Psych 125
Human Development
Christopher Gade
Office: 1031-G
Office hours: Tu 12-1:30 and by apt.
Email: gadecj@gmail.com
Class: T 1:30-4:20 Room 2210
Starting Off…
• Let’s turn in those first assignments!
Looking at Motor, Sensory, and
Perceptual Development
• So far we’ve examined how our bodies change
and grow, how our environment and body
throughout development relate to health
changes, and how our nervous system grows and
then declines with age.
• In today’s class, we’ll focus on the last physical
related topic of development
– Motor development
– Sensory/perceptual development
Movement/Touch and the Nervous System
• The value of Movement
and Touch
– Interact with the
environment
– Detect danger/injuries
– Derive pleasure from the
environment
• Our Basic Systems
– Nervous system
– Motor and sensory systems
Our
Sensory
and Motor
System
More on Nerves
• Action/Sensory Nerve
– Cranial
– Spinal
• Sensory (afferent) root
• Motor (efferent) root
Examining Motor Development:
How Do We Get There?
• Maturation – Motor development that results
from an unfolding of growth through experience
and genetics in a predictable pattern
• Dynamic systems theory – a theory that
attempts to explain maturation by examining
the combination of perception and action
– Perception – identification and recognition of a
desirable stimulus in the environment
– Action – attempts to coordinate movement in order to
obtain that desirable stimulus
An Early Bag of Tricks: Reflexes
• Despite being very vulnerable at birth, newborns
do have a few motor skills that can help increase
their chances of survival.
– Reflexes – built-in physical reactions to stimuli
• What are the reflexes that we’ve identified
– Rooting reflex – a stroke of the cheek causes the
infant’s head to turn toward the contact
– Sucking reflex – any object placed in the mouth causes
an instant sucking motion
– Moro reflex – when startled, infants arch their back,
throw back their heads, & fling out their arms and legs
More on Reflexes
• Other reflexes that we’ve identified
– Palmar grasp – touching the palm of the hand with an
object causes the infant to grasp around that object
– Plantar grasp – touching the sole of the foot causes
the toes to spread open and foot
to curve inward
– Stepping reflex – feet on a flat
surface will cause infant to
“walk”
– Swimming – infants placed in
water will stroke with legs and
arms while holding their breath
Any others?
• A lot of our reflexes at birth persist throughout life
– Coughing
– Sneezing
– Blinking
– Shivering
– Yawning
• The ones listed previously usually disappear at
about 3-4 months of age
– Sucking exception
– Development issues and the continuation of reflexes
What About What We’re Not Born With?
• Gross motor skills – skills that involve large-muscle
activities
• Posture
–
–
–
–
–
2 weeks – hold our heads
2 months – able to sit while supported
6 months – able to sit on own
8-9 moths – able to pull ourselves up to a stand
10-12 months – able to stand
• Walking
– At about 1 year, infants begin to attempt to walk, the big
challenge is learning how to shift their weight between
feet when they are moving them
– This is a continual learning process, with terrain and angles
all needing to be learned
Later Gross Motor Development
• 1-2
–
–
–
–
Standing along easily
Coordinating movement
Climbing steps
Walking quicker
–
–
–
–
Squat without falling
Walk backward
Kick and throw a ball
Jump
Later Gross Motor Development
• 3-4
– Hopping
– Running
– Run to jump
• 4-5
– walk down stairs
– Coordinate movements
• 5-adolescence
– Development centers around experience
– Smoother behaviors and coordination are a result of
repeated actions
Adolescence to Adulthood and Beyond
• Our motor system continues to be capable of
getting better and better as we age into early
adulthood
• At about 30, our motor systems start
to decline
• Note: As mentioned earlier, this decline can be
very rapid, or very slow, depending upon our
levels of activity and health as we age
Development of Fine Motor Skills
• The ascent
– Our fine motor skills greatly increase into adulthood
due to new connections and myelination
– Experience helps in fine motor skill growth
• The descent
– Once we reach adulthood, our fine motor skills often
decline just like our gross motor skills
– Neural noise – irregularities in neural activity in the
central nervous system
– More use of fine motor skills greatly slow the decline
– Oftentimes, fine motor skills are close to those of
younger adults, but require more time
Moving On…
• Now onto the second part of today’s class,
Sensory and perceptual development
Sensation and Perception
• Sensation: the conversion of energy from the
environment into a pattern of responses by the
sensory receptors
• Perception: the interpretation of that information.
• In order to understand how we interact with the
environment, we need to understand both parts.
Let’s See How Good We Are At This
• Tasks to show how
this works
– Pick up an object
• Eyes closed
• Eyes open
– Catch an object
– Clap in unison
Specific Types of Sensory Development
• In this section, we’re going to focus our discussion
of sensation and perceptual growth on two
categories
– Vision
– Hearing
– Touch
– Taste/
Olfaction
Visual Development: Looking at the Eye
• The eye has a number of parts that are critical to
our ability to sense the visual stimuli in our
environment
– The lens
– The fovea
(rods and
cones)
Vision at Birth
• Because most of our eye’s structures aren’t fully
formed, newborns have extremely limited vision
– Visual acuity – ability to see things at a distance
• 20/240 at birth
• 20/40 by 6 months
• Close to normal by about
1 year
– Color vision – ability to
detect colors
• 4-8 weeks can detect color
• 3-4 months can show
color preferences
Visual Development: Looking at the Mind
• The brain also plays a
critical role in our
interpretation of stimuli
– Perceptual constancy –
ability to perceive objects
as the same across
different shades, shapes,
and sizes
• Starts to form at 3 months
• Develops until early
adolescence
• Depth perception – a
Another
combination of the
Development of the
ability to pick up on
information presented
Mind in Vision
by the lens, our ability
to interpret colors, and
understand binocular
cues (information about
depth that we gain
through the use of both
eyes)
– 2-4 months of age
display a basic
understanding of depth
Later Vision Development
• Childhood
– By 3 to 4 we begin to detect color boundaries much better
– By 4 to 5 our eye muscles become flexible enough to focus
on information up close
• Adolescence to adulthood
– Unlike most other types of development, very few physical
changes take place in vision during this stage
• Adulthood on
– As we age, we begin to lose a lot of visual functions
•
•
•
•
•
Visual acuity
Response to glare
Dark adaptation
Color vision
Depth perception
Hearing Development
• Unlike vision, our hearing is fairly in tact not only
at birth, but even up to two months before birth
– Sound/voice identification
– Locating ability
– Range of frequency
– Range of volume
• As we age, our ability to hear declines first at the
higher and lower end of the frequency spectrum,
then as we get into our late 70’s early 80’s, all
frequencies decline
The Frequency Range of Hearing
Looking Back at Today…
• Up to today, we had examined how our bodies
change and grow, how our environment and body
throughout development relate to health
changes, and how our nervous system grows and
then declines with age.
• In today’s class, we focused on the last physical
related topic of development
– Motor development
– Sensory/perceptual development
In Our Next Class
• We’ll be having our first exam…
• Details
– 40-60 multiple choice questions
– Questions based on the lectures, but information
covered in the text AND in lecture will have a very
good chance of being in the exam
– Class is over after the exam
– No phones or bags open during the exam