Infant Visual Perception

Infant Visual Perception

QUESTIONS?

Some suggested topics...

1) What do you think the adaptive significance of having infants have this strong preference for faces and eyes is?

2) What do you think would happen if a baby, who couldn’t open their eyes for the first few years of their life, suddenly opened them?

3) Why do you think perceptual narrowing occurs? Why do you think they lose the capacity to discriminate species, races, etc.?

- (debate: why perceptual narrowing is good/ not good)

Jessica Szorenyi and Brent Robinson

Our visual perception is

still developing...

Newborn

Newborn Vision Continued...

8 Weeks

6 Months

• Acuity fully developed by age 6.
• Cones for colour and sharp acuity, rods for light contrast.
• Newborn cones 350 times less sensitive to light. (Kellman & Banks, 1998)
• Can see colour fully by 4 months.

Age 6

tinyeyes.com

METHODOLOGIES

How can we tell what an infant can see?

Vision in the Newborn

VS

Development of Visual Preferences

*Use behaviour that an infant can control*

• Can see light --- pupillary reflex
• Little accommodation of the lens
• By 3 months, accommodation is at adult level
• Convergence and coordination fully developed by 6 months
• Vision ranges from 20/400 – 20/600 (Slater,1995)

The Other-Race Effect

-Most basic method: Head Turn

-Many limitations...

• newborns are not good at facial discrimination but 3-9 month-olds are.
• 'Other-race effect' - 3 month-olds don't show it, 9 month-olds do.
• Familiarity plays a huge role in shaping infants' visual perception.
• Infants lose diversity, but gain expertise.

Using Infant Sucking to Provide Insight into Infant Perception

Anthony DeCasper and Melanie Spence (1986)

-Testing newborns

• 2-4 months - pay attention to physical properties
• Later - influenced by psychological aspects

Preference for

Attractive Faces

Visual Preference Paradigm

Robert Fantz (1958, 1961)

-Infants younger than 1 week can tell the difference between certain stimuli and prefer to look at faces

• Judith Langlois et al. (1987) -2/3 of Babies prefer to look at attractive faces.
• Slater et al. (1998) -Preference for attractive faces across races, gender, and age.
• Gangestad & Thornhill (1997) -Attractiveness based on vertical symmetry.
• 'Average' facial features most appealing
• Halberstadt & Rhodes (2000) -Average bias for dogs, birds, and wristwatches.

Physical Stimulus Characteristics

• Marshal Haith (1966) - Infants prefer a moving stimulus
• Philip Salapetek and William Kessen (1966) - Infants are attracted to areas of high contrast and contours of objects - By 2 months of age, infants use the externality effect

The Visual Cliff

Face Processing...

Gibson, E. J., & Walk, R. D. (1960). The" visual cliff". WH Freeman Company.

• Crawling babies had developed the ability to perceive depth

• Gava et al. (2008) -Infants pay special attention to open eyes and have specific preferences

Visual System Prior to Birth

Habituation/ Dishabituation Paradigm

Steven Friedman (1972)

1 to 3-day-old infants demonstrated habituation/dishabituation to visual stimuli

Physical Characteristics...

• 4 month old infants prefer symmetrical vertical forms
• 3 and 4 month old infants prefer curvature

Development of Face Processing

• Extremely weak
• Week ~24~ eyes are open and blinking
• Week ~28~ differentiate between light and dark
• One week prior to birth ~ track a light source and turn towards light

• Born with notion of faceness
• Teresa Farroni et al. (2002) -Infants are attentive to eye gaze

The Violation of Expectation Paradigm

Baillargeon, R., Spelke, E. S., & Wasserman, S. (1985). Object Permanence in five-month-old infants. Cognition, 20(3), 191-208.

Psychological Stimulus Characteristics

• Perception of familiarity and novelty requires memory Beginning at ~2 months SCHEMAS are formed (Kagan, 1971)
• Discrepancy principle (Kagan, 1971) (McCall, Kennedy, & Appelbaum, 1977)

• Young infants prefer familiar stimuli, then prefer novel stimuli once they have developed a base of memory representations. (Rose et al., 1982) (Courage & How, 1998) (Bogartz & Shinskey, 1998) (Bahrick & Pickens 1995)