things i dont know
Developmental cascades
Change in one domain at one time are not separate from everything else
Downstream effects that affect other aspects of development down the line
Brain basics
Organized into 3 major sections (forebrain, midbrain, hindbrain)
Forebrain is where thinking happens
The cerebral cortex (forebrain) has 4 lobes, 2 hemispheres with distinct, but overlapping and connected, functions
Neurons are the primary functional unit in the brain
There are many technologies to indirectly non-invasively study the brain in infants and children
-fMRI- -stands for functional magnetic resonance
-detects blood flow via oxygen
-good spatial resolution
-bad temporal resolution
very sensitive to movement
-EEG- stands for electroencephalography
-records electrical activity from the scalp
-bad spatial resolution
-good temporal resolution
-works well on infants because it's not very sensitive to some movement
-NIRS or fNIRS- -(functional) Near-Infrared Spectroscopy
-detects blood flow and oxygen metabolism changes
-better temporal resolution than fMRI
-better spatial resolution than EEG
-more tolerant to some movement than fMRI
- Major processes contributing to brain changes in infancy:
Neurogenesis- Rapid growth of new neurons, made through mitosis
-begins during 3rd or 4th week of gestation
-occurring mostly between 3rd-18th week gestation
Neural migration- neurons move to their "proper" location in the brain, taking on specialized functions
Synaptogenesis--synapse is the small space between axons and dendrites that allow the flow of neurotransmitters between neurons
-creation of synapses, allowing the connection between neurons
-begins in the 2nd trimester, continues throughout life (to different degrees)
-surges in first 2-years of life and in adolescence
Myelination- -begins during 3rd trimester and continues into early adulthood
-happens for different parts of the brain at different times
-allows signals to travel down the axon quicker
-formation of the myelin sheath surrounding axons (only in some neurons)
synaptic pruning- synaptogenesis leads to hyperconnectivity
-neurons are connected that don't need to be connected
pruning removes those superfluous connections
if you don’t use it, you lose it
o Plasticity- -the brain changes and adapts due to experience
-some kinds of experience are expected and are necessary for typical developments to occur (called experience-expectant plasticity)
-the brain also adapts to a person's unique experience (called experience-dependent plasticity)
Dr. Romeo
Language input and ASD diagnosis in at risk children
Choices about who to include and exclude from a research sutdy
Dr. Kibbe
Infants’ memory of object features and categories
How to interpret looking time in a violation-of-expectation paradigm
Poyraz
TOM and inhibition
Using computational modeling as a tool for understanding cognitive development
JULIA LECTURE
Estimation task for children, before estimating, were told there’s two people with different estimations.
2 different conditions
Female over-estimate condition
Male over-estimate condition
There is an immediate effect of informant gender
Kids tend to trust the male informant more than the female informant
Approximate Number System
Mental system that you use to track numerical information without the use of symbols
Approximately knowing there’s _ many more dots than the number of dots next to it
Comparing 5 vs. 7 is harder than 5 vs. 10
Innate, born with the ability to represent numbers this way
Becomes more automatic and precise as we age
Lots of species have this ability
Theory-theory
A developmental theory that people have internal theories of how the world works
Determines predictions you will make about the world
Kids fail false belief tasks because their theory of the world does not include the idea that people can have false beliefs
Explanation for why children fail Theory of mind
Phonological development → learning speech sounds
Semantic development → learning word meaning
Syntactic development → putting words together
Pragmatic development → learning communication norms
Microgenetic Study- Intensive observations over short, frequent intervals
Phenotype- Observable traits resulting from genotype and environment
Genotype- Genetic makeup of an organism inherited from parents
Birth Stages-Contractions open cervix, propel fetus, expel placenta
Explaining language development- By 10-12 months, their ability to perceive other-language phonemes has decreased. Some mechanism that may support language learning:
Statistical learning
Figure out patterns/trends from data
Whole object bias
Syntactic bootstrapping
Mutual exclusivity
The expectation that an entity has only one name
Infant Perception Methods- Studying infants through sucking, looking, moving, reaching
Preferential Looking Paradigm- Infants' visual preference assessment method
Contingent Reinforcement- Reward delivery for desired behavior in infants
Executive function:
A collection of skills involved in controlling and coordinating attention, memory, and other behaviors involved in goal-directed actions
Inhibitory control
Cognitive flexibility
Working memory
Planning
Strategies for remembering
Self-monitoring
Cognitive flexibility- is the ability to adapt and switch between different tasks, rules, or strategies in response to changing demands or situations.
Perceptual Integration- Infants linking information from different senses
OAE-Measures inner ear responses in infants
ABR- Measures auditory nerve responses in infants
Prehension-Act of grasping or seizing objects using hands or body parts
Gesell scales- Established by Gesell to track infant motor development
Pincer grasp- Adapting hand shape to grip objects around 9 months
Habituation- stage 1:
repeatedly show a stimulus (or different stimuli that are similar in some way) until the baby looks less
premise: infants look less when they get bored, and they get bored when things are too familiar
used to measure:
-natural preferences
-change detection (discrimination)
-language comprehension
stage 2:
show something different and see what baby's looking is like
premise: if babies notice that it's different, their looking will rebound, because they'll be interested in this novel thing
contingent reinforcement-is a behaviorist term that refers to the delivery of a reward or reinforcement specifically when a desired behavior occurs
The infant's behavior controls the stimulus
It takes them some time to learn this, and then you can use it to look at natural preferences
Or, combine it with habituation to look at discrimination
- Vision
o Acuity: basic developmental timeline
to see fine detail with clarity and sharpness
Biological immaturity of the eye contribute to low visual acuity and contrast sensitivity at birth
Which improves over the first several months
< 6 months, infants have 20/591 vision
o Colors
2 months: see some colors•
4 months: see the full color range that adults can see
What about different color shades within a category?
Infants seem to perceive colors categorically by 4- months-old, using similar categories to those found in languages across the world!
o Size & Shape
We perceive objects to be the same size at different distances and angles, even though the actual image on our retina changes
Newborns seem to do this too!
o Object tracking
• First 2 months:
• jerky eye movements • slow tracking
• Between 2-5 months:
• Substantially smoother & faster
• Around 6-months:
• Anticipatory eye-movements: looking ahead of the actual stimulus
• E.g., moving your eyes to where an object will be, before it gets there
o Depth perception
- Depth perception is the ability to see the world in three dimensions and to perceive the distance of objects from oneself and from each other.
-Not present at birth
- By around 5 months, infants can perceive depth - but require
binocular cues, they cannot rely exclusively on monocular cues
By around 7 months, infants can use both monocular and binocular cues
o Face perception-
Infants' early experiences involve a lot of faces!
• But even newborns seem to prefer "normal" faces over distorted faces!
- Hearing
o Acuity: basic developmental timeline
Hearing begins to develop during the prenatal period
By around 36 weeks, sounds heard in utero are remembered after birth!
Still - hearing improves rapidly over the first year of life, but does not reach adultlike thresholds until much later in childhood
3-months-old:
must be as loud as a humming fridge
6-months-old:
must be as loud as a whisper
Adults:
must be as loud as rustling leaves
o Music and speech
• Infants seem to be predisposed to the features of music and speech
-And preferences & abilities become more culturally specific
over time
Speech: Neonates prefer speech vs. synthetic
sounds
They also prefer monkey vs. synthetic
AND no difference between monkey vs. human!
But by 3 months, they prefer human
o Perceptual integration
• When you perceive information from two sense simultaneously (intermodal perception), we sometimes link them together
• Infants seem to do this too, using synchrony as a cue