Infancy: Sensation, perception and learning
• Nonate: A newborn baby.
A new baby’s reflex
• They have well-developed reflexes and sensory responses.
• Reflex: A human’s involuntary response to external stimulation. First behaviors.
• Some are permanent (Eye blinking, withdrawal reflex, biceps reflex patellar
tendon aka knee jerk) some are temporary (palmar reflex, sucking response) that
disappear after year of life.
• Abnormalities in babies reflex indicator for problems with hearing, vision
• See table 4-1 (pg 119), know meaning of each reflexes.
• Infant state: a recurring pattern of arousal in the newborn ranging from alert,
vigorous, wakeful activity to quite, regular sleep. It tells us form beginning
behavior is organized and predictable. Human are not passive, we react to
• Two basic states, sleeping (70% of time) and waking.
• First few weeks few but longer sleep period,
• 8 weekssleeping more during night, less during day
• 1 yearsleep through the night
• Less fussy as she gains more control over her state of arousal
• Sleeping style differ in different cultures. Co-sleeping has been linked to SIDS
• Sudden infant death syndrome (SIDS): SIDS refers to the sudden and
unexpected death of a healthy infant under 1. The death remains unexplained
after all possible causes of death have been ruled out.
1 • REM and non-REM sleep: rapid eye movement is characterized by rapid, jerky
movements of the eyes and in adults, is often associated with dreaming.
Fluctuation in heart rate and blood pressure. When awaken repeatedly as people
begin their REM cycle, they tend to be irritable. Infant spend 50% of their sleep in
REM activity, where’s adult append only 20%. This activity is absent in the
remaining non-REM sleep.
• Autostimulation theory: Theory that during REM sleep infant’s brain stimulates
itself and that in return stimulates early development of the central nervous
Basic (hunger related, lowloud gradually, rhythmic, cry-rest-inhale-rest)
Angry: (removal of toy, cry-rest-inhale-rest but each stage may vary in length)
Pain: (discomfort, sudden onset, long crysilence due to holding breathshort
• Mother>Father>non parent able to distinguish their own baby’s cry.
• Colic: A prolonged period of unexplained crying in an infant.Lasts several hours
at a time and “piercing”. Occurs in 20% of infants
How to soothe an infant
• Infants can sooth themselves- by sucking on finger or hand. Sucking on sweet
substances sooths better than something plain tasting.
• Parents can sooth their babies using pacifiers, rocking, massaging or swaddling.
Swaddling is when a baby is wrapped tightly in a blanket or cloth thus keeping
her limbs immobile.
Evaluating the Newborn’s Health and capabilities
Other than testing baby’s reflexes, there are other tests –
• Brazelton Neonatal Assessment Scale: A scale used to measure an infant’s
sensory and perceptual capacities (orientation to sight, sound); early learning
capabilities (familiarity or habituation to sensory stimuli); motor development
(muscle tone); infant state and their ability ot regulate them (like soothability).
The scale also indicates whether the brain and the central nervous system are
2 properly regulating autonomic responsivity. Used to identify infants at risk of
developmental problems and intervention techniques (teaching parent’s about
their infant’s capacities).
• Using this scale found Gussi (West Africa)community’s infants have better motor
skills than US+Canada because of their vigorous caring (caring them in a loose
sling, making them hang on tight)by caregiver.
The infant’s Sensory and Perceptual Capacities
• Sensation: The detection of stimuli by the sensory receptors. Biologically
prepared to respond to social stimuli.
• Perception: The interpretation os sensations in order to make them
meaningful. Biologically prepared to respond to social stimuli.
Unlocking the Secret’s of babies’ Sensory Capabilities
• Violation-of-expectation method: Introduces an unusual or impossible side
(a cube rolling or floating on the ground) and baby alters her behaviour
showing discrimination proving babies knows something about how the object
• Visual preference method: A method of studying infant’s abilities to
distinguish one stimulus from another by measuring in length of time they
spend attending to different stimuli. Longer stare=preference.
• Habituate: The process by which an individual reacts with less and less
intensity to a repeatedly presented stimuli, eventually responding faintly or not
at all. (eg: startled by a dog’s bark at first but eventually getting used to it so,
then no reaction).
Hearing: Babies are good listeners
• Fetus may hear complex sound outside mom’s body.
• For a newborn sound must be louder and high pitch (babies are less sensitive ot
• Motherese: Adults knowing instinctively to talk to babies’ in high pitched voice.
• Infants know where sounds are coming from and at what speed (eg: backing
away from an approaching sound source at a certain pace)
3 • Auditory Localization: The ability to determine from where in space a sound is
• Babies’ are sensitive to rise and fall of pitch (some say that’s why you should
make fetus or babies listen to Mozart, to increase their brain activity. So they get
smarter. That is not true).
• Babies like human voice over anything and are able to discriminate voice soon
(mom vs. other woman).
Vision: How babies see their world
• Vision of infants under 1month range from 20/200 to 20/800 but by 6 moth
reaches adult range.
• 1 week old can distinguish and prefer black stripes over solid color.
• Visual acuity: Sharpness of vision; the clarity with which fine detail