Module 19 REVIEW

• 19-1 How did the Gestalt psychologists understand perceptual organization, and how do figure-ground and grouping principles contribute to our perceptions?

• Gestalt psychologists searched for rules by which the brain organizes fragments of sensory data into gestalts (from the German word for “whole”), or meaningful forms. In pointing out that the whole may exceed the sum of its parts, they noted that we filter sensory information and construct our perceptions.
• To recognize an object, we must first perceive it (see it as a figure) as distinct from its surroundings (the ground). We bring order and form to stimuli by organizing them into meaningful groups, following such rules as proximity, continuity, and closure.

• 19-2 How do we use binocular and monocular cues to see in three dimensions, and how do we perceive motion?

• Depth perception is our ability to see objects in three dimensions and judge distance. The visual cliff and other research demonstrate that many species naturally perceive the world in three dimensions at, or very soon after, birth.
• Binocular cues, such as retinal disparity, are depth cues that rely on information from both eyes.
• Monocular cues (such as relative size, interposition, relative height, relative motion, linear perspective, and light and shadow) let us judge depth using information transmitted by only one eye.
• As objects move, we assume that shrinking objects are retreating and enlarging objects are approaching.
• A quick succession of images on the retina can create an illusion of movement, as in stroboscopic movement (experienced when viewing filmed images) and the phi phenomenon (when we perceive movement between blinking lights).

• 19-3 How do perceptual constancies help us construct meaningful perceptions?

• Perceptual constancy enables us to perceive objects as stable despite the changing image they cast on our retinas.
• Color constancy is our ability to perceive consistent color in objects, even though the lighting and wavelengths shift.
• Brightness (or lightness) constancy is our ability to perceive an object as having a constant lightness even when its illumination—the light cast upon it—changes.
• Our brain constructs our experience of an object’s color or brightness through comparisons with other surrounding objects.
• Shape constancy is our ability to perceive familiar objects (such as an opening door) as unchanging in shape.
• Size constancy is perceiving objects as unchanging in size despite their changing retinal images.
• Knowing an object’s size gives us clues to its distance; knowing its distance gives clues about its size, but we sometimes misread monocular distance cues and reach the wrong conclusions, as in the Moon illusion.

• 19-4 What does research on restored vision, sensory restriction, and perceptual adaptation reveal about the effects of experience on perception?

• Experience guides our perceptual interpretations. People blind from birth who gained sight after surgery lack the experience to visually recognize shapes and forms.
• Sensory restriction research indicates that there is a critical period for some aspects of sensory and perceptual development. Without early stimulation, the brain’s neural organization does not develop normally.
• People given glasses that shift the world slightly to the left or right, or even upside down, experience perceptual adaptation. They are initially disoriented, but they manage to adapt to their new context.

Multiple-Choice Questions

1. A teacher used distortion goggles, which shifted the wearer’s gaze 20 degrees, to demonstrate an altered perception. A student wearing the goggles initially bumped into numerous desks and chairs while walking around, but after 30 minutes of wearing the goggles was able to smoothly avoid obstacles, illustrating the concept of
   1. perceptual adaptation.
   2. visual interpretation.
   3. sensory adaptation.
   4. perceptual constancy.
   5. binocular cues.
2. What do we call the illusion of movement that results from two or more stationary, adjacent lights blinking on and off in quick succession?
   1. Phi phenomenon
   2. Perceptual constancy
   3. Binocular cues
   4. Retinal disparity
   5. Stroboscopic movement
3. Bryanna and Charles are in a dancing competition. It is easy for spectators to see them against the dance floor because of
   1. the visual cliff.
   2. the phi phenomenon.
   3. color constancy.
   4. sensory restriction.
   5. figure-ground relationships.
4. Narmeen is viewing the board in the classroom. She knows that the board is located far away because the view from her left eye is slightly different than the view from her right eye. Her ability to judge the distance of the board is due to which depth cue?
   1. Retinal disparity
   2. Relative size
   3. Linear perspective
   4. Relative motion
   5. Convergence
5. Which of the following statements is best explained by research on depth perception using the visual cliff?
   1. Binocular depth cues develop before monocular depth cues.
   2. Monocular depth cues develop before binocular depth cues.
   3. Human infants are born with an innate sense of depth.
   4. Human infants must learn to perceive depth.
   5. Humans do not develop the perception of depth until 24 months of age.
6. Even though the banana seemed to change color as the lighting in the room changed, Jane knew that the color of the banana was not actually changing. This is due to
   1. perceptual adaptation.
   2. convergence.
   3. color constancy.
   4. interposition.
   5. relative luminance.

Practice FRQs

1. Look at the relative size cartoon in Figure 19.6. Describe how the artist incorporated relative size, linear perspective, and interposition to create depth.

Answer

Specific explanations may utilize different aspects of the cartoon.

1 point: Relative size: We know that the woman is closer to us than the police officer because she is drawn larger, or we know that the police officer is farther away because he is drawn smaller. Page 191

1 point: Linear perspective: We can tell that the sidewalk is receding into the distance because its sides pinch closer together in the background of the image. Page 191

1 point: Interposition: We know the woman is closer to us than the police officer because our view of her partially blocks our view of him, or we know the green car is farther away because it is being blocked by the lamp post. Page 191

2. Imagine that you attend a sporting event at your school. Explain how the following terms affect your perception of the game:
   • Gestalt
   • Proximity
   • Interposition

(3 points)