psychology
PSYA02: Introduction to Clinical, Developmental, Social, and Personality Psychology
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Human Development, Part 2
Infant and Child Development
Daily objectives
By the end of class today, you should be able to…
...define the term teratogen and give some examples of them and their effects on the developing human organism
...explain how preferential looking can be used to measure infants’ perception
...describe major patterns in motor development
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Teratogens
Not everything that the fetus experiences in utero is positive for its development
One of the most widespread causes of fetal abnormalities is the presence of teratogens—external agents that cause damage or death during prenatal development
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Teratogens
Teratogens most affect fetuses during a series of cascading sensitive periods
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Siegler et al., 2014
Fetal Alcohol Spectrum Disorder
The most common and preventable teratogen: alcohol
Enters the fetal blood stream
The most severe complication arising from ingestion of alcohol during pregnancy is Fetal Alcohol Spectrum Disorder (FASD).
Facial deformities
Intellectual disability
Attention disability
Behaviour disorders
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Birth
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Neonatal period
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The average neonate (newborn) spends the majority of the day sleeping
Neonatal sleep
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Crying
Neonates spend ~2 hours per day crying
Increases after birth until about 6 weeks
Most often non-communicative until they are older
But can also be due to hunger, discomfort, pain, overstimulation
Peaks in late afternoon and evening
All infants go through a period of increased crying between birth and 6 weeks
But some infants cry more than others (“colic”)
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Perceptual development
Review: perceptual development begins in utero
But the perceptual experiences beginning after birth are much richer
Sensation = sensory organs’ detection of physical signals in the environment
Perception = organization and interpretation of the sensory information into coherent understanding of objects, individuals, events
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Measuring infants’ perception
When you visit the optometrist, how does he/she measure your visual acuity and colour vision?
Verbal report
How is it that we know what infants are able to see?
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Preferential looking
How is it that we know what infants are able to see?
One of the most powerful methods that we have available is preferential looking
Infants, like adults, choose to spend more of their time looking at objects and events that are interesting, stimulating, or familiar
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Visual acuity
For example, we can use preferential looking to determine infants’ visual acuity
1-month-old infants prefer to look at patterned images over grey images
However, when the lines in the pattern are close together, infants do not show a preference over patterns versus grey
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Visual acuity
In their first month of life, infants’ visual acuity is approximately equal to 20/120
This acuity is equivalent to being able to decipher only the top line of a visual acuity test plate
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Motor development in infancy
Newborns’ motor skills consist predominantly of reflexes
Grasping
Rooting
Sucking
Swallowing
Tonic neck reflex
…some of which last for the entire lifespan:
Coughing
Sneezing
Blinking
Withdrawal from pain
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Tonic neck reflex—arm extends on the same side as head is turned, maybe so that infants can see their own hand easily
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Motor development in infancy
After reflexes, the development of sophisticated motor behaviours follows two rules:
Cephalocaudal rule: ‘Top-to-bottom’ rule that describes the tendency for motor skills to emerge in sequence from the head to the feet
Proximodistal rule: ‘Inside-to-outside’ rule that describes the tendency for motor skills to emerge in sequence from the center to the periphery
Motor development
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Motor development Visual development
Motor development also has a clear effect on visual development
Walking more visual information than crawling
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Karen Adolph
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Karen Adolph
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Lavf56.40.101