Infant Vision Development Quiz

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Questions and Answers

At what age do infants typically achieve adult-like visual acuity?

12 months

2 months

5 months

8 months (correct)

Which color do infants usually perceive first as their color vision begins to develop?

Green

Blue

Red (correct)

Yellow

What change in visual tracking is observed in infants by 4 months of age?

They show no interest in moving stimuli.

They have jerky eye movements.

They can track only stationary objects.

They can track moving objects smoothly. (correct)

What is the primary reason for the improvement in visual scanning abilities in infants?

Maturation of the visual cortex and brain Signup and view all the answers

What hypothesis is suggested about infants' preference for faces or face-like stimuli?

It is due to an innate mechanism for face perception. Signup and view all the answers

What indicates that infants perceive a larger cube as a novel stimulus?

Infants looked longer at the larger but further away cube. Signup and view all the answers

Which cue plays a significant role in helping infants to segregate objects?

Movement of the objects Signup and view all the answers

In the habituation study with the rod, what was the primary question being investigated?

If infants perceive the rod as one single object or two separate objects. Signup and view all the answers

What does the result of infants looking longer at the larger cube imply about their perception?

Infants perceive the repeated presentations of the original cube as constant in size. Signup and view all the answers

What aspect of perceptual constancy is evidenced by the infants' reaction to the cubes?

Infants perceive objects as constant despite changes in their retinal images. Signup and view all the answers

What is the legal definition of childhood?

Human beings below the age of 18 Signup and view all the answers

What anatomical trade-off is associated with the evolution of childhood in humans?

Large brain and narrow hips Signup and view all the answers

Which of the following characteristics describes children in relation to learning?

Readily imitate others Signup and view all the answers

Why is a longer childhood considered essential for humans?

To maximize learning opportunities Signup and view all the answers

What is one of the reasons younger humans are vulnerable compared to other species?

They depend on adult caregivers for a longer period Signup and view all the answers

In the context of child development, what does the term 'malleable brains' imply?

Children's brains are adaptable and capable of learning Signup and view all the answers

Which aspect of child development focuses primarily on emotional and social skills?

Social development Signup and view all the answers

What is primarily involved in the process of learning to transition from dependence to independence in child development?

A range of perceptual, cognitive, emotional, and social capabilities Signup and view all the answers

At what age do babies typically begin crawling?

7-8 months old Signup and view all the answers

What likelihood is there that a healthy baby will skip crawling entirely?

It is common for most babies. Signup and view all the answers

What is a major reason why some infants may skip crawling?

Insufficient physical strength Signup and view all the answers

Which of the following statements best reflects cultural differences in motor milestones?

Milestones are influenced by how infants spend their time. Signup and view all the answers

Which factor is NOT a common reason for cultural differences in how infants develop motor skills?

Parental education level Signup and view all the answers

How does the presence of postural support affect infant motor skill development?

It delays their ability to sit or crawl. Signup and view all the answers

What is a consequence of wearing diapers for infants learning to walk?

They show less mature walking abilities. Signup and view all the answers

Which factor contributes to individual differences in motor development?

A combination of several factors Signup and view all the answers

What happens to the stepping reflex in infants?

It disappears at about 2 months then reappears. Signup and view all the answers

What is the average age for infants to start walking?

10-11 months Signup and view all the answers

What indicates that a 4-month-old understands that a rod behind a box is a single object?

They prefer to look at the broken rod. Signup and view all the answers

What is necessary for infants to develop normal binocular vision by age 3?

Normal visual input from both eyes. Signup and view all the answers

At what age do infants typically start to perceive monocular depth cues?

6 months Signup and view all the answers

What aspect of visual perception do infants demonstrate by looking longer at a non-mammal after being habituated to mammals?

Categorization skills Signup and view all the answers

What influences infants’ preference for stimuli in a laboratory setting?

Length of exposure to an initial stimulus. Signup and view all the answers

Which developmental aspect allows children to categorize objects based on shared function or behavior around 9 months old?

Conceptual categorization Signup and view all the answers

What major milestone comes after infants are able to sit without support?

Pull self to stand Signup and view all the answers

What is an example of an infant's innate reflex?

Grasping an object in their palm Signup and view all the answers

What key ability begins developing at birth and involves the coordinated perception of an object through multiple sensory systems?

Intermodal perception Signup and view all the answers

Which area of vision development is considered experience-dependent and requires learning?

