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
Psychophysics
The study of relationships between the physical characteristics of stimuli, such ad 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, of 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 (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 Adaption
Diminished sensitivity as a consequence of constant stimulation
Transduction
Conversion of one form of energy into another. I sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret
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 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 if 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 distant objects focus in front of the retina
Farsightedness
A condition in which far away 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 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
Bipolar Cells
Light energy strikes the rods and cones and produces chemical changes that generate neural signals. These signals activate the neighboring bipolar cells which activate neighboring ganglion cells.
Ganglion Cells
Activated by the bipolar cells. The axons from the network of ganglion cells converge like the strands of a rope to form an optic nerve
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’s cones 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 or most computers and of conscious problem solving
Blindsight
Others who have lost a portion of their brain’s visual cortex to stroke or surgery have experienced blindness in part of their field of vision
Young-Helmholtz Trichromatic (three-color) Theory
The theory that the retina controls three different color receptors – one most sensitive to red, one to green, one to blue – which when simulated 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
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, stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oral window
Cochlea
A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses
Cilia
Hair cells
Inner Ear
The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs
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 if a tone, thus enabling us to sense it’s pitch
Conduction Hearing Loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea
Sensorineural Hearing Loss
(Nerve deafness) - hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves
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 large 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 it’s taste
McGurk Effect
If we see a speaker saying one syllable while hearing another, we may perceive a third syllable that blends both inputs
Olfaction
Experiences of smell
Synesthesia
One sort of sensation (such as hearing sound) produces another (such as seeing color)
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
