ch4: development Flashcards
development
growth and change over time, including changes that are progressive (learning to walk or talk) and regressive (declines in cognitive functioning with age)
teratogens
environmental substances or agents that negatively impact the developing organism during gestation, particularly during the period of the pregnancy (impacts physical development and cognitive functioning)
what are some commonly known teratogens
alcohol, smoking, drugs, and certain medications
period of the zygote
during prenatal development, the time from conception until about two weeks later. ends when the blastocyst implants into the uterine lining (driven by genetic factors)
what is the primary characteristic of the period of the zygote
rapid cell division, the cells divide exponentially, from 2 to 4 to 16 to 256, and as cells divide, the centre of the cell becomes hollow
blastocyst
the hollowed-out ball of cells that implants into the uterine wall, to become the developing organism and its support system
ectopic pregnancy
a pregnancy that results from the implantation of the blastocyst into one of the fallopian tubes instead of uterine wall (mother and the zygote are at risk)
what is the difference between uterus and fallopian tubes that makes ectopic pregnancy risky
unlike the uterus that can expand and contract to accommodate and expel the fetus, the fallopian tubes do not have this ability. if the pregnancy is not terminated, there is a risk of rupturing fallopian tube, leading to death
monozygotic twins
“identical twins”, they have 100% shared genetics. it occurs when one egg was fertilized by one sperm and splits into two separate cells with identical DNA (almost identical genetic information, and always the same sex)
dizygotic twins
“fraternal twins / non-identical twins”, occurs when in the rare case of woman’s ovaries releasing more than one egg at a time, two eggs are each fertilized by separate sperm cells. approx sharing 50% of their genetic information (may be of diff sexes, similar to other siblings born years apart)
the period of the embryo
during prenatal development, from when blastocysts implants into the uterine lining to about eight weeks after conception, during which teratogens are most impactful
what is the primary characteristic of the period of the embryo
major developmental advances, all of the major organs and systems of the body undergo significant development during this stage
cephalocaudal principle of development
the principle indicating that development occurs from the head to the tail during prenatal development (changes occur in the brain and the head before changes in the extremities)
proximodistal principles of development
during gestation, development proceeds from the internal organs outward towards the extremities (first centrally located features, like heart or lungs, then more peripheral features, like hands or fingers)
what is the difference between cephalocaudal and proximodistal principles of development
the cephalocaudal principle emphasizes development from head to tail, while the proximodistal principle emphasizes development from the centre of the body outward
what is accomplished by the end of the period of the embryo
all major bodily structures are formed, but the embryo cannot survive outside of the uterine environment
period of the fetus
from nine weeks after conception to birth, classified as a period of growth and minor refinements (final period of prenatal development)
what are the characteristics of the period of the fetus
- refinements and finishing touches
- gains weight and moves into the head-down position preferred for childbirth
- fetal brains develop the sulci and gyri
- fetus learn from the world outside the uterine environment
- they can discriminate between the voice of their mother and unfamiliar woman
- pregnant ppl can recognize how their fetuses behave, which may be indicators as to how infants would behave after birth
what are the three factors associated with teratogens that adds to the complexity of effects of teratogens on prenatal development
- dose: how much exposure a pregnant person had to a teratogen
- timing: when in gestation the teratogen was experienced
- cumulative effects: the possibility that the pregnant person may have been exposed to more than one teratogen and the effects combined may be difficult to disentangle
which method is most commonly used to determine teratogens on pregnant people
correlational research and some focuses on non-human animal models
we know that only thru experiments can we determine causation, but why is it unethical to conduct experiment on pregnant people to determine possible teratogens
It is unethical to randomly assign pregnant women to an experimental condition (e.g., exposure to teratogens) that might negatively impact their developing infant.
