Quiz 1 Flashcards
What does it mean to be a child?
- Dependent on adult caregiver (longest childhood among primates. Born earlier because large heads)
- Fundamentally about learning (children are adapted to learning because they are: curious, suggestible, like to imitate others, overestimate own abilities, malleable brains)
Children can only focus on learning if cared by an adult
Child development
Process of learning of perceptual, cognitive, emotional, and social capabilities that allows an individual to grow from the dependence of infancy to the independence of adulthood
What do babies see?
From birth, babies can visually scan an environment and pause to look at stuff
Methods in infant research
- Preferential looking paradigm
- Habituation paradigm
Preferential looking paradigm
- Present the baby with 2 stimuli
- If the baby looks at one longer than the other it means that they can distinguish a difference + they like that one better
- Babies prefer things that are colourful, more complex, familiar
Habituation Paradigm
Takes advantage of babies’ preference for novelty
- Habituation phase: repeatedly present infant with stimulus until used to it
- Test: present old with new stimulus and see if they look at the new one more (called Dishabituation)
Familiarity vs Novelty
Prefer familiarity in general, but to a certain extent
Short exposure = familiarity
Long exposure = novelty
Familiarization (preferred) is very brief compared to habituation (bored)
Visual acuity
Assess sharpness of visual discrimination
- Use preferential looking paradigm with boards of different stripes width against plains grey board.
Poor visual acuity at birth (very blurry). Start to have acuity 8-10cm away from the face (mom’s face when breastfeeding).
This is due to the immaturity of cone cells
Becomes normal at 8months old.
Colour perception
Black and white at birth
Colour vision appears at 2 months old
Adult vision at 5 months old (can differentiate diff shades of same colour during habituation phase)
Visual scanning
At birth, trouble tracking moving stimuli because eye movements are jerky
4 months old, can track slowly moving objects
8 months old, adult like visual scanning
Face perception
Infants have preference for face-like stimuli
Preference for top-heavy stimuli versus bottom heavy
ie. Preferred top heavy scrambled over bottom heavy, and over regular face. Means that they just prefer top-heavy, not just face-like
Children prefer their mom’s face to others just a few days after birth
Face specialist
6 months old can distinguish both human and monkey faces better than adults (generalists)
9months old start being better at human faces only (specialist)
This is caused by synaptic pruning (perceptual narrowing). Synaptogenesis = too many. Synaptic pruning = reduces.
Other-race effect (ORE)
Easier to distinguish faces from our own race.
Tested with habituation test in infants:
- 3 months old: distinguish equally between all of them
- 9 months old: only for own race
This is an exposure effect (not innate). Means that infant will not show ORE if equally presented with all races
Face perception in children with ASD
People with ASD often have difficulty with face perception
Toddlers prefer looking at geometric shapes than faces (opposite to normal kids)
Perceptual constancy
Perception of objects as being constant in size and shape in spite physical differences in retinal image
ie. Show infants cube repeatedly at diff distances. They looked longer at the larger and further away cubes meaning that they noticed the difference in size with original small cube.
Perceptual constancy is present at birth.
Object segregation
Identify that objects are separate from each other
ie. Used habituation of rod and block. 4mo preferred looking broken rod (means it’s novel, meaning they got it). Newborns looked for same amount of time (meaning they did not understand it)
Object segregation is not innate
Depth perception
Binocular disparity: difference between the retinal image of an object in each eye that results in two slightly different signals being sent to the brain
Perceived at 4 months old
The sensitive period is between birth and 3yo
It is a natural result of brain maturation, but they still need to receive normal input
Monocular depth cues: depth cues perceived with one eye. Perceived at 6-7 months old (using visual cliff). It needs to be developed through exercise.
Visual development timeline
- Birth: poor visual scanning / poor acuity / pref high contrast / B&W / pref faces / perceptual constancy
- 2 months: colour vision appears
- 4 months: object segregation / depth perception
- 5 months: adult like colour perception
- 6 months: face generalists / monocular depth perception appears
- 8 months: adult like visual scanning / adult like visual acuity
- 9 months: face specialists (perceptual narrowing)
Intermodal perception
Coordinated perception of a singular object or event through 2+ sensory systems. This is present very early on
Newborns can combine vision and touch (looked longer at pacifier they sucked on)
Newborns can combine vision and audition (looked more at the person playing the sound they heard)
Reflexes
Innate, adaptive, most of them disappear by 2 months
Crawling
Begin crawling at 7-8 months
This is not considered a milestone (some babies just skip to walking. Could be because of core weakness, hypersensitivity to floor, tonic neck reflex still present, insufficient opportunity)
Cultural differences motor development
Huge cross-cultural difference in how long children can sit at 5 months old.
Earlier sitting when baby spent little time in postural support
Later sitting when baby spent a lot of time with postural support
(Postural support is being held, or child adapted things, vs ground)
Babies spend a lot more time on the ground in countries like Cameroun vs Italy ie.
Some countries discourage children from exploring motor skills (ie China for hygiene reasons), vs North Africa country where they are highly encouraged.
ie. Infants show more mature walking when naked vs wearing diaper.
