FSHD 3239/24-9/26Physical DevelopmentPart I: Infants & Toddlers I. Reflexes – inborn, automatic response to a particular form of stimulationA. Controlled by the lower brain centers that control other involuntary processes like breathingB. Infants have approximately 27 different reflexes1. Some reflexes are permanent 2. Other reflexes disappear during infancy as other areas of the brain become more developed and infants have increasing control over their bodies (primitive)Rooting for a nipple (sucking reflex), induce swallowing reflex, stepping reflex, Babinski reflex (bottom of baby’s foot is straight), grasping reflex, flailing arms when feel dropping sensationC. Why reflexes1. Survival (ex: rooting for feeding)2. Evolutionary adaptive function (ex: cling to mothers)3. Practice for later motor development (ex: palmar grasp)4. Parent-Child bonda. Encourage responsivenessb. Signal need, sootheD. Why are we interested in reflexes?1. Indicators of neurological development Ex: no Babinski reflex means that there is a lower spine defect2. Normative developmental progression a. Individual differencesII. Infant States – recurring patterns of arousal ranging from waking to sleepingA. As with adults, infant states are organized, predictable and regulated by internal forces. 1. Become more adult-like by end of 2 years – total sleep declines,longer periods of wakefulness- Sleep patterns become more controlled by light-dark (naturalcircadian) than by fullness-hungerB. Newborn States (table 4.2, p. 130)1. regular sleep – 8-9 hours2. irregular sleep – 8-9 hours3. drowsiness - 0.5-3 hours4. quiet alertness - 2-3 hours5. waking activity and crying– 1-4 hoursFSHD 3239/24-9/26III. SleepA. Newborn spends 70% of time sleeping, and there are gradual shifts in circadian timing 1. by 4 weeks periods of sleep are longer and fewer2. 6 months – melatonin (drowsy when dark) – prior to that fullness and hunger control sleep states 3. by 1 year most infants can sleep through the night 4. cultural differences in patternsB. REM (rapid-eye-movement) sleep – characterized by rapid jerky eye movements, fluctuating heart rates and blood pressure; brain-wave activity similar to awake1. associated with dreaming in adults2. Infants (starting in-utero) spend about 50% of sleeping time in REMsleep - By 3-5 years and into adulthood: about 20%3. Auto stimulation Theory – During REM sleep the infant’s brain stimulates itself, in turn stimulating development of the central nervous systema. As people can perceive and process more of their environment, they require less auto stimulation, so time in REM decrease(1) Pre-term infants spend more time in REM(2) Infants with more physical and social stimulation spend less time in REM sleep(3) Disturbed REM patterns linked to development of later motor, cognitive and language difficultiesIV. CryingA. Developmental pattern: across cultures1. peaks at 6 weeks, then declines sharply by 3 monthsa. may become more related to psychological than physical needs 2. more crying at night 3. individual patterns B. 3 patterns – cross-cultural although adult response patterns may vary1. Basic – linked to hunger; starts low and gets louder and more rhythmicFSHD 3239/24-9/262. Angry – similar to basic pattern but less organized with longer periods of crying and shorter periods of inhaling 3. Pain – sudden, loud, long cry followed by holding breath and short gaspsC. Adult Responsiveness – human response1. diversity in response patterns within and across cultures- Beliefs about child development- Own feelings of perceptions2. differential skill in interpreting infant cries, in general:- Mothers better than fathers- Women better than men- Parents better than non-parents 3. Soothing an Infanta. Individual differences in soothability – can be tied to neurological damage or temperament b. Self-soothing – a goal of infants (and certainly of parents!) is to develop strategies to self-regulate emotions- sucking is a common response that is even seen in uteroo effectiveness decreases unless accompanied by contact with a caregiver- Turning headc. parental soothingi. the great debate – go to the baby or let him/her “cry it out”ii. sleep training (controlled comforting, camping out) studies done with 7 month oldsiii. American research: holding baby on shoulder is most effective way to sootheiv. Other cultures – swaddlingV. Sensory DevelopmentFSHD 3239/24-9/26A. Development of the senses and perception is a continuous process that begins in utero and continues to improve throughout infancy and in some cases throughout childhood.B. Development of the senses and perceptual capabilities should be seen as integrated and dynamic processes.C. Infants seem to be “hardwired” from birth for human interaction that in turnpromotes further development.VI. Smell, Taste and Touch – see textbookVII. HearingA. Develops in uteroB. Neonates (newborns):1. require louder volume (10-17 decibels)2. hear high pitch sounds better (by 2 years no pitch differences)C. Preference for human speech1. Neonates show preferences for their mothers’ voices.2. Attend more to human speech 3. Infants can hear all possible language sounds.a) 6-8 months - distinguish and prefer own language sounds4. Statistical learning capacity – analyze speech stream for regularsound sequences D. Musical preference1. Show preference for music versus noise and for certain kinds ofmusic, including major chords and melodiesVIII. Vision – least developed at birth (brain and eye structures undeveloped)A. Acuity – sharpness of vision, including fineness of discrimination1. Newborns can only see objects clearly that are close to the face2. Visual acuity develops rapidly in infants so that by 6-8 months,infants’ vision is comparable to adults’.3. Infants have poor contrast sensitivity; they can see patterns only when composed of highly contrasting elements.a) Size, shape, and arrangement of the cones (neural cells that aid in color and detail perception) are still developingB. Color – Infants can distinguish colors by at least 3 months of age.C. Face Preference – Predictable developmental patterns1. Scanning PatternsFSHD 3239/24-9/26a) Neonates: small sections of the outer parts of the faceb) 2 months: focus more on interior features of the facec) 3 months: perceive the whole face2. Infants prefer attractive (symmetrical) faces3. Female bias