teratogens have the most negative effect during which prenatal stage
the period of the embryo because during this stage, the most major bodily structures are being formed, and exposure to harmful environmental agents can cause significant negative effects
how do teratogens affect the other two stages
exerts less influence during the period of the zygote (cellular division is largely constrained by biology) and the period of fetus (less impact on formation of major bodily structures during this stage but have impacts on brain development and cognitive functioning)
fetal alcohol spectrum disorder (FASD)
occurs to infants who have been exposed to alcohol during pregnancy, represents a range of conditions associated with being exposed to alcohol prenatally, most significant of which is fetal alcohol syndrome (FAS)
how does alcohol effect the developing infant
damage to internal organs, altered physical characteristics, and cognitive impairments
what is thalidomide
prescription medication used during the 1960s to alleviate the symptoms of morning sickness experienced by pregnant people, it reduces sensations of nausea but at the cost of the health of the developing infant
what is the effect of thalidomide on developing infant
infants were born with shortened or malformed limbs as thalidomide is commonly prescribed during the period of the embryo, during which major structures are formed
zika virus
- transmitted by mosquitoes or sexual contact with the infected, associated with microcephaly (smaller infant head sizes)
- pregnant individual experience rash, itchy skin, and joint pain
- significant abnormalities for infants, including stillbirth, microcephaly is not the outcome but part of the series of abnormalities (restricted growth in utero and alterations in the developing brain)
long term effects of Zika virus on children
motor impairments, epilepsy, microcephaly was maintained in the majority of the older children as well
how does microcephaly affect everyday behaviour
associated with poorer scores on a standardized developmental assessment of cognitive, language, and motor functioning, it is also indicated that severity of microcephaly is related to greater seizure severity
what are some significant gains experienced by infants over the first three years of life
- motor development (control over both large muscle groups for walking and small muscle groups for grasping)
- language development (producing their first word around 12 months of age)
- cognitive development (long term memory for past events by 20 months of age)
- social development (forming significant personal connections or attachments to caregivers over the first two years)
cognitive development
refers to how the brain develops and how we gain cognitive skills such as information processing, problem solving, language learning, etc
Jean Piaget’s theory on cognitive development
- focus on addressing the manner in which infants and children construct their knowledge
- children are active contributors to their own learning, they construct their own knowledge (constructivist theoretical perspective)
- also stated that growth of cognitive structures occurs when encountering conflicting information in the world
through which processes does modification of cognitive structures occur
assimilation and accommodation (are fluid and changes over time to account for newly learned information)
assimilation
the incorporation of new information into existing cognitive structures, encountering new information that is similar to what is stored in the existing cognitive structures, which is then added to the existing cognitive structures
accommodation
the creation of new cognitive structures to house new information that does not fit elsewhere
equilibration
states in which cognitive structures agree with external realities (agreement between what children see in the world and the reality that exists in their minds)
disequilibration
cognitive structures do not agree with external realities (what exists in the outside world is not represented in the created cognitive structures)
what happens when disequilibration occurs
cognitive structures must be modified thru assimilation and accommodation to allow greater agreements and maintain equilibration
what are the four major stages of cognitive development children progress through
the sensorimotor period, the preoperational period, and the concrete operational period occur during infancy and childhood. the formal operational period occurs in adolescence (no skipping stages, must progress through each stage in order) (children in diff stages think very differently, and some may never achieve the formal operational stage)
sensorimotor period
first stage of cognitive development, lasting from birth to age 2. characterized by learning that occurs through a child’s sensory and motor interactions with the physical environment (have six substages)
first substage of sensorimotor period
birth to 1 month, infants learn from the world using reflexes
second substage of sensorimotor period
1 to 4 months, infants engage in primary circular reactions, or repeated actions on their own bodies
third substage of sensorimotor period
4 to 8 months, infants engage in secondary circular reactions on objects outside of their bodies
fourth substage of sensorimotor period
8 to 12 months, object permanence is achieved, infants combine secondary circular reactions so they can make a sequence of events come to pass (ex. finding toys hidden under a cloth)
fifth substage of sensorimotor period
12 to 18 months, children engage in tertiary circular reactions as they experiment with different items in various contexts, “little scientists”
sixth substage of sensorimotor period
18 to 24 months, children engage in mental representation, they can remember and act on past experiences
primary circular reactions
infants learn about the world by repeatedly engaging in actions on their own bodies (occurs in second substage) (they’re primary because they are focused on the infant’s own body and circular because behaviours are repeated)
secondary circular reactions
infants learn about the world by repeatedly engaging in actions outside their own bodies (occurs in third substage) (ex. dropping toys off the side of their chairs
object permanence
an understanding that objects and individuals continue to exist even if they cannot be seen, a development that occurs around 9 months of age
the A-not-B task
indicates that although infants show some rudimentary memory abilities, they must make significant strides to reach the level of cognitive competency experienced by older children and adults (infants experience difficulty shifting their attention when objects are first hidden at one location then moved to another)
tertiary circular reactions
“little scientists”, infants actively explore the world using different combinations of items to see how these changes affect their observed outcomes (occurs in the fifth substage)
mental representation
infants remember and re-enact situations and events that happened previously without any ongoing perceptual supports (occurs in the sixth substage)
preoperational period
second stage of cognitive development, occurs from ages 2 to 7. marked by a child’s increasing ability to use symbols and engage in logical thinking
preoperational period is further divided into which two substages
- preconceptual thinking: from ages 2 to 4
- intuitive thinking: from ages 4 to 7
symbolic thinking
significant growth during the preoperational period, children become more adept at using language to convey their thoughts and feelings, and readily engage in pretend play
what are some difficulties children experience during the preoperational period
animism, egocentrism, and conservation tasks
animism
preschooler beliefs that stuffed toys and other inanimate objects have feelings
egocentrism
difficulty of children in adopting the perspective of another individual, as seen in children aged two to seven in Piaget’s model (studied egocentrism using the three mountains problem)