| A | B |
|---|
| the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. | sensation |
| the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events. | perception |
| analysis that begins with the sense receptors and works up to the brain’s integration of our sensory information. | bottom-up processing |
| information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations. | top-down processing |
| the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them | psychophysics |
| the minimum stimulation needed to detect a particular stimulus 50% of the time | absolute threshold |
| a theory predicting how and when we detect the presence of a faint stimulus (“signal”) amid background stimulation(“noise”) | signal detection theory |
| below one’s absolute threshold for conscious awareness | sublimial |
| the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response | priming |
| the minimum difference between two stimuli required for detection 50% of the time. | difference threshold |
| the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount) | Weber's Law |
| diminished sensitivity as a consequence of constant stimulation | sensory adaptation |
| conversion of one form of energy into another. In sensation, the transforming of stimulus energies into neural impulses. | transduction |
| the distance from the peak of one light or sound wave to the peak of the next | wavelength |
| the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth | hue |
| the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude | intensity |
| the adjustable opening in the center of the eye through which light enters. | pupil |
| a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening | iris |
| the transparent structure behind the pupil that changes the shape to help focus images on the retina | lens |
| the process by which the eye’s lens changes shape to focus near or far objects on the retina | accomodation |
| 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 | retina |
| the sharpness of vision | acuity |
| a condition in which nearby objects are seen more clearly than distance objects because distant objects focus in front of the retina | nearsightedness |
| a condition in which faraway objects are seen more clearly than nearby objects because the image of near objects is focused behind the retina | farsightedness |
| retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don’t respond. | rods |
| receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. Detect fine detail and give rise to color sensations. | cones |
| the nerve that carries neural impulses from the eye to the brain. | optic nerve |
| the point at which the optic nerve leaves the eye. | blind spot |
| the central focal point in the retina, around which the eye’s cones cluster. | fovea |
| the processing of several aspects of a problem simultaneously; the brain’s natural mode of information processing for many functions, including vision. Contrasts with the step-by-step processing of most computers and of conscious problem solving. | parallel processing |
| the theory that the retina contains three different 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. | Young-Helmholtz trichomatic theory |
| the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. | opponent process theory |
| perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object | color constancy |
