Developmental Stages from Zygote to Infancy

Zygote

Travels fallopian tubes and implants in uterus

Three germ layers

Ectoderm: develops into nerve tissue and skin; Mesoderm: develops into muscle and bone; Endoderm: source of soft tissue such as organs

Embryo

Embryotic period is the foundation of the rest of development; Most vulnerability to threats

CNS differentiation

Week 4: Differentiates forebrain, midbrain, hindbrain, and spinal cord

Sexual differentiation

Week 6: Gonads turn into testes or ovaries; White matter grows (myelin, neural connections); Week 7: Cells forming cerebral cortex move to final destination

Fetus

Lasts 40 weeks, 37 to 42 is typical; Premature babies put in incubator; Age of viability: 24 weeks, 50/50 chance of survival

Down syndrome

Faulty cell division: full or partial third copy of 21st chromosome; Increased risk with increased maternal age; Risk increases with age

Teratogen

Factors that can harm the zygote, embryo, or fetus; Linked to ADHD, Autism, etc; Most common and preventable source: recreational drugs like tobacco, alcohol, opioids, etc

Thalidomide

Caused birth with partial body parts, hands with no arms, feet with no legs, etc

Weed

Linked to Autism, learning disabilities, etc

German measles contraction

Highly dependent on timing; 5th week: devastating, blindness and even death; 37th week: Nothing

Nicotine

Can increase the chance of SIDS; Increases the chance of low birth weight, premature births, etc

Fetal Alcohol Syndrome

Several physical abnormalities including growth delays, cognitive and behavioral problems, reduced IQ, attention problems, poor impulse control

Reflexes at birth

Turn heads toward touch, Open mouths, Search for the mother's nipple (rooting reflex), Sucking reflex, Grasp objects placed in hand, Stepping reflex

Newborn activity

Sleep 16 to 18 hours a day, Alert looking, Physical movement of arms and legs

Newborn Sex and Gender Development

Sex: based on XX/XY genotype; Gender: maleness/femaleness continuum based off personal feeling of maleness/femaleness

Variation in sex chromosomes

Turner syndrome: X0 chromosome, phenotypically female; Klinefelter syndrome: XY, phenotypically male; Jacob syndrome: XYY, phenotypically male

Newborn Senses

Measured using habituation; High sensitivity to smells; Fetus can hear very well (7 months); Young infants don't see detail at a distance

Physical Changes: Infancy and Childhood

Rapid growth in gray matter, 64% brain growth between birth and end of 3rd month; Cephalocadual and Proximodistal development

Gender development

Preferences for sex-typed toys at 12-18 months; Consistent use of gender labels at 3 years old; Interaction between bio and experience

Piaget's Theory

Thought of kids as 'little scientists'; Kids and adults may not always get to the same conclusion

Assimilation

Incorporating new experiences into existing schemas

Accommodation

Adjusting existing schemas to incorporate new information

Schema

Mental categories used to organize information

Object Permanence

Understanding objects exist even when out of sight

Egocentrism

Inability to see others' perspectives

Concrete Operational Stage

6-12 years; improved logic and conservation skills

Conservation

Understanding quantity remains the same despite changes in appearance

Theory of Mind

Understanding beliefs and intentions of others differ from one's own

Attachment

Infant's bond with primary caregiver, impacting social development

Secure Attachment

Infant uses caregiver as a secure base for exploration

Parenting Styles

Varied approaches based on support and behavioral regulation

Puberty

Start of adolescence with physical and brain changes

Observational Learning

Learning by observing others' behaviors

Reflex

Innate, automatic response to a stimulus

Instinct

Inborn, complex behavior patterns independent of experience

Learning

Permanent behavior change resulting in new abilities

Associative Learning

Forming connections between stimuli or behaviors

Classical Conditioning

Association between two stimuli occurring sequentially

Operant Conditioning

Linking behaviors with consequences

Habituation

Decreasing response to repeated, harmless stimuli

Sensitization

Increased reaction to stimuli after exposure to a strong stimulus

Unconditioned Stimulus

Stimulus that naturally triggers a response

Conditioned Response

Learned response to a previously neutral stimulus

Extinction

Reduction in learned response when conditioned stimulus is no longer paired with unconditioned stimulus

Generalization

Tendency to respond to stimuli like the original CS

Discrimination

Learned ability to distinguish between conditioned stimuli that are similar

Higher order conditioning

Stimuli associated with CS also elicit CRs

Latent inhibition

Slower learning that occurs when a CS is familiar compared to an unfamiliar CS

Counterconditioning

When a stimulus that one doesn't like happens at the same time as a liked stimulus

Systematic desensitization

A type of counterconditioning where one relaxes while exposed to fear-provoking stimuli

Flooding therapy

Intentionally overwhelming someone with fear to reduce that fear

Addiction

Friends who use the addictive item become stimuli to continue using the item

Attitudes and prejudice

The idea that your body learns less when a stimulus is familiar applies to prejudice and attitude as well

Creativity

People who are creative can form new connections quickly, even with familiar things

Schizophrenia

Correlates with high intelligence and a lack of latent inhibition

Positive reinforcement

Increases positive outcomes by adding something favorable

Conditioned reinforcer

Gains value because it is associated with other things of value

Negative reinforcement

Increases behaviors linked to escape/avoidance of unpleasant consequences

Punishment

Eliminates or reduces the frequency of a behavior

Partial schedules of reinforcement

Desired behavior is reinforced only on some occasions

Fixed Ratio schedule (FR)

Reinforced after a specific interval/number of behaviors

Variable ratio schedule (VR)

Reinforcement occurs after some variable numbers of behaviors

Fixed interval schedule (FI)

Reinforce first response after a specific interval

Variable interval schedule (VI)

Reinforce first response after varying amount of time

Method of successive approximations (shaping)

Method for increasing the frequency of behaviors that rarely/never occur

Latent learning

Learning that occurs in the absence of reinforcement

Token economy

Uses tokens that can be exchanged for reinforcers to increase the frequency of behavior

Imitation

Copying behavior unlikely to just occur

Bobo dolls

Used in experiments on aggression and modeling behavior