Ch 11 Flashcards
Development
The growth and change in an organism over time
→ progressive: growth (learning how to walk or talk)
→ regressive: decline (decline in cognitive functioning over time)
Cross-sectional research design
Comparing individuals of different ages at the same point in time (e.g. 2020: survey 10/20/30 year olds) that can be tested all at once
Issues:
→ different cohorts grew up in different time periods
→ different experiences, cultural changes, environmental changes
Longitudinal research design
Repeatedly test the same individuals as they grow older
-cohort: group of individuals who share some trait
Issues:
→ time-consuming
→ people drop out
→ uncertain if the changes are generalizable to all people or just the group (eg. people born in that year)
Sequential research design
Repeatedly test multiple age cohorts as they grow older (combination of cross-sectional and longitudinal)
→ most comprehensive but also the most time-consuming
→ helps avoid the issues of both cross-sectional and longitudinal research designs
Common developmental paradigms
- Investigating abstract concepts
- working with individuals who may not be able to verbalize their experience
Studying infant reflexive behaviour
High amplitude sucking paradigm
→ uses sucking frequency to measure preference/interests
Habituation paradigm
→ novelty vs familiarity preferences
→ through trials, habituation occurred more slowly in complex stimuli than it did with simple stimuli
Violation of expectation paradigm
Studying voluntary behaviours
False belief paradigm
→ used to asses/measure theory of mind (the idea that you are aware of your own internal processes and understand that other people have internal processes that are separate from yours)
Elicited imitation paradigm
→ behavioural test of recall memory
Questionnaire data
- can be used alone or in conjunction with behavioural measures
- useful tools because parents usually know infants best
- subject to bias or fallible memories
Ethical considerations
- must work with institutional review boards for study approval
- consent from parents and assent from children
- some studies require debriefing
Practical considerations
- Difficulties with finding or recruiting participants
- homogenous samples (not very many people of different demographics; limitations can lead to bias)
- non-representative or bias samples may affect generalizability of research findings
Prenatal development
Fertilization:
-Sprerm and ovum (egg cell) → zygote (fertilized egg)
- zygote attaches to uterine wall 10-14 days after conception
- Germinal stage— the zygote
- begins once fertilization occurs
- characterized by rapid cell division
- blastocyst: hollow ball of cells (implants in uterine wall)
- twinning:
→ dizygotic (fraternal): two eggs released during ovulation, two different sperm, can be different sexes
→ monozygotic (identical): one egg released during ovulation, one sperm, same sex - Embryonic stage— the embryo
- begins once implantation occurs (2 -8 weeks after conception)
- life-support structures: placenta and umbilical cord (allows embryo to take resources from the mother’s bloodstream)
- organs and systems form
- cephalocaudal principle of development: development occurs from head to toe (top to bottom) during prenatal development
- proximodistal principle of development: development proceeds from the internal organs outward towards the extremities - The fetal stage— the fetus
- occurs 9 weeks after conception
- muscles strengthen and systems develop
- eyes open by 24 weeks
- viable by 28 weeks
- refinement
Genetics and sex determination
-Humans have 46 chromosomes (23 pairs from each parent; the 23rd pair is either X or Y)
- females: XX males: XY
- Y chromosomes:
→ contain testosterone determining factor (tdf) which initiate the development of testes (secrete androgens)
→ tdf must be present within the critical period (6-8 weeks) in order to develop male physiology
→ if tdf is not present within critical period then there will be insufficient androgen activity which leads to the default female physiology
Sex chromosome anomalies
Missing or damaged chromosomes:
→ Turner syndrome (X0)
Extra chromosomes:
→ Triple X syndrome or trisomy (XXX)
→ Klinefelter syndrome (XXY)
→ Jacobs syndrome (XYY)
Teratogens
Environmental agents or substances that can negatively impact prenatal development
→ important factors: dose, timing, cumulative effects
Examples:
- maternal drug use
- maternal illness and exposure to toxins
- maternal nutrition and emotions
Cognitive development
How the brain develops and how we gain cognitive abilities like information processing, problem solving, language learning etc.
William James
Suggested that a newborn’s world is “buzzing, blooming confusion”
→ in other words, they are passive, disorganized, have an empty mind
→ they are surrounded by stimuli that they don’t know what to do with
→ starting with a blank slate
Not the case because:
- tactile, auditory, and chemical perceptual systems are stimulated in the womb and operational at birth
Visual system at birth
- The visual system is not stimulated until birth
- develops in a continuous fashion (gradual incease); as infants are exposed to more things their perception gets better
- at 3-4 months they begin to interpret visual stimuli (organized according to Gestalt principles: subjective contours, closure etc.)
- discriminate internal features of face (prefer looking at faces over other stimuli)
Preferential looking procedure
Measures how long infants look at a stimulus; newborns look longer at stimuli they find interesting, complex, or familiar
Newborn learning
- Habituation: repeated stimuli causes familiarity and causes infants to stop attending to the stimuli
→ Discriminate different speech sounds: playing the same auditory sounds over and over will cause the infant to stop reacting to it - Aquire classically conditioned responses
- Simple observational learning (ex. Imitating adult facial expressions)
Audition
Sound localization:
- infants will react to sounds by turning towards the direction of the sound
- U- shaped function (acquired at birth, disappears at 4 months, reappears at 6 months)
Phoneme discrimination:
- exceeds that of an adult
- disappears at the age of 1
Music perception:
- shows similar responses of consonant (happy) and dissonant (uncomfortable) patterns as adults
Jean Piaget
- The father of cognitive development
- his theory is constructivist and dialectical
→ constructivist: building up the understanding of the world (constructing knowledge; active process) through experience
→ growth occurs when children encounter conflicting information that changes their perspective - assimilation: add new information encountered to similar existing cognitive structures
- accommodation: create new cognitive structure to account for information that does not fit in existing cognitive structures
- equilibrium: when there is agreement between what children see in the world and the reality that exists in their minds
- disequilibrium: when what exists in the outside world is not represented in the created cognitive structures (leads to assimilation or acomodation)
Preoperational stage
- ages 2-7
- world represented symbolically through words and mental images (enables pretend play)
- child does not understand conservation (mass, volume etc.)
- thinking displays irrevisibility, centration, animism (inanimate objects have feelings), and egocentrism (focus on self)
Sensorimotor stage
- occurs from birth to 2 years
- understand world through sensory experiences and physical interactions with objects
- begin to acquire language
- object permanence: understanding that objects continue to exist even when they can no longer be seen (occurs at about 8 months)
Concrete operational stage
- Ages 7-12
- easily perform basic mental operations involving tangible problems and situations (things that they can imagine occurring or have encountered before)
- Have difficulty with problems that require abstract reasoning (things that cannot occur or haven’t occured)
