| A | B |
|---|
| sensation | the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment |
| bottom up processing | analysis that begins with the sense receptors and works up to the brain's integration of sensory information |
| top down processing | information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations |
| psychophysics | the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them. |
| absolute threshold | the minimum stimulation needed to detect a particular stimulus 50 percent of the time |
| signal detection theory | predicts how and when we detect the presence of a faint stimulus ("signal") amid background stimulation ("noise"). Assumes that there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and level of fatigue |
| subliminal | below one's absolute threshold for conscious awareness |
| difference threshold | the minimum difference that a person can detect between two stimuli. We experience the difference threshold as a just noticeable difference (aka jnd) |
| Weber's Law | the principle that, to perceive their difference, two stimuli must differ by a constant minimum percentage (rather than a constant amount) |
| sensory adaptation | diminished sensitivity as a consequence of constant stimulation |
| transduction | conversion of one form of energy into another. In sensation, the transforming of stimulus energies into neural impulses |
| wavelength | the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission |
| hue | the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth |
| intensity | the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude |
| pupil | the adjustable opening in the center of the eye through which light enters |
| iris | a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening |
| lens | the transparent structure behind the pupil that changes shape to focus images on the retina |
| accommodation | the process by which the eye's lens changes shape to focus the image of near objects on the retina |
| 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 |
| acuity | the sharpness of vision |
| nearsightedness | a condition in which nearby objects are seen more clearly than distant objects because the lens focuses the image of distance objects in front of the retina |
| farsightedness | a condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina |
| rods | retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond |
| cones | receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations. |
| optic nerve | the nerve that carries neural impulses form 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 |
| fovea | the central focal point in the retina, around which the eye's cones cluster |
| parallel processing | 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 (serial) processing of most computers and of conscious problem solving. |
| Trichromatic Theory | the theory that the retina contains three different color receptors--one most sensitive to red, one to green, and one to blue--which when stimulated in combination can produce the perception of any color |
| opponent process theory | the theory that opposing retinal processes (red-green, yellow-blue, 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. |
| color constancy | perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object |
| Stroboscopic Movement | A Rapid series of slightly differing still images gives the impression of movement. |
| Phi Phenomenon | 2 adjacent stationary lights blink on and off in quick succession, we perceive a single light moving. |
| Feature Detectors | Nerve cells in the visual cortex respond to specific features, such as edges, angles, and movement. |
| Selective Attention | We focus on a very limited aspect of our environment & ignore the rest. |
| Inattentional Blindness | When we fail to see visible objects, because our attention is elsewhere. |
| Change Blindness | When we fail to see a change in our environment, because our attention is elsewhere. |
| sensory adaptation | diminished sensitivity as a consequence of constant stimulation |
| Sensory habituation | Our perception of sensations is partially determined by how focused we are on them |
| cocktail party effect | Ability to concentrate on one voice in a crowd |
| Perception | the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events |
| Energy Senses | Vision (light), hearing (sound waves), and touch (pressure). |
| chemical senses | Our ability to process the environmental stimuli of smell and taste. |
| Cornea | The clear tissue that covers the front of the eye |
| feature detectors | nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement |
| optic nerve | the nerve that carries neural impulses from the eye to the brain |
| occipital lobe | A region of the cerebral cortex that processes visual information |
| color blindness | a variety of disorders marked by inability to distinguish some or all colors |
| afterimages | images that occur when a visual sensation persists for a brief time even after the original stimulus is removed |
| amplitude | The height of a sound wave (volume) |
| Frequency | the number of complete wavelengths that pass a point in a given time. How high-pitched a sound is. |
| cochlea | a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses |
| place theory | in hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated |
| frequency theory | in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch |
| conduction deafness | An inability to hear resulting from damage to structures of the middle ear. |
| sensorineural deafness | deafness that results from damage to the auditory nerve |
| gate control theory | the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "gate" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain. |
| Olfaction | sense of smell |
| vestibular sense | the sense of balance |
| kinesthesis | the system for sensing the position and movement of individual body parts |
| perceptual set | a readiness to perceive a stimulus in a particular way |
| Gestalt Principles | ways for the brain to infer missing parts of a picture when a picture is incomplete |
| monocular cues | depth cues, such as interposition and linear perspective, available to either eye alone |
| binocular cues | depth cues, such as retinal disparity, that depend on the use of two eyes |
| constancy | the tendency to perceive certain objects in the same way regardless of changing angle, distance, or lighting |
| sensory interaction | the principle that one sense may influence another, as when the smell of food influences its taste |
| embodied cognition | the influence of bodily sensations, gestures, and other states on cognitive preferences and judgements |
| five flavors | salt, bitter, sour, sweet, umami |
| Psychophysics | the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them |
| inattentional blindness | failing to see visible objects when our attention is directed elsewhere |
| change blindness | failing to notice changes in the environment |
| selective attention | the focusing of conscious awareness on a particular stimulus |
| context effects | Describes how the context in which a stimulus occurs can contribute to how people perceive that stimulus |
| Accommodation | the process by which the eye's lens changes shape to focus near or far objects on the retina |
| parallel processing | When all feature detectors work together to show us a complete view of the world. |
| phi phenomenon | an illusion of movement created when two or more adjacent lights blink on and off in quick succession |
| stroboscopic effect | images in a series of still pictures presented at a certain speed will appear to be moving |
| Pinna | outer ear |
| middle ear | Eardrum, hammer, anvil, stirrup |
| inner ear | the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs |
| cochlear implant | a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea |
| basilar membrane | a structure in the inner ear that undulates when vibrations from the ossicles reach the cochlear fluid |