The role of weight changes
Stepping reflex disappears at 2 months, and then starts again at 7-12 months.
It disappears because infant gains weight faster than leg muscle.
Evidence because still show reflex in water
Importance of motivation
Individual differences in motivation predict when motor milestones are achieved.
Low motivation: movements occur infrequently, prefer activities that require low energy, require lots of stimulation to change position
High motivation: move often, prefer high energy activities, change position often, do not need stimulation to move
Highly motivated achieve ALL the milestones earlier than low motivations
Motor development and vision
Reaching enables object exploration which has consequences on visual development
Kids are able to sit and reach at 7 months old
ie. Infants that were more advanced in sitting and reaching were more likely to look at the incomplete display. Suggests that motor skills development in sitting and reaching influence development of 3D perception
ie. Beginner crawler confidently went down shallow AND steep slopes. Experienced crawlers avoided the steeps ones (same for walking). Suggests that infants have to learn from experience how to integrate perceptual information with each new motor skill developed
Scale errors
Attempt to perform an action on miniature object that is impossible due to the huge difference in size between child and object
Present until 2yo
Due to failure to integrate visual information with action planning
Motor development and Intentions
ie. Adults and 1yo showed same proactive gaze towards bucket
6 months old did not, they haven’t developed the ability to pick-up, carry and drop objects.
Means that infants ability to predict other’s actions rely on whether they could do it themselves or not
Music Cognition
The study of the abilities and processes required to engage with musical stimuli.
Reasons to study music for auditory development:
- similarity to language
- convenience
- evolution (music is innate, universal, adaptive)
Basics of hearing
- Wave is created, it travels in outer ear and causes eardrum to vibrate, triggering vibration in 3 small bones
- Sound-waves travel in cochlea where they are TRANSDUCED into electric signals
- Electrical signals travel along auditory nerve through brainstem and into primary auditory cortex
Building blocks of sound
Pitch: perception of the frequency of a wave (how many waves will fit in a place?). The more waves, the higher the frequency - The higher the frequency the higher the pitch. Measure in Hertz
Melody: sequence of pitches with logical sense. Made up on 2+ intervals. Has a contour ( pattern of intervals going up and down)
Prosody: using melody to convey meaning and emotion
Beat: evenly spaced points, felt as a pulse. Measure in bpm
Rythm: full pattern of temporal intervals in sequence
Timbre: tonal quality of a sound (flavour or colour). Allows to distinguish between types of sounds.
What a fetus hears
Low frequency sounds (high frequency are attenuated by fluid and tissue)
- Bowel sounds (irregular)
- Maternal heartbeat (slow)
- Fetal heartbeat (fast)
The cells to hear higher frequencies develop in a tonotopic fashion (grouped together by frequencies they hear). Earliest cells to develop are for low frequency. Transition happens gradually through infancy
Development of auditory system
Unresponsive to sound in first 20 weeks (cochlea not developed)
Auditory cortex becomes functional at 20 weeks and continues to develop up to 2 years old
Between 20-25 weeks, first responses to sound appear
35 weeks, cochlea is mature
40 weeks (term), basic auditory abilities are functional
Basic auditory abilities
Abilities present at birth:
- Localization (perceive spatial location of sound source)
- Identification ( perceive discrete speech sound (phonemes))
- Discrimination (hear differences between sounds)
Newborns can hear very wide of pitches, reduces over time (perceptual narrowing). Reasons:
- Attachment (bond with caregiver to ensure survival)
- Language (adopt native language)
NICU case
Pre-borns are overly exposed to high frequency sounds in hospital and underexposed to low frequencies.
They do not experience the gradual transition that normal infants do.
-> expose them to more low frequencies
ie. showed faster development in auditory cortex. Means that auditory plasticity can be evoked in pre-terms through exposure
Melody abilities: Discrimination and Singing
Discrimination: tasks measure the ability to detect differences. Reaches adult levels by age 10-11
Singing: measure the ability to math or repeat pitches and sequences (peaks at 12yo). In adolescence, influenced by musical training / puberty / shyness / music listening).
Absolute pitch
Ability to sing, name, identify a pitch without reference to another pitch
1 in 10,000 people born with it
Requires training from very early on
Needs to be acquired by 11
Rhythm abilities: Beat Perception and Synchronization
Beat perception: measure ability to find the beat. Learned by age 5
Synchronization: measure ability to move in time. Multimodal (some regions don’t develop until later). Can do steady beat by age 4 (not well to rhythmic sequences).
Perceiving vs Feeling musical emotion
Perceived emotion is inferred (linked to musical stimulus)
Felt emotion is evoked (linked to nervous system)
These can be different.
Children can perceive AND feel musical emotion.
By age 5 they can recognize happy and sad music (better for happy). Adult level by age 11.
By age 1 90% of children will dance and move to music (feel). More with familiar songs. Urge to move (groove)
Groove
Urge to move to music.
Syncopation: pattern of emphasis off the main beat, constantly associated with groove.
Groove is most strongly felt at a medium level of syncopation (inverted U).
ie. High groove is associate with more movement
High groove is associate with better timing accuracy
High groove is associated with higher pleasure and reward (75% expressed joy)
