Upload
michelle-rivera
View
217
Download
0
Embed Size (px)
Citation preview
7/28/2019 Psych 1XX3 Development
1/4
Development
Introduction to Psychology 1XX3
Introduction
Each of these levels of analysis frames different questions which lead to different answers togive you a richer understanding of complex problems.
Overview
Development: gene-environment interactions across an individuals lifespan. Evolution: gene-environment interactions across the evolutionary history of a species. Neuroscience: the study of the nervous system, and the neural basis of thought and behaviour.
Introduction to Development
Introduction to Development
Development: refers to the changes and continuities that occur within the individual betweenconception and death.
o Maturation:the biologically-timed unfoldingof changes within the individual. How that plan unfolds is influenced by specific environmental conditions that
shape the genetically-determined processes.
In the right environment, a particular genetic plan might lead Harlan toa maturation timeline in which he will grow his first baby tooth at 5
months, start walking at 12 months, enter puberty at 12 years, and
finally die at 80 years.
o Learning: the acquisition of neuronal representations of new information. Relativelypermanent changes in our thoughts, behaviours, and feelings as a result of our
experience.
Interactionist Perspective
Interactionist Perspective: the view that holds that maturationand learning interact duringdevelopment.
Maturation and Learning
Some essential systems must be in place before learning proceeds. You wont learn to walk untilyouve developed muscles in your torso and limbs and the ability to balance: you wont talk until
your mouth and tongue have reached a certain level of dexterity.
o If a child was given proper nutrition but isolated in a dark room, never being allowed toplay or interact with anyone. You would expect problems in developing normal vision,
speech, and motor and social skills compared to any other child exposed to normal
environmental stimulation.
Studying Development
7/28/2019 Psych 1XX3 Development
2/4
Development
Many researchers who study human development focus much more on changes that occur ininfancy and childhood compared to any other time in the lifespan.
Although there are subtle developmental changes through adulthood, changes that occur earlierin life are much more dramatic than those occurring later in life.
Dramatic Changes Early in Life
Imagine tracking the developmental changes that occur in a five-year span of Johns life. Thechanges that take place in his life between ages 40-45 are much more subtle than the dramatic
changes that take place in his life between ages 1-5.
Many researchers believe that the developmental changes that take place during these earlyyears play an especially important role in shaping who you become.
Habituation Procedure
One way to study an infants basic sensory capabilities is to use the habituation procedure todetermine if an infant can detect the difference between two stimuli.
Infants normally tend to show interest in novel objects in the environment. That habituationprocess begins by repeatedly presenting the infant with the same stimulus, such as tone or a
picture, while measuring changes in physiological responses, like head or eye movements.
When a novel stimulus is presented, an infant will initially show a burst of activity. As the samestimulus is repeatedly presented, the infants responses wi ll return to baseline levels. At this
point, the infant has demonstrated habituation to the stimulus.
Habituation: a decrease in the responsiveness to a stimulus following repeated presentation ofthe stimulus.
Dishabituation: an increase in the responsiveness to a stimulus that is somehow different fromthe habituated stimulus.
Event-related Potentials
To measure event related potentials, a special cap with an array of electrodes is carefully placedon the scalp.
These sensitive electrodes can detect changes in electric activity across a population of neuronsin the brain. The particular behaviour being measured will evoke changes in various brain
regions of interest.
High-Amplitude Sucking Method
Together, habituation and ERP provided complementary behavioural and neural measures tounderstand an infants sensory interactions with the environment.
One clever method takes advantage of the fact that infants can control their sucking behavioursto some extent, which can be accurately measured by a special pacifier in the high-amplitude
sucking method.
In this procedure, you first measure the baseline sucking ate for the infant in the absence ofrelevant stimuli. During the shaping procedure, the infant is given control over the presentation
of a stimulus to be tested such as a series of musical notes.
o If the infant sucks on the pacifier at a faster rate than baseline, a switch is activated inthe pacifier that causes the stimulus to be presented. If the infant can detect themusical notes and likes what she hears, she can keep the musical notes playing for
longer by increasing her sucking rate.
o But if the infant doesnt like the sounds, she can stop sucking sooner to end thepresentation.
Preference Method
In the preference method the infant is put in a looking chamber to simultaneously look at twodifferent stimuli.
7/28/2019 Psych 1XX3 Development
3/4
Development
The researcher can accurately measure the direction that the infant is looking to tell if moreattention is being directed to one stimulus over the other.
Using this procedure, researchers have found that infants tend to prefer looking at big patternswith lots of black and white contrasts and prefer looking at faces.
Competence-Performance Distinction
An individual may fail a task not because they lack those cognitive abilities. But because they areunable to demonstrate those abilities.
o A child who is preverbal will be unable to respond to your question on her preferencesbetween two different toys. If you were unaware that the child was preverbal, you may
wrongly assume that failure to respond to your questions indicates that she is unable to
discriminate between the two toys. However, given a better test, the child may be able
to demonstrate her preference to you.
Introduction to Developmental Research Methods
Look At How Anilities Change Over Time
While many experiments in psychology are typically concerned with single time points,developmental studies are often concerned with repeated measures over time.
o For example, a typical study on memory might look specifically at the performance forremembering a list of numbers in an undergraduate population at a single test point.
The Longitudinal Design
Longitudinal Design: a developmental research design in which the same individuals re studiedrepeatedly over some subset of their lifespan.
Advantages of Longitudinal Design
You track each person over time as they develop, and you could uncover any links between howthey did early in life with hoe they did later in life. You could find patterns that are common to
all people.
Disadvantages of Longitudinal Design
It is very expensive and time consuming. Selective Attrition: loss of participants in a study such that the sample ends up being non-
responsive of the population as a whole.o Some participants may quit, become unfit to continue, or even die, leaving a
fundamentally different sample at different time points.
Practise Effects: changes in participants response due to repeated testing.Cross-Sectional Design
Cross-Sectional Design: a developmental research design in which individuals from differentage groups are studied at the same point in time.
Advantages of Cross-Sectional Design
Allows researchers to assess developmental change. Relatively less time consuming and expensive; can uncover age differences.
Disadvantages of Cross-Sectional Design
Cannot distinguish age effects from generational effects. Cannot assess developmental change.
Introductory to Hereditary Transmission
Chromosomes and Genes
The zygote doesnt remain a single cell for long; it quickly divides at an exponential rate, growingfrom two cells to four cells, to 16 cells and so on, until at birth, you end up with billions of
different ells, each with the same 46 chromosomes inherited at conception
Cell Division
7/28/2019 Psych 1XX3 Development
4/4
Development
Monozygotic twins: are genetically identical because they come from the same sperm andovum, which formed one zygote, and then split into separate zygotes.
Dizygotic twins: are no more genetically similar than any two siblings, because they come fromtwo different sperm and ova, and start off as two different zygotes from the moment of
conception.