| sense organs | Organs that receive stimuli.
|
 |
|
|
| sensory receptor cells | Cells in sense organs that translate messages into neural impulses that are sent to the brain.
|
|
|
|
| sensation | The process of receiving, translating, and transmitting messages from the outside world to the brain.
|
|
|
|
| perception | The process of organizing and interpreting information received from the outside world.
|
|
|
|
| stimulus | Any aspect of the outside world that directly influences our behavior or conscious experience.
|
|
|
|
| transduction | The translation of energy from one form to another.
|
|
|
|
| absolute threshold | The smallest magnitude of a stimulus that can be detected half the time.
|
|
|
|
| difference threshold | The smallest difference between two stimuli that can be detected half the time.
|
|
|
|
| sensory adaptation | Weakened magnitude of a sensation resulting from prolonged presentation of the stimulus.
|
|
|
|
| psychophysics | A specialty area of psychology that studies sensory limits, sensory adaptation, and related topics.
|
|
|
|
| Weber's law | A law stating that the amount of change in a stimulus needed to detect a difference is in direct proportion to the intensity of the original stimulus.
|
|
|
|
| electromagnetic radiation | A form of energy including electricity, radio waves, and X rays, of which visible light is a part.
|
|
|
|
| wavelength | The frequency of light waves, which determines the hue we perceive.
|
|
|
|
| cornea | The protective coating on the surface of the eye through which light passes.
|
|
|
|
| iris | The colored part of the eye behind the cornea that regulates the amount of light that enters.
|
|
|
|
| pupil | The opening of the iris.
|
|
|
|
| lens | The transparent portion of the eye that adjusts to focus light on the retina.
|
|
|
|
| ciliary muscle | The muscle in the eye that controls the shape of the lens.
|
|
|
|
| retina | The area at the back of the eye on which images are formed and that contains the rods and cones.
|
|
|
|
| rods | The 125 million cells located outside the center of the retina that transduce light waves into neural impulses, thereby coding information about light and dark.
|
|
|
|
| cones | The 6 million receptor cells located mostly in the center of the retina that transduce light waves into neural impulses, thereby coding information about light, dark, and color.
|
|
|
|
| fovea | The central spot of the retina, which contains the greatest concentration of cones.
|
|
|
|
| visual acuity | Clarity and sharpness of vision.
|
|
|
|
| optic nerve | The nerve that carries neural messages about vision to the brain.
|
|
|
|
| blind spot | The spot where the optic nerve attaches to the retina; it contains no rods or cones.
|
|
|
|
| optic chiasm | The area in the brain where half of the optic nerve fibers from each eye cross to the opposite side of the brain.
|
|
|
|
| dark adaptation | Increased sensitivity of the eye in semidarkness following a reduction in overall illumination.
|
|
|
|
| light adaptation | Regaining sensitivity of the eye to bright light following an increase in overall illumination.
|
|
|
|
| trichromatic theory | The theory of color vision contending that the eye has three different kinds of cones, each of which responds to light of one range of wavelength.
|
|
|
|
| opponent-process theory | The theory of color vision contending that the visual system has two kinds of color processors, which respond to light in either the red-green or yellow-blue ranges of wavelength.
|
|
|
|
| audition | The sense of hearing.
|
|
|
|
| sound waves | Cyclical changes in air pressure that constitute the stimulus for hearing.
|
|
|
|
| frequency of cycles | The rate of vibration of sound waves; determines pitch.
|
|
|
|
| hertz (Hz) | The measurement of the frequency of sound waves in cycles per second.
|
|
|
|
| intensity | The density of vibrating air molecules, which determines the loudness of sound.
|
|
|
|
| pitch | The experience of sound vibrations sensed as high or low.
|
|
|
|
| decibel (db) | Measurement of the intensity of perceived sound.
|
|
|
|
| timbre | The characteristic quality of a sound as determined by the complexity of the sound wave.
|
|
|
|
| pinna | The external part of the ear.
|
|
|
|
| external auditory canal | The tube connecting the pinna to the middle ear.