Binocular depth perception Signup and view all the answers

What is a primary focus of infants in the first few months regarding visual interest?

High contrast, complex stimuli Signup and view all the answers

What categorization skill develops in children by 2-3 years old?

Forming category hierarchies Signup and view all the answers

What developmental timeline milestone occurs at 8 months?

Face specialization Signup and view all the answers

Study Notes

Course Overview

Mondays, 12-1 pm office hours or by appointment
Email for alternative time
Midterms and final exams are multiple choice, final exam is cumulative

What is Childhood

Legal: Under 18 years old
Biological: Physically immature human
Psychological: A distinct difference exists psychologically between children and adults

What it Means to be a Child

Dependent on Adult Caregivers
- Longer childhood compared to other species
- Makes children vulnerable and time consuming to care for
Long Childhood
- Primates have long childhoods
- Humans have the longest
- Due to a large brain and narrow hips trade-off
Large Brain, Narrow Hips Trade-Off
- Human brains are large and complex compared to other animals
- Larger brains mean larger heads
- Bipedalism favored narrow hips
- This creates a conflict between large heads and narrow hips
- To solve this conflict, babies are born underdeveloped and their brains continue to develop after birth

Fundamentally About Learning

Born partially undeveloped to maximize learning opportunities
Children are adapted to learn
- Highly curious
- Suggestible
- Readily imitate others
- Overestimate their own abilities
- Malleable brains
Learning is only possible with the support of adults

Child Development

The learning process of developing perceptual, cognitive, emotional, and social capabilities that allow humans to transition from dependence in infancy to independence in adulthood

Topics Covered In This Course

Early Development
- Visual and Motor Skills
Cognitive Development
- Learning about the world, social cognition, and language
Social Development
- Emotional development, attachment, family and peer relationships, and morality

Why Study Child Development

Lots of age memorization in this course

Visual Development - Visual Acuity

Infants have immature cone cells in their retinas
- Cone cells are light-sensitive neurons that help with seeing fine detail and color
By 8 months, infants have adult-like visual acuity
At birth, visual ability is the least developed sense

Visual Development - Color Perception

At birth: Infants only see in grayscale
2 months: Color vision develops (red usually first)
5 months: Adult-like color perception
- Cone cells and visual cortex are fully developed
- Can discriminate between color categories and hues within one category
Color Discrimination Studies
- Habituation paradigm
  - Habituate infant to a red color
  - Test phase presents green (different category) or a different hue of red

Visual Development - Visual Scanning

From birth: Infants scan their environment and pause to look at items (but have trouble tracking moving stimuli)
4 months: Infants can smoothly track slow-moving objects
8 months: Adult-like visual scanning
- Smoothly follow a moving object
Improved scanning is due to brain maturation
Visual scanning allows infants to control what they observe and learn

Face Perception

Why are babies so drawn to faces?
- Newborns and adults both have a preference for faces and face-like stimuli
Hypothesis: Is there a special innate mechanism for face perception present at birth?

Perceptual Constancy in Infants

Study: Habituation paradigm with newborns
- Habituation: Show an infant a small black and white cube at various distances in each trial
- Question: Do infants perceive these as the same object or different objects?
- Test: Show the original small cube and a larger, identical cube
  - The larger cube is presented further away to create the same size retinal image
- Results: Infants looked longer at the larger cube
  - This indicates that the larger cube was perceived as a novel stimulus
- This suggests from birth, infants can see the same object at multiple distances, meaning they demonstrate perceptual constancy
  - They see the repeated presentations of the smaller cube as consistent in size

Object Segregation

Ability to identify objects that are separate from each other
- To determine borders between distinct objects
Movement is an important cue for this
- Separate objects move independently of each other
Color is another important cue
- Different colors often indicate different objects

Object Segregation in Infants

Habituation paradigm with newborns and 4-month olds
Habituation: Show infants a video of a rod moving back and forth behind a box
- Question: Do infants see the rod as one long rod or two separate short rods?
Test: Show infants a complete rod and a broken, shorter rod that are both moving.
Results:
- 4-month olds looked longer at the broken rod
  - This means they understood that the rod behind the box was one object
- Newborns looked for about the same amount of time at both rods.
  - They did not understand the continuous nature of the rod behind the box.
This suggests that object segregation is not innate
It is learned with experience, relying on improved visual scanning

