Brain, Perception, and Motor Development - Infancy

Brain, Perception, & Motor Development: Infancy

The Organized Newborn

  • Reflex: Involuntary and automatic responses to stimuli.
Types of Reflexes
Name of ReflexResponseDevelopmental Course
Palmar graspCurling fingers around objects that touch the palmBirth to about 4 months
RootingTurning head and tongue toward stimulus when cheek is touchedDisappears over first few weeks of life
SuckingSucking on objects placed into the mouthBirth to about 6 months
MoroStartle response to loud noise or sudden change in position; arms thrown out, back archesBirth to about 5-7 months
BabinskiFanning and curling the toes when stroking the bottom of the footBirth to about 8-12 months
SteppingMaking stepping movements when held uprightBirth to about 2-3 months
SwimmingHolding breath and moving in waterBirth to about 4-6 months
Neonatal Behavioral Assessment Scale (NBAS)
  • Evaluates baby’s reflexes, muscle tone, state changes, responsiveness to physical and social stimuli, and other reactions (Berk, 2013, p. 138).

Learning Capacities

Classical Conditioning
  • Steps of Classical Conditioning.
    • Unconditioned Stimulus (UCS): Breast milk
    • Unconditioned Response (UCR): Sucking
    • Neutral Stimulus: Forehead stroking
    • Conditioned Stimulus (CS): Forehead stroking
    • Conditioned Response (CR): Sucking
Additional Learning Capacities
  • Habituation: Gradual decline in response intensity, frequency, or duration to a repetitive stimulus (p. 142).
  • Recovery: Increased responsiveness following habituation due to a new stimulus (p. 142).
  • Imitation: Learning by copying others' behavior (p. 145).
Habituation Procedure (Flom & Bahrick, 2007)
  • Time/Trials Looking (sec) and visual recovery outcomes for habituation trials.

Infant States

Table of Infant States of Arousal
StateDescriptionDaily Duration in Newborn (hours)
Regular sleepBaby still, eyes closed, breathing slow and regular.8-9
Irregular sleepEyes closed, move under eyelids (REM), breathing irregular.8-9
DrowsinessFalling asleep/waking up, eyes glazed, breathing regular but rapid.1/2-3
Alert inactivityEyes wide open, exploring environment, even breathing.2-3
Alert activityEyes open, irregular breathing, fussy, bursts of motor activity.1-3
CryingIntense, difficult to stop, high levels of motor activity.1-3
Sleep States
  • REM Sleep: Irregular brain activity resembling waking, uneven heart rate, slight movements.
  • NREM Sleep: Regular sleep state, slow breathing and heart rate.

Motor Development

Gross and Fine Motor Development
  • Gross Motor Development: Control of large body movements (p. 157).
  • Fine Motor Development: Control of small finger movements (p. 160).
Growth Trends in Infancy
  • Cephalocaudal: "Head to tail"; control of head before arms and trunk, legs last.
  • Proximodistal: From the center of the body outward; head and trunk control before limbs (Kuther, 2023, pp. 670, 678).
Dynamic Systems of Motor Development
  • Reflects interaction among developmental domains, maturation, and environment.
Biological and Contextual Determinants of Motor Development
  • Maturation of CNS, growth of muscles, practice opportunities, environmental support, child's goals.
Milestones in Motor Development
  1. Head Erect and Steady: 6 weeks
  2. Elevates Self by Arms: 3 weeks - 4 months
  3. Rolls from Side to Back: 2 months
  4. Grasps Cube: 2 months
  5. Sits Alone: 7 months
  6. Crawls: 7 months
  7. Pulls to Stand: 8 months
  8. Stands Alone: 11 months
  9. Walks Alone: 11 months 3 weeks
  10. Walks Up Stairs (with help): 14 months

Sensation and Perception

Vision
  • Least developed sense at birth; visual acuity reaches adult levels between 6 months and 1 year.
  • Preference for patterns and faces.
  • Color vision improves with age (Kuther, 2023, pp. 168-169).
Depth Perception
  • Ability to perceive distances and the visual cliff experiment shows the association of crawling experience with fear of heights (Kuther, 2023, pp. 170-171).
Hearing
  • Most developed sense at birth; newborns hear as well as adults and prefer speech sounds (Kuther, 2023, p. 171).
Touch
  • Critical for learning; skin-to-skin contact reduces stress responses and pain sensitivity develops before birth (Kuther, 2023, p. 172).
Smell and Taste
  • Well-developed at birth; infants discriminate between tastes and prefer sweetness (Kuther, 2023, p. 172).