteworthy given that infants’ visual acuity is relatively poor
What did Fantz find?
- Fantz’s 1961 study showed a series of stimuli to young infants, and observed their looking behaviour
Fantz’s - from birth, infants showed a small but consistent preference for the face-like configuration
The same pattern is seen when presenting moving images to newborns - they follow face-like stimuli for longer (Goren et al 1975)
Perceptual narrowing with faces?
With experience, infants’ visual perception gets increasingly attuned to regular features of the child’s environment
Very general abilities are more finely tuned following experience - this is particularly seen with facial recognition
What is The “Other Race” Effect ?
^ The tendency to more easily recognise faces of the race one is most familiar with - Kelly et al 2007
- Infants are initially able to discriminate pretty well between the faces they see
- They gradually become extremely good at distinguishing between the kinds of faces they see around them
- While gradually losing their abilities to discriminate between faces that they dont see often, or at all - Kelly et al 2007
- However, it is possible to retain the ability to distinguish between unfamiliar face types, by shaping the infant’s experience
- This has been shown through studies where parents read picture books to their infants (Heron-Delaney et al 2001)
Perceptual narrowing with faces
6 month old Caucasian children were able to discriminate same and other race faces
9 month old caucasian babies shown a book with caucasian faces lost the ability to recognise chinese faces
9 month old caucasian babies shown a book with chinese faces retained the ability to recognise chinese faces
Face processing abilities are shaped by experience
This isnt unique to human faces
Book- training studies show infants can retain the ability to recognise individuals from other species (Pascalis et al 2005)
When can sound be perceived in the womb?
Unlike vision, sound can be perceived in the womb prior to birth
Hearing language
IDS isn’t a completely different way of speaking - its an exaggeration of existing patterns of speech in the language
Its thought to help infants to extract smaller chunks of language
IDS is an important first step in infants learning language
Perceptual narrowing hearing
Infants gradually exchange their vast potential for processing all types of information in return for a swifter, greater expertise in processing the information they see most often in their environment
Infants show a preference for Infant-Directed Speech, rather than typical adult-like speech (Cooper and Aslin 1990)
They pay more attention to speech when it has a higher and wider pitch range
a common way of adapting your speech to have an exaggerated pitch, range and speech (also known as Motherese)
How does hearing particularly speech perception become more specialised with age?
Infants are initially able to distinguish between phonemes that dont occur in their native language (Trehub 1976)
This ability narrows to sounds contained in their own language (Eimas et al 1971)
From 26 weeks, what do foetuses show?
From 26 weeks, foetuses show changes in heart rate as a direct response to auditory stimuli
Full term foetuses can recognise what?
Mothers voice
How much auditory information do babies pick up in the womb?
Newborn infants preferred hearing the story read while they were in the womb
This was true even when stories were read by a stranger, and not the child’s mother
Babies not exposed to these stories while in the womb showed no preference
Understanding speech is a remarkably complex process requiring that we segment a continuous stream of sound into separate parts