|
|
|
|
| eardrum | A thin membrane that sound waves cause to vibrate; a structure of the middle ear.
|
|
|
|
| hammer, anvil, stirrup | Three linked bones of the middle ear, which pass sound waves to the inner ear.
|
|
|
|
| oval window | The membrane of the inner ear that vibrates in response to movement of the stirrup, creating waves in the fluid of the cochlea.
|
|
|
|
| cochlea | A spiral structure of the inner ear that is filled with fluid and contains the receptors for hearing.
|
|
|
|
| round window | The membrane that relieves pressure from the vibrating waves in the cochlear fluid.
|
|
|
|
| basilar membrane | One of the membranes that separate the two tubes of the cochlea and on which the organ of Corti rests.
|
|
|
|
| organ of Corti | A sensory receptor in the cochlea that transduces sound waves into coded neural impulses.
|
|
|
|
| bone conduction hearing | Hearing accomplished through sounds transmitted through the bones of the head directly to the cochlear fluid.
|
|
|
|
| vestibular organ | The sensory structures in the inner ear that provide the brain with information about orientation and movement of the head and body.
|
|
|
|
| kinesthetic receptors | Receptors in the muscles, joints, and skin that provide information about movement, posture, and orientation.
|
|
|
|
| saccule, utricle | Fluid-filled sacs of the vestibular organ that inform the brain about the body's orientation.
|
|
|
|
| semicircular canals | Three nearly circular tubes in the vestibular organ that inform the brain about tilts of the head and body.
|
|
|
|
| cupula | A gelatin-like structure containing a tuft of hairlike sensory receptor cells in the semicircular canals.
|
|
|
|
| free nerve endings | Sensory receptor cells in the skin that detect pressure, temperature, and pain.
|
|
|
|
| basket cells | Sensory receptor cells at the base of hairs that detect pressure.
|
|
|
|
| tactile discs | Sensory receptor cells that detect pressure.
|
|
|
|
| specialized end bulbs | Sensory receptor cells that detect pressure.
|
|
|
|
| nocioceptors | Receptors for stimuli that are experienced as painful.
|
|
|
|
| gustation | The sense of taste.
|
|
|
|
| olfaction | The sense of smell.
|
|
|
|
| taste cells | The sensory receptor cells for gustation located in the taste buds.
|
|
|
|
| papillae | Clusters of taste buds on the tongue.
|
|
|
|
| olfactory epithelium | The sheet of receptor cells at the top of the nasal cavity.
|
|
|
|
| stereochemical theory | The theory that different odor receptors can be stimulated only by molecules of a specific size and shape that fit them like a key in a lock.
|
|
|
|
| vomeronasal organ | An organ in the nasal cavity of many animals that contains receptors for pheromones.
|
|
|
|
| pheromones | Chemicals that stimulate receptors in the vomeronasal organ in some animals, influencing some aspects of reproductive behavior.
|
|
|
|
| figure-ground principle | The Gestalt principle of perception that states that part of a visual stimulus will be the center of our attention (figure) and the rest will be the indistinct ground. In many cases, the figure and ground can be reversed in our perception of the same stimulus.
|
|
|
|
| continuity principle | The Gestalt principle of perception that states that lines or patterns that follow a smooth contour will be perceived as part of a single unit.
|
|
|
|
| proximity principle | The Gestalt principle of perception that states that parts of a visual stimulus that are close together will be perceived as belonging together.
|
|
|
|
| similarity principle | The Gestalt principle of perception that states that parts of a visual stimulus that are similar will be perceived as belonging together.
|
|
|
|
| closure principle | The Gestalt principle of perception that states that incomplete figures of familiar objects will tend to be perceived as wholes.
|
|
|
|
| perceptual constancy | The tendency for perceptions of objects to remain relatively unchanged in spite of changes in raw sensations.
|
|
|
|
| monocular cues | Eight visual cues that can be seen with one eye and that allow us to perceive depth.
|
|
|
|
| binocular cues | Two visual cues that require both eyes to allow us to perceive depth.
|
|
|
|
| visual illusion | Visual stimuli in which the cues uesd in visual perception create a false perception.
|