Depth Perception

Binocular disparity: The difference between the retinal image of an object in each eye
- This creates two slightly different signals sent to the brain
The visual cortex combines these different neural signals caused by binocular disparity
At 4 months old, infants show depth perception based on binocular disparity

Sensitive Period for Binocular Vision

Sensitive period: A biological period where certain experiences are necessary for normal development of a skill.
Binocular vision sensitive period: Birth to age 3
- Depth perception from binocular disparity develops naturally with brain maturation
  - As long as a child receives normal visual input from both eyes
- If an infant does not receive normal binocular visual input until age 3 they may fail to develop normal binocular vision
  - They may have life-long difficulties with depth perception
Monocular depth cues: Depth cues perceived with one eye
- Relative size and overlap
- Perceived at 6 months old
- Assessed using the visual cliff
  - 6-month-olds won't crawl over the visual cliff
  - Younger infants will
- This suggests that this aspect of depth perception needs to be developed through experience, which relies on improved visual acuity

Visual Development Timeline

Birth
- Rudimentary visual scanning, poor acuity, preference for high contrast, grayscale, preference for faces over non-faces, and perceptual constancy present
2 months
- Color vision emerges
4 months
- Object segregation, binocular depth perception appears
- Binocular vision sensitive period is from birth to age 3
5 months
- Adult-like color perception
6 months
- Face generalists, monocular depth perception appears
8 months
- Adult-like visual scanning and visual acuity
9 months
- Face specialists

Nature vs. Nurture of Visual Development

Innate: Perceptual constancy, preference for top-heavy stimuli
Improves with brain maturation: Visual acuity, color perception, visual scanning
Experience-dependent: Object segregation, face perception, depth perception

Review of Visual Development

Preferential looking paradigm: Infants prefer more interesting and complex visual stimuli
Habituation paradigm: Infants prefer novel stimuli after habituation

Familiarity vs. Novelty

Infants prefer to look at stimuli that are complex, saturated, and familiar
Familiarity can be considered in two ways:
- "Natural" familiarity: Stimuli infants experience frequently in their lives
- "Lab-induced" familiarity: Familiarize an infant to a new stimulus by briefly exposing them
  - This involves showing a stimulus for just long enough for familiarity to set in without boredom

Intermodal Perception

Coordinated perception of a single object or event through two or more sensory systems
- Often vision and at least one other sensory modality
- We rely heavily on vision
Present very early in development
- Combine vision and touch
- Study with newborns familiarized with a pacifier they couldn't see
  - The test pacifier was bumpy or spiky (not harmful)
- Newborns were then presented with images of both pacifiers
- Results: Newborns showed preferential looking for the familiar stimulus
  - The bumpy or spiky pacifier
- This demonstrates the ability to combine visual information with touch from birth
- Combine vision and auditory information
  - Study: 4-month olds were simultaneously shown two videos side by side
    - Video 1: Someone plays peekaboo
    - Video 2: Someone plays the drums
  - Babies hear someone say "peekaboo"
    - No drum noises
  - Results: Infants looked longer at the video of the person playing peekaboo
  - Infants can integrate visual and auditory information
  - Important for language development because children need to understand that speech sounds are linked with moving mouths

Categorization in Infancy

Categorization is present from as young as 3 months old
Study: Habituation paradigm with cats
- Show babies photos of cats
- Test phase shows a photo of a dog
- Results: Babies look longer at the dog
Infants can form more general categories
- Study: 6-month-old infants were shown photos of mammals
  - Test phase shows a non-mammal
  - Infants looked longer at the non-mammal
    - Demonstrates ability to discriminate between mammals and non-mammals

Perceptual Categorization

Infants group things together that are similar in appearance
- Especially objects with similar shapes
- Study with 6-12 month olds:
  - Show infants a target object and reveal that it rattles.
  - Infants are then more likely to assume a different object with similar shapes also rattles (fun/unexpected)
  - This also applies to texture and color (but more heavily based on shape)
Limitations to perceptual categorization
- Difficulty with exceptions
  - Animals without legs
- Can mistakenly categorize objects together
  - Planes are birds

Conceptual Categorization

Around 9 months old
Children begin to categorize objects based on shared function or behavior
- Still mostly categorize based on perceptual similarities
At 9 months old, infants categorize these three general categories:
- People
- Animals
- Inanimate objects
Indexed by different reactions to members of each category
- Infants will smile and be more interested in people > animals > objects

Importance of Categorization

Simplifies the world
Allows children to make inferences and predictions about objects in the same category
Influences the questions children will ask about objects

Beyond Infancy

2-3 years old: Children start to form category hierarchies
Category hierarchies: Organize object categories by set-subset relations
- Allow for finer distinctions among objects within a category
From highest to lowest
- Superordinate level: Animals, plants, furniture, etc.
- Basic level: Chairs, tables, cats, dogs, etc.
- Subordinate level: Lions, lynxes, etc.

