Perceptual Development in Infancy: Methods, Abilities, and Theories

Perceptual Development in Infancy

Studying Perceptual Development

Researchers use specialized methods to investigate how infants perceive their environment, as infants cannot verbally communicate their experiences. These methods allow psychologists to infer perceptual abilities and preferences in early development.

• Preference Technique: Developed by Robert Fantz (1956), this method involves showing infants two pictures and measuring how long they look at each. Longer looking times indicate preference or discrimination between stimuli.

• Habituation: Repeated exposure to a stimulus leads to decreased attention, indicating the infant has become familiar with it.

• Dishabituation: When a new stimulus is presented, renewed attention suggests the infant perceives it as different from the familiar one.

• Operant Conditioning: Infants are trained to respond to a stimulus (e.g., sucking, head turning) to receive a reward, revealing their ability to discriminate between stimuli.

Example: An infant shown a checkerboard pattern and a plain field may look longer at the checkerboard, indicating pattern discrimination.

Development of Visual Perception

Visual perception in infants develops rapidly, enabling them to interpret and interact with their environment. Key questions include whether infants perceive their surroundings as adults do and whether they can judge distances.

Depth Perception

• Essential for navigating the environment and performing basic motor skills.

• Infants use three main types of cues to judge depth:

  • Binocular cues: Information from both eyes, such as retinal disparity.

  • Monocular cues: Information from one eye, including interposition (overlapping objects) and linear perspective (converging lines).

  • Kinetic cues: Motion-based cues, such as objects moving closer or farther away.

Studies of Infants’ Depth Perception

• Kinetic cues are used first, by 3 to 4 months of age.

• Binocular cues develop around 4 months.

• Monocular cues (including interposition and linear perspective) appear around 5 to 7 months.

• Visual Cliff Experiment (Gibson & Walk, 1960): A glass table with a patterned surface creates the illusion of a "cliff." Infants with depth perception are reluctant to cross the apparent drop, indicating their ability to perceive depth.

Example: An infant crawling on the visual cliff will stop at the edge if they perceive the drop, demonstrating depth perception.

Perception of Patterns

Infants' visual attention is initially guided by the search for patterns. Over the first few months, their focus shifts from the location of objects to their identity and relationships.

• In the first 2 months, infants are attracted to high-contrast patterns.

• By 2 to 3 months, attention shifts to recognizing what objects are.

• Habituation Procedures (Albert & Rose Caron, 1981): Infants are shown a series of related pictures until they lose interest, then shown a new picture to test for recognition of patterns or relationships.

Auditory Perception in Infants

Infants possess advanced auditory discrimination abilities, allowing them to distinguish between subtle differences in sounds and voices.

• Can discriminate between similar speech sounds (e.g., "pa" vs. "ba").

• Show preference for patterns in sounds.

• Newborns can recognize individual voices and prefer their mother's voice over others.

• Infants are sometimes better than adults at distinguishing certain speech contrasts.

Example: A newborn will turn its head toward its mother's voice, indicating recognition and preference.

Intermodal Perception

Intermodal perception refers to the ability to integrate information from multiple senses, such as sight and sound. This ability emerges early in infancy and is crucial for learning.

• Possible as early as the second day of life (e.g., matching mother's face and voice).

• Older infants can connect auditory and visual information (e.g., matching a sound to a moving object).

• Elizabeth Spelke (1979) found that 4-month-olds can connect sound with movement.

Theories of Perceptual Development

There are two main theoretical perspectives on how perceptual abilities develop in infancy:

• Nativist View: Most perceptual abilities are innate and present at birth.

• Empiricist View: Perceptual abilities are learned through experience and interaction with the environment.

• Current evidence suggests that while many skills are present at birth, experience is necessary for full development.

Chapter Summary

• The nervous system undergoes rapid changes in the first two years, with peak development of dendrites and synapses between 12 and 24 months, followed by synaptic pruning and myelination.

• Motor skills progress from creeping to crawling, walking, and running as muscles and lungs strengthen.

• Breastfeeding is generally superior to formula feeding for infant health.

• Malnutrition can be macronutrient (caloric deficiency) or micronutrient (lack of vitamins/minerals).

• Regular checkups and immunizations are essential; SIDS is the leading cause of death between 1 month and 1 year.

• Color vision is present at birth, but visual acuity and tracking improve with age; auditory, smell, taste, touch, and motion senses are well developed.

• Infants can discriminate faces and voices, especially those of their mothers, and can transfer learning across senses (intermodal perception).

• Both innate abilities and experience contribute to perceptual development.

Theory	Main Claim	Evidence
Nativist	Perceptual abilities are inborn	Many skills present in newborns
Empiricist	Perceptual abilities are learned	Experience is necessary for full development

Additional info: The notes above integrate both the provided slides and academic context to ensure a comprehensive, exam-ready summary of perceptual development in infancy, suitable for college-level psychology students.