Week 4 Flashcards
Sensation
external stimuli activate sensory receptors
Perception
interpretation of sensory stimulation by the brain
What are the 4 techniques for testing infants
- Preference paradigm
- Habituation/Dishabituation
- Operant Conditioning
- Violation-or-expectation paradigm
Preference Paradigm
-Assesses how much time infant is looking at one stimuli over another
Testing Visual Acuity
Use Teller acuity cards to determine if lined pattern is visible based on a consistent increased looking time toward the patterned side
Visual Acuity at birth
30x worse than that of an adult
Contrast sensitivity at birth
20 to 25 times worse than adults
Do newborns prefer to look at fine lines or more contrasting photos
more contrasting photos because fine lines are make it hard to see contrast
What aspects of vision do newborns show deficits in
-visual acuity
-contrast sensitivity
-convergence
-coordination
-color perception
Do infants prefer face-like stimulus or other stimulus? and what is the functional significance
Bias for top heavy patterns
-babies attend to faces, which improves face perception
At what age to babies begin to look longer at average or attractive faces
5-months old
What biases are infants born with
-listen preferentially to mom’s voice and familiar story
-look preferentially at face-like stimuli
-turn their head to smell mom’s breast pad over a stranger’s breast pad
-eat foods experienced prenatally
Habituation/Dishabituation
-responses decrease to repeated stimuli
-when the stimulus changes, our response changes accordingly
-looking time increases only if infants perceive the difference between stimuli
What is the purpose of habituation/dishabituation?
Allows us to test for discrimination
-not a preference
Can newborns discriminate shapes
Yes, unless in contour
Preference-looking paradigm
Measure infants looking or head turning toward visual or auditory stimuli
Preference-looking Paradigm race preference
By 3 months, babies have a preference for faces of their own race
-no preference at younger ages
-perception becomes fine-tuned with experience to match environment
Role in experience in discrimination of monkey faces
at 6 months you, 9 months no
Purpose of Operant conditioning
shows an overt preference
Operant conditioning
-teach infants to do behavior 1 to receive stimulus A, and behavior 2 to receive stimulus B
-compare amount of behavior 1 vs 2
Auditory development in infants for language
-preference for mid-frequency tones (Human speech)
-preference for high-pitch speech
-speech over backwards speech
-categorical perception of phonemes
Auditory development in infants for music
EARLY PERCEPTURAL BIASES
-natural pauses in music (4 to 6 months)
-consonant over dissonant tones
PERCEPTUAL TUNING (9-12 months)
-musical scales
-musical rhythms
Controlled Sucking Behaviour
-Teach infants to suck faster to hear A and suck slower to hear B
-compare how much time infants ended up listening to A or B
-type of operant conditioning
Intersensory Redundancy
Infant’s perceptual system is particularly attuned to amodal information presented to multiple sensory modes
-in a young brain signals are redundant allowing for better understanding of the world
-with age/experience, neurons become specialized and babies can interpret the world with single-modality inputs
Amodal
not belonging to a single sensory mode
Synesthesia
Experience one sense through another
Intersensory Redundancy: sight and touch of pacifiers
Infants look longer at pacifiers that match the tactile sensation of what they are sucking on
Intersensory Redundany: Emotional expression
-infants watch video of female actress portraying an emotion expressions
-present a difference emotion: 1. audio and visual, 2. video only, audio only
-4 moths could discriminate with both
-5 month could discriminate with just auditory
-7 months could discriminate with just visual
Attention
Processes that allow people to control input from the environment and regulate behaviour
Types of Attentional Networks
ALERTING NETWORK
Keeps attentional processes prepared, ready to detect and respond to stimuli
ORIENTING NETWORK
Selects which stimuli will be processed further
EXECUTIVE NETWORK
Monitoring thoughts, feelings, behavior
ADHD
-3-7% of school aged children
-4:1 boys to girls
-hyperactivity and impulsivity vary in degree
-inattention
Inattention
Unable to stay on task, difficulty maintaining prolonged attention
Experience-Expectant Processes
brain was waiting for visual input to set up neural architecture for visual preception
Experience-Dependent Processes
Brain Specializes in processing information that is in the environment
Face perception in monkeys reared with no exposure to faces
-infant monkeys raised in visually rich environments, yet with in exposure to faces
-following deprivation, monkeys selectively exposed to human or monkey faces for 1 month
-during deprivation preference preferred faces over objects
-After month of exposure preferred type of face exposed to
Violation-of expectation paradigm
infants will show surprise when witnessing unexpected events
