Chapter 5 Flashcards
Perception
The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
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 sensory 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.
Prosopagnosia
Complete sensation but incomplete perception; this is a failure of perception.
Psychodynamics
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
A theory predicting how and when we detect the presence of a faint stimulus (“signal”) amid background stimulation (“noise”). Assumes 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.
Priming
The activation, often unconsciously,mod certain associations, thus predisposing one’s perception, memory, or response.
Difference Threshold
The minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference. (Also called just noticeable difference or jnd.).
Weber’s Law
The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).
Sensory Adaptation
Dismissed sensitivity as a consequence of constant stimulation.
Transduction
Conversion of one form of energy into another. In sensation, the transmission of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.
Wavelength
The distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths very from the short blips of cosmic rays to the long pulses of radio transmission.
Hue
The dimension if 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 changed shape to help focus images on the retina.
Accommodation
The process by which the eye’s lens changes shape to focus near or far objects on the retina.
Retina
The light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers that begin the processing of visual information.
Acuity
The sharpness of vision.
Nearsightedness
A condition in which nearby objects are seen more clearly then distant objects because distant objects focus 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
Retinal receptors 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.
Bipolar Cells
Bipolar cells are a type of nerve cells that combine the impulses from many of the visual receptor cells in the retina and then transmits those impulses to the ganglion cells.
Ganglion Cells
Ganglion Cells are neurons that relay information from the retina to the brain via the optic nerve. There are at least three classes of ganglion cells (midget, parasol, and bistratified), which vary in function and connect to different visual centers in the brain. For example, parasol ganglion cells are responsible for detecting motion, while midget ganglion cells detect visual details.
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.
Fovea
The central focal point in the retina, around which the eye’ scones cluster.
Feature Detectors
Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.
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.
Blindsight
Blindness in part of the field of vision due to destruction in the visual cortex–from a stroke or surgery.
Young-Helmholtz Trichromatic (Three-Color) Theory
The theory that the retina contains three different color receptors–one most sensitive to red, one to green, one to blue–which 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.
Audition
The sense or act of hearing.
Frequency
The number of complete wavelengths that pass a point in a given time (for example, per second).
Pitch
A tone’s experienced highness or lowness; depends on frequency.
Middle Ear
The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window.
Cochlea
A coiled bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.
Cilia
Tiny hairs lining the cochlea.
Inner Ear
The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.
Place Theory
In hearing, the theory they links the pitch we hear with the place where the cochlea’s members in 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 Hearing Loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.
Sensorineural Hearing Loss
Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; also called nerve deafness.
Cochlear Implant
A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.
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 nerve fibers or by information coming from the brain.
Sensory Interaction
The principle that one sense may influence another, as when the smell of food influences taste.
McGurk Effect
A perceptual phenomenon that demonstrates an interaction between hearing and vision in speech perception.
Olfaction
The sense of smell.
Synesthesia
The phenomenon where the senses become joined.
Kinesthesis
The system for sensing the position and movement of individual body parts.
Vestibular Sense
The sense of body movement and position, including the sense of balance.
