Introduction to Psychology 1XX3
Each of these levels of analysis frames different questions which lead to different answers to
give you a richer understanding of complex problems.
Development: gene-environment interactions across an individual’s 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 between
conception and death.
o Maturation: the biologically-timed unfolding of 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 to
a 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. Relatively
permanent changes in our thoughts, behaviours, and feelings as a result of our
Interactionist Perspective: the view that holds that maturation and learning interact during
Maturation and Learning
Some essential systems must be in place before learning proceeds. You won’t learn to walk until
you’ve developed muscles in your torso and limbs and the ability to balance: you won’t 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 to
play 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
Studying Development Development
Many researchers who study human development focus much more on changes that occur in
infancy and childhood compared to any other time in the lifespan.
Although there are subtle developmental changes through adulthood, changes that occur earlier
in 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 John’s life. The
changes 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 early
years play an especially important role in shaping who you become.
One way to study an infant’s basic sensory capabilities is to use the habituation procedure to
determine if an infant can detect the difference between two stimuli.
Infants normally tend to show interest in novel objects in the environment. That habituation
process 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 same
stimulus is repeatedly presented, the infant’s responses will 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 of
Dishabituation: an increase in the responsiveness to a stimulus that is somehow different from
the habituated stimulus.
To measure event related potentials, a special cap with an array of electrodes is carefully placed
on the scalp.
These sensitive electrodes can detect changes in electric activity across a population of neurons
in 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 to
understand an infant’s sensory interactions with the environment.
One clever met