general psychology module 17
figure-ground
the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
grouping
the perceptual tendency to organize stimuli into coherent groups
the amplitude of a light wave determines our perception of A: brightness B: color C: meaning D: distance
Answer: A
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
Answer: B
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
Answer: B
perceiving a tomato as consistently red, despite lighting shifts, is an example of A: shape constancy B: perceptual constancy C: binocular cue D: continuity
Answer: B
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
Answer: B
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
Answer: C
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
Answer: C
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
Answer: C
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
Answer: C
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
Answer: D
Two examples of _______________ depth cues are interposition and linear perspective
Monocular
retinal disparity
a binocular cue for perceiving depth. By comparing retinal images from the two eyes, the brain computes distance-the greater the disparity (difference) between the two images, the closer the object
monocular cue
a depth cue, such as interposition or linear perspective, available to either eye alone
binocular cue
a depth cue, such as retinal disparity, that depends on the use of two eyes
visual cliff
a laboratory device for testing depth perception in infants and young animals
how do we perceive color in the world around us?
according to the young-helmholtz trichcromatic (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 v green, blue v yellow, black v 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
phi phenomenon
an illusion of movement created when two or more adjacent lights blink on and off in quick succession
gestalt
an organized whole. Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes
transduction
conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.
How do we use binocular and monocular cues to perceive the world 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 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, 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.
the cells in the visual cortex that respond to certain lines, edges, and angles are called
feature detectors
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 as distinct from its surroundings. We bring order and form to stimuli by organizing them into meaningful groups, following such rules as proximity, continuity, and closure.
parallel processing
processing many aspects of a stimulus or problem at once
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.
feature detectors
nerve cells in the brain's visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement
what mental processes allow you to perceive a lemon as yellow?
opponent-processes
the brain's ability to process many aspects of an object or a problem simultaneously is called
parallel-processing
perceptual constancy
perceiving objects as unchanging (having consistent color, brightness, shape, and size) even as illumination and retinal images change
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
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
cones
retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. Cones detect fine detail and give rise to color sensations.
rods
retinal receptors that detect black, white, and gray, and are sensitive to movement; necessary for peripheral and twilight vision, when cones don't respond
perceptual adaptation
the ability to adjust to changed sensory input, including an artificially displaced or even inverted visual field
depth perception
the ability to see objects in three dimensions although the images that strike the retina are two dimensional; allows us to judge distance
intensity
the amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness. Intensity is determined by the wave's amplitude (height).
fovea
the central focal point in the retina, around which the eye's cones cluster
hue
the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so fourth
wavelength
the distance from the peak of one light wave or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short gamma waves to the long pulses of radio transmission.
the characteristic of light that determines the color we experience, such as blue or green, is__________________
the electromagnetic spectrum
retina
the light-sensitive inner surface of the eye, containing the receptor rods, and cones plus layers of neurons that begin the processing of visual information
optic nerve
the nerve that carries neural impulses from the eye to the brain
blind spot
the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there.
accommodation
the process by which the eye's lens changes shape to focus near or far objects on the retina
opponent-process theory
the theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.
young-helmholtz trichromatic (threecolor) theory
the theory that the retina contains three different types of color receptors-one most sensitive to red, one to green, one to blue-which, when stimulated in combination, can produce the perception of any color.
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.
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 it's wavelength, and it's brightness depends on its intensity
