Developmental Psychology Study Notes

Developmental Psychology Notes

Overview

  • Course taught by Nancy L. Segal, Ph.D.

  • Focuses on the various stages and aspects of developmental psychology, from infancy to adolescence.

Infancy (Birth - 2 years)

  • Language Explosion: Rapid increase in the complexity and use of language.

Reflexes

  • Definition: General involuntary responses to stimulation.

  • Examples:

    • Optical Blink: Eyes shut in response to bright light.

    • Rooting Reflex: Tickle the corner of mouth; the head turns to the source of stimulation.

    • Sucking Reflex: Involuntary sucking when the mouth is stimulated.

    • Grasping Reflex: Fingers close around an object placed in the palm.

    • Automatic Walking: Reflexive walking motion when feet touch a surface.

Newborn Sleep States (Wolff's 7 States)

  • Regular Sleep: Full rest with little motor activity.

  • Periodic Sleep: Transitional state between regular and irregular sleep.

  • Irregular Sleep: Characterized by limb motion, facial expressions, irregular breathing.

  • Drowsiness: Eyes alternately open and close between sleep and wakefulness.

  • Alert Inactivity: Eyes open, attentive with even breathing.

  • Waking Activity: Uneven breathing, motor activity, and presence of crying.

  • Crying: Vigorous motor activities associated with distress.

Types of Sleep

  • REM (Rapid Eye Movement): More prevalent in babies than adults.

  • nREM (Non-Rapid Eye Movement): Babies spend less time in this state.

  • Notably, premature infants spend more time in REM sleep than non-premature infants.

  • By 4 months, infants usually exhibit around 8 hours of regular sleep daily.

APGAR Scores

  • Developed by Virginia Apgar (1953): Scoring system to assess newborns' health.

  • Measured at 1 and 5 minutes after birth (and optionally at 10 and 20 minutes):

    Sign

    0

    1

    2


    Heart rate

    None

    < 100/min

    100-140/min


    Respiratory effort

    None

    Weak gasps

    Good crying


    Reflex irritability

    None

    Weak

    Strong


    Muscle tone

    None

    Some flex

    Active movement


    Color

    Blue

    Body pink

    Completely pink

    • Interpretation:

    • 7+ = Good health

    • 4-6 = Help needed

    • 3- = Danger

Sudden Infant Death Syndrome (SIDS)

  • Definition: Sudden Infant Death Syndrome occurs under the age of one but peaks between 2-4 months.

  • Risk factors: Includes prematurity and low APGAR scores, along with low birth weights.

  • Impact: Leading cause of infant mortality, accounting for approximately 20% of infant deaths in the U.S.

Other Neonatal Scales

  • Examples: Brazelton, Bayley scales that assess various aspects of neonatal development.

  • Cultural Differences: Varies widely in irritability responses, as seen in responses to loud noises, exhibited in films by Daniel Freedman.

Crying and Responses

  • Types of Cry:

    • Basic Cry: Usually associated with hunger.

    • Anger Cry: Distinct from other cries; expressed more vigorously.

    • Pain Cry: Sharply high-pitched and indicates distress.

  • Developmental change: Note that between 2-3 weeks, infants start showing basic feelings toward their caregivers.

Infant Learning

  • Definition: Learning is described as behavioral change over time due to experiences.

  • Classical Conditioning:

    • Terms:

    • UCS (Unconditional Stimulus): Natural stimulus (ex: sugar).

    • UCR (Unconditional Response): Natural response (ex: sucking).

    • CS (Conditioned Stimulus): Neutral stimulus (ex: touch).

    • CR (Conditioned Response): Response to the CS (ex: sucking).

    • Process:

    • UCS (sugar) + CS (touch) → UCR (sucking),

    • After repeated pairings, CS alone will elicit CR.

  • Extinction: Decline of the CR when presenting the CS alone without UCS.

  • Habituation: Decline in response strength with repeated stimulation; contrasted with recovery when a new stimulus is introduced.

Operant Conditioning

  • Definition: Infants act on their environments; consequences affect the probability of behavior repetition.

  • Research by Dr. Carolyn Rovee-Collier:

    • Studied 2-3 month old infants and noted novelty responsiveness in infants interacting with their environment.

Memory

  • Infantile Amnesia: Inability to recall specific events during the first few years of life (typically ages 1 to 3).

  • Imitation: Infants can copy behaviors as early as 12-21 days old.

  • Types of Memory:

    • Recognition Memory: Typically evident in 2-4 months as the ability to recognize previously displayed objects.

    • Production Memory: Recall of absent stimuli, usually at ages 8-12 months.

Motor Development

  • Benefits:

    • Better control of environment.

    • Enhanced understanding of the world.

    • Improved social relationships.

  • Cephalocaudal trend: Development progresses from head to feet.

  • Proximo-distal trend: Development progresses from center outward.

Motor Milestones

  • Pre-reach: Until 2 months, evidence of pre-reaching behavior.

  • Ulnar Grasp: 3-4 months, fingers grasping towards the palm (clumsily).

  • Pincer Grasp: Develops by the end of the first year, typically around 9 months.

Depth Perception

  • Definition: Ability to judge distances from oneself and between objects.

  • Kinetic Depth Cues: Develop as early as 3 weeks through movement.

  • Binocular Depth Cues: Apparent by 2-3 months through differing visual input from each eye, with 3D perception emerging.

  • Pictorial Depth Cues: Develop around 7 months and include cues like shading used by artists.

Visual Cliff Experiment (1961) - Eleanor Gibson

  • Investigated depth perception in infants.

Sensitivity to Movement

  • Vestibular Sensitivity: Awareness of body orientation and motion, developed at a young age.

  • Stereotypical Behavior: Defined as rhythmic and repetitive behaviors seen in infants, such as kicking and rocking.

Touch and Pain Sensitivity

  • Well-developed at birth, including sensitivity to pain (observed with heel prick and circumcision tests).

  • Research by Dr. Tiffany Field: Demonstrated that premature babies massaged three times daily gained weight significantly faster and showed much faster nervous system maturation.

Smell (Olfaction)

  • Olfactory Cues Impact: Studies showed that infants can recognize their mothers based on smell.

Significance of Research in Development

  • Highlights the critical impact of both biological and environmental factors during development stages.

  • Ethical, philosophical, and practical implications shed light on parenting techniques, educational policies, and healthcare practices in neonatal care.

Historical Context and Anecdotes

  • Twins Cases: Discussed which involve legal considerations and emotional responses to unexpected family dynamics from baby switches at birth (as seen in “Someone Else's Twin” by Nancy L. Segal).

  • Parental emotional response upon discovering a baby switch can lead to issues of identity and self-concept changes.

  • Legal considerations discuss how courts handle compensation for lives that have been affected by mistakes in medical care.

  • Nature vs. nurture debates arise from cases of twin separations.

Maternity Certainty/Uncertainty

  • Research into how mothers utilize olfactory, auditory, and tactile cues to identify their infants, addressing concerns regarding paternity and maternity uncertainty.

Statistical Data in Delivery Systems

  • Incidents Recorded: An estimated 20,000-23,000 incorrect transfers of babies reported annually in the United States.

  • Emphasis on improving methods for tagging babies at birth, use of electronic wristbands, and legislative changes to enhance safety protocols in hospitals.

Conclusion

  • Continuous development and changes in healthcare practices reflect the need for ongoing research in developmental psychology and the implications such research holds for understanding human behavior and development across the lifespan, with a particular emphasis on infancy through adolescence.