Physical Development in Infancy: Cephalocaudal and Proximodistal Patterns

Cognitive Development in Infancy

• Piaget's (1954) Theory of Infant Development:
  • Schemes: mental representations
  • Assimilation: using existing schemes to deal with new information
  • Accommodation: adjusting schemes to fit new information
  • Organization: grouping of isolated behaviors and thoughts into a higher-order system
  • Equilibration: mechanism by which children shift from one stage of thought to the next

Sensorimotor Stage in Infancy

• Simple reflexes: sensation and action are coordinated through reflexive behaviors (e.g., rooting and sucking)
• First habits and primary circular reactions: coordination of sensation with a focus on the infant's body
  • Habits (reflex) → From voluntary → e.g., grasp things, suck their mouth
  • Primary circular reactions: schemes based on reproducing events that initially occurred by chance
• Secondary circular reactions: infants become more object-oriented, moving beyond preoccupation with the self
  • Actions are repeated because of their consequences
  • Imitates simple actions and physical gestures
• Coordination of secondary circular reactions: combines vision and touch, hand and eye
  • Actions become more outwardly directed → point something
  • Readily combines and recombines previously learned schemes
  • Presence of intentionality (e.g., knocking over one block to reach and play with another)
• Tertiary circular reactions: schemes in which an infant purposely explores new possibilities with objects
  • Continually doing new things to them and exploring the results
  • Internalization of schemes: developing the ability to use primitive symbols
  • Object permanence: understanding that objects and events continue to exist even when they cannot be seen, heard, or touched

Learning and Memory

• Joint attention: two or more individuals focus on the same object or event
• Memory:
  • Implicit memory: memory without conscious recollection
  • Explicit memory: conscious remembering of facts and experiences
• Maturation of the hippocampus and cerebral cortex (especially important for physical development in infancy)

Physical Development in Infancy

• Cephalocaudal pattern: head-to-tail development
• Proximodistal pattern: center-to-extremities development
• Brain development in infancy:
  • Shaken baby syndrome: serious brain injury resulting from forcefully shaking an infant
  • Early deprived environment associated with impairment in brain development (but reversible in some individuals)

Motor Development

• Body reflexes in infancy:
  • Rooting reflex: when the infant's cheek or the side of the mouth is touched, they turn their head to find something to suck
  • Sucking reflex: when an object is placed in the infant's mouth, they automatically suck
  • Moro reflex: when there is a sudden, intense noise or movement, the infant throws their head back, flings out arms and legs, and arches their back
  • Grasping reflex: when something touches the infant's palms, they react by grasping tightly
• Gross motor skills: large-muscle activities (e.g., rolling, sitting, crawling, standing, and walking)
• Fine motor skills:
  • Palmar grasp: grasping with the whole hand
  • Pincer grip: grasping small objects with thumb and forefinger

Sensation and Perception

• Sensation: the product of the interaction between information and sensory receptors (e.g., eyes, ears, tongue, nostrils, and skin)
• Perception: the interpretation of what is sensed
• Visual preference method: measures the length of time infants attend to different stimuli to determine whether they can distinguish between stimuli
• Habituation: decreased responsiveness to a stimulus after repeated presentations
• Dishabituation: recovery of a habituated response after a change in stimulation
• Color vision: infants can discriminate between some colors by 8 weeks
• Perceptual constancy: allows infants to perceive the world as stable
  • Size constancy: recognition that an object remains the same even though the retinal image of the object changes as you move toward or away from the object
  • Shape constancy: recognition that an object's shape remains the same even though its orientation changes
• Perception of occluded objects: infants don't perceive objects that are occluded by other objects as complete in their first month
• Depth perception: "Visual cliff" experiments by Eleanor Gibson and Richard Walk
• Hearing: fetus can hear sounds in the mother's womb during the last two months of pregnancy
• Touch, smell, and taste: newborns can respond to touch and feel pain, differentiate odors, and prefer salty tastes at 4 months of age

Intermodal Perception and Individual Differences

• Intermodal perception: ability to relate and integrate information from two or more sensory modalities (e.g., vision and hearing)
• Individual differences in attachment:
  • Chess and Thomas' (1977) classification: easy, difficult, and slow-to-warm-up children
  • Kagan's (2002) behavioral inhibition: inhibited and sociable children
  • Rothbart and Bates' (2006) classification: extraversion/surgency, negative affectivity, and effortful control

Contextual Influence and Socialization

• Reciprocal socialization: bidirectional influence between children and parents
• Caregiving style and attachment: caregivers' behavior influences attachment style
• Social orientation: face-to-face play starts at 2 to 3 months of age
• Joint attention and gaze-following: help infants understand that others have intentions
• Social referencing: "reading" emotional cues in others to help determine how to act in a particular situation

Attachment and its Development

• Attachment: a close emotional bond between two people
• John Bowlby's (1969, 1989) four phases of attachment:
  1. From birth to 2 months: infants direct their attachment to human figures
  2. From 2 to 7 months: attachment becomes focused on one figure (primary caregiver)
  3. From 7 to 27 months: specific attachments develop
  4. From 24 months on: children become aware of others' feelings and goals and account for them in their own actions