Category Hierarchies

Basic level first
- Objects at this level have the most obvious similarities
- Superordinate differences are too broad and subordinate differences are too fine for children to understand at this age
  - This makes basic level the more logical starting point

Motor Milestones

Reflexes: Innate involuntary actions that occur in response to particular stimulation
- Reflexes are adaptive
Reflexes examples
- Grasping: Put something near an infant's palm and they'll close their hand around it
- Rooting and sucking: Place an object to the side of an infant's face, they will turn toward it and suck it
- Stepping: If you hold a baby up, they will try to step on the ground.
The function of some reflexes is unclear
- Tonic neck reflex: When an infant's head turns, the arm on that side will extend, and the arm on the other side will flex
  - The reason this reflex exists is unclear
Most reflexes disappear by the age of 2 months
- Some remain
  - Coughing, sneezing, blinking, and withdrawing from pain
The absence of reflexes or those that persist too long can indicate neurological problems

Motor Milestones in Infancy

Major motor developmental tasks of a period
- They happen in a sequence, rarely out of order
- Lots of variation in the age when these milestones are achieved
General order:
- Lift head: 1 month
- Prop themselves up: 2-4 months
- Rolling over: 2-5 months
- Support weight with legs: 3.5-6 months
- Sit without support: 4.5-8 months
- Stand with support: 5-10 months
- Pull themselves to stand: 6-10 months
- Walk using furniture for support: 7-13 months
- Stand alone (easily): 10-14 months
- Walks alone (easily): 11-14 months
What about crawling?

Crawling

Crawling typically begins around 7-8 months old.
Crawling styles vary greatly between babies.
Crawling is not considered a motor milestone because many healthy babies skip it.
Babies may skip crawling due to upper body or core weakness, hypersensitivity to floor texture, or insufficient time on the floor.

Cultural Differences in Motor Development

Average ages for motor milestones are based on WEIRD samples (Western, educated, industrialized, rich, and democratic).
Only 15% of the world's population is WEIRD, meaning most people are not from these areas.

Example 1: Culture and Sitting

The normal age for sitting independently is 4.5 to 8 months old.
There are significant cultural differences in how long 5-month-olds can sit independently.
- Italian infants rarely sat alone.
- American infants sat independently for a few minutes.
- Kenyan infants sat independently for over 20 minutes.
These differences are influenced by the type of surfaces infants are placed on:
- Infants placed on surfaces with little postural support (ground, adult furniture) need to build core strength to sit independently.
- Infants placed on surfaces with lots of postural support (child furniture, being held by an adult) do not need to overcome gravity as much.
Infants who spend more time on surfaces with less postural support tend to sit independently earlier.

Example 2: Culture and Encouragement of Motor Skills

The opportunities infants have to practice motor skills and the encouragement they receive affects motor development.
Some cultures actively discourage crawling due to safety or health concerns.
Motor exercises are encouraged in some cultures, like Sub-Saharan Africa.

Example 3: Culture, Diapers, and Walking

Diapers impact infant walking.
Infants walk more maturely when naked compared to wearing diapers.
Cloth diapers have the least mature walking ability.

Implications of Cultural Differences

Context plays a significant role in motor development.
Variations in the course of development reflect the environment infants are in.

Mechanisms Behind Motor Development

Motor development involves a complex interplay of factors, including:
- Brain maturation
- Increases in physical strength
- Physical abilities like posture control and balance
- Perceptual skills
- Changes in body proportions and weight
- Motivation
These factors contribute to individual differences in motor development.

Role of Weight Changes

Infants are born with a stepping reflex.
This reflex disappears around 2 months old.
The reflex reappears between 7-12 months of age when learning to walk (average is 11 months).
The disappearance of the reflex is partly due to weight gain.

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Description

This quiz explores the milestones in visual acuity and perception among infants. Test your knowledge on the development of color vision, visual tracking, and the significance of stimuli preference in early childhood. Learn about key studies and theories that elucidate how infants perceive and interpret their surroundings.