1. Perceptual Development
Lecture Outline
Perceptual Development
Methods
Vision
Acuity and Color Vision
Pattern Perception
Object Perception
Depth Perception
Intermodal Perception

2. Fantz’s Experiment on Infants’ Visual Perception
Figure 5.14
Photo: © David Linton

3. Habituation: Gradual decrease in the strength of a response due to repetitive stimulation
Ex: looking

4. Habituation and Dishabituation
Figure 6.5
From Slater, A., Morison, V. & Somers, M., 1988, “Orientation Discrimination and Cortical Functions in the Human Newborn,” Perception, Vol. 17, pp , Fig. 1 and Table 1. Reprinted by permission of Pion, London.

5. Visual acuity: Sharpness of visual discrimination

6. Development of Visual Acuity: Newborn: 20/400-20/800
By 6-8 months, close to a normal adult’s vision (20/20)
Visual system continues to develop for several years

7. By 2 or 3 months, color vision is similar to adults
Newborns:
Don’t see full range of colors
Seem to distinguish white or gray from some colors
By 2 or 3 months, color vision is similar to adults

8. Pattern Perception
Contrast Sensitivity: Ability to detect differences in light and dark areas in a visual pattern

11. Object Segregation: Perception of the boundaries between objects

13. Development of Object Segregation:
 Infants under 6 months use motion and physical location to differentiate objects
After 6 months, begin to use shape, texture, and color (stationary cues) to differentiate objects (similar to adults)

14. Depth perception: Ability to judge the distance of objects from one another and from one’s self.

15. Kinetic Depth Cues (Optical Expansion)
Related to motion
Ex: “Defensive” blinking when object moves toward baby
Used by 1-month-olds

16. Binocular Depth Cues
Each eye receives a slightly different view of the visual field
Retinal images are combined by the visual cortex to create the perception of depth (stereopsis)

17. Develops around 4 months of age
Guides reaching behavior

18. Pictorial ( or Monocular) Depth Cues
Used in pictures to create an illusion of 3 dimensions
Exs: relative size; interposition

20. Used by 7-month-old infants (but not 5-month-olds)

21. Intermodal Perception: Integration of sensory information from two or more sensory systems