Chapter 6 Multiple Choice (section 2)

The amplitude of a light wave determines our perception of A. brightness. B. color. C. meaning. D. distance.

A. brightness.

In listening to a concert, you attend to the solo instrument and perceive the orchestra as accompaniment. This illustrates the organizing principle of A. figure-ground. B. shape constancy. C. grouping. D. depth perception.

A. figure-ground.

How do we perceive color in the world around us?

According to the Young-Helmholtz trichromatic (three-color) theory, the retina contains three types of color receptors. Contemporary research has found three types of cones, each most sensitive to the wavelengths of one of the three primary colors of light (red, green, or blue). According to Hering's opponent-process theory, there are three additional color processes (red-versus-green, blue-versus-yellow, black-versus-white). Research has confirmed that, en route to the brain, neurons in the retina and the thalamus code the color-related information from the cones into pairs of opponent colors. These two theories, and the research supporting them, show that color processing occurs in two stages.

The visual cliff experiments suggest that A. infants have not yet developed depth perception. B. crawling human infants and very young animals perceive depth. C. we have no way of knowing whether infants can perceive depth. D. unlike other species, humans are able to perceive depth in infancy.

B. crawling human infants and very young animals perceive depth.

Perceiving a tomato as consistently red, despite lighting shifts, is an example of A. shape constancy. B. perceptual constancy. C. a binocular cue. D. continuity.

B. perceptual constancy.

After surgery to restore vision, adults who had been blind from birth had difficulty A. recognizing objects by touch. B. recognizing objects by sight. C. distinguishing figure from ground. D. distinguishing between bright and dim light.

B. recognizing objects by sight.

Cones are the eye's receptor cells that are especially sensitive to _________ light and are responsible for our vision_________. A. bright; black-and-white B. dim; color C. bright; color D. dim; black-and-white

C. bright; color

Depth perception underlies our ability to A. group similar items in a gestalt. B. perceive objects as having a constant shape or form. C. judge distances. D. fill in the gaps in a figure.

C. judge distances.

The blind spot in your retina is located where A. there are rods but no cones. B. there are cones but no rods. C. the optic nerve leaves the eye. D. the bipolar cells meet the ganglion cells.

C. the optic nerve leaves the eye.

Our tendencies to fill in the gaps and to perceive a pattern as continuous are two different examples of the organizing principle called A. interposition. B. depth perception. C. shape constancy. D. grouping.

D. grouping.

Two theories together account for color vision. The Young-Helmholtz trichromatic theory shows that the eye contains__________ , and Hering's theory accounts for the nervous system's having__________ . A. opposing retinal processes; three pairs of color receptors B. opponent-process cells; three types of color receptors C. three pairs of color receptors; opposing retinal processes D. three types of color receptors; opponent-process cells

D. three types of color receptors; opponent-process cells

How do we use binocular and monocular cues to see the world in three dimensions?

Depth perception is our ability to see objects in three dimensions and judge distance. The visual cliff and other research demonstrate that many species 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 height, relative size, interposition, 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. The brain computes motion imperfectly, with young children especially at risk of incorrectly perceiving approaching hazards such as vehicles. A quick succession of images on the retina can create an illusion of movement, as in stroboscopic movement or the phi phenomenon.

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.

Where are feature detectors located, and what do they do?

Feature detectors, specialized nerve cells in the visual cortex, respond to specific features of the visual stimulus, such as shape, angle, or movement. Feature detectors pass information on to other cortical areas, where supercell clusters respond to more complex patterns.

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, 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.

How do the rods and cones process information, and what is the path information travels from the eye to the brain?

Light entering the eye triggers chemical changes that convert light energy into neural impulses. Cones and rods at the back of the retina each provide a special sensitivity—cones to detail and color, rods to faint light and peripheral motion. After processing by bipolar and ganglion cells, neural impulses travel from the retina through the optic nerve to the thalamus, and on to the visual cortex.

How do perceptual constancies help us construct meaningful perceptions?

Perceptual constancies, such as in color, brightness (or lightness), shape, or size, enable us to perceive objects as stable despite the changing image they cast on our retinas. Our brain constructs our experience of an object's color or brightness through comparisons with other surrounding objects. 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.

How does the brain use parallel processing to construct visual perceptions?

Through parallel processing, the brain handles many aspects of vision (color, movement, form, and depth) simultaneously. Other neural teams integrate the results, comparing them with stored information and enabling perceptions.

The characteristic of light that determines the color we experience, such as blue or green, is____________ .

WaveLength

What are the characteristics of the energy that we see as visible light? What structures in the eye help focus that energy?

What we see as light is only a thin slice of the broad spectrum of electromagnetic energy. The portion visible to humans extends from the blue-violet to the red light wavelengths. After entering the eye through the cornea, passing through the pupil and iris, and being focused by a lens, light energy particles strike the eye's inner surface, the retina. The hue we perceive in a light depends on its wavelength, and its brightness depends on its intensity.

What mental processes allow you to perceive a lemon as yellow?

Your brain constructs this perception of color in two stages. In the first stage, the lemon reflects light energy into your eyes, where it is transformed into neural messages. Three sets of cones, each sensitive to a different light frequency (red, blue, and green) process color. In this case, the light energy stimulates both red-sensitive and green-sensitive cones. In the second stage, opponent-process cells sensitive to paired opposites of color (red/green, yellow/blue, and black/white) evaluate the incoming neural messages as they pass through your optic nerve to the thalamus and visual cortex. When the yellow-sensitive opponent-process cells are stimulated, you identify the lemon as yellow.

The cells in the visual cortex that respond to certain lines, edges, and angles are called _______________ _______________ .

feature detectors.

Two examples of _________ depth cues are interposition and linear perspective.

monocular.

The brain's ability to process many aspects of an object or a problem simultaneously is called ______________ ______________ .

parallel processing.

In experiments, people have worn glasses that turned their visual fields upside down. After a period of adjustment, they learned to function quite well. This ability is called __________.

perceptual adaptation.