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U5 S & P Bellanca
Unit 5 Sensation & Perception
Term | Definition |
---|---|
Sensation | taking in information from outside world |
Just noticeable difference | minimum difference between two stimuli required for detection; turning on one light in a dark classroom vs. an already bright classroom |
Absolute threshold | minimum stimulation needed to detect a particular stimulus |
Weber's Law | to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount) |
Signal Detection Theory | Challenges absolute thresholds; Predicts how and when we detect the presence of a faint stimulus(signal) amid background stimulation(noise). |
Habituation | Diminished sensitivity to constant stimulation |
Sensory adaptation | Diminished sensitivity to constant stimulation |
Transduction | Convert physical stimuli into action potentials |
Visual accommodation | eye's lens changes shape to focus near or far objects on the retina |
Rods | Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision |
Cones | Center, Clear details, Color vision |
Acuity | How clearly we see |
Nearsightedness | Can see close up; perfect images from far away occur before image hit retina...making what lands on your retina fuzzy |
Farsightedness | Can see far away; perfect images from close up occur beyond the retina...making what lands on your retina tiny |
Feature detectors | Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement. |
Parallel processing | processing of several aspects of a event simultaneously |
Young-helmholtz trichromatic theory | 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. |
opponent process theory | 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. |
afterimages | cause by stimulation fatigue from your eyes' receptors; starring at a green and white image; then you look to a blank screen and you see red and black; explained by opponent process theory |
cornea | outermost layer of protection that begins the focusing process of incoming light |
pupil | adjustable opening in the center of the eye through which light enters. |
iris | ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening. |
lens | transparent structure behind the pupil that changes shape to help focus images on the retina |
retina | containing the receptor rods and cones plus layers of neurons that begin the processing of visual information. |
fovea | central focal point in the retina, around which the eye's cones cluster. |
blind spot | Where the optic nerve leaves the retina; no receptors here |
optic nerve | nerve that carries neural impulses from the eye to the brain. |
Audition | hearing |
Frequency | How many waves can pass in a given time |
Pitch | Wavelength & Frequency of sound waves; short wavelength, higher frequency = high pitch; long wavelength, lower frequency = low pitch |
Intensity (Loudness) | amplitude of sound wave; great amplitude = loud; small amplitude = soft |
Place theory | |
Frequency theory | |
Conduction hearing loss | physical problem with parts of ear (like eardrum, little bones, etc) resulting in some sort of hearing loss or deficiency |
Sensorineural hearing loss | problem with the cilia or auditory nerve resulting in hearing loss or deficiency |
Gustation | taste |
Taste senses | sweet, salty, sour, bitter, umami (savory, MSG) |
Olfaction | smell |
Olfactory bulbs | where smell is processed in the brain |
Somesthetic sensese | Skin senses (touch), kinesthetic senses, and vestibular senses |
Skin senses (touch) | receptors are pressure, temperature, and pain |
Kinesthetic sense | senes of the location of body parts in relation to the ground and each other |
Vestibular sense | the sensations of movement, balance and body position |
Gate-control theory (of pain) | spinal cord contains "gates" that blocks pain signals or allows them to pass on to the brain. It's opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in large fibers or information coming from the brain. |
Sensory Conflict Theory | An explanation of motion sickness in which the information from the eyes conflicts with the information from the vestibular senses, resulting in dizziness, nausea, and other physical discomfort. |
Perception | sensations experienced at any given moment are interpreted and organized in some meaningful fashion. |
Selective Attention | conscious awareness on a particular stimulus |
Gestalt | whole is greater than the sum of its parts |
Size constancy | Perceiving objects as unchanging even as size of retinal images change |
shape constancy | Perceiving objects as unchanging even as shape of retinal images change |
brightness constancy | Perceiving objects as unchanging even as illumination of retinal images change |
figure-ground | organization of the visual field into objects that stand out from their surroundings |
reversible figures | Visual illusions in which the figure and the ground can be reversed |
proximity | perceive objects that are close to each other as part of the same grouping. |
similarity | perceive things that look similar to each other as being part of the same group. |
closure | tendency to complete figures that are incomplete. |
continuity | perceive things as simply as possible with a continuous pattern rather than with a complex, broken-up pattern. |
Common region (or connectedness) | perception of uniform or linked spots, lines, or areas as a single unit |
Contiguity | perceive two things that happen close together in time as being related. |
Depth perception | ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance. |
Visual Cliff | A laboratory device for testing depth perception in infants and young animals |
Monocular cues | Cues for perceiving depth based on one eye only. |
Linear perspective | tendency for parallel lines to appear to converge on each other. |
relative size | Perception that occurs when objects that a person expects to be of a certain size appear to be small and are, therefore, assumed to be much farther away. |
overlap (interposition) | The assumption that an object that appears to be blocking part of another object is in front of the second object and closer to the viewer. |
aerial perspective | The haziness that surrounds objects that are farther away from the viewer, causing the distance to be perceived as greater. |
texture gradient | tendency for textured surfaces to appear to become smaller and finer as distance from the viewer increases. |
motion parallax | perception of motion of objects in which close objects appear to move more quickly than objects that are farther away. |
binocular cues | Cues for perceiving depth based on both eyes. |
convergence | rotation of the two eyes in their sockets to focus on a single object, resulting in greater convergence for closer objects and lesser convergence I objects are distant. |
binocular disparity (or retinal disparity) | difference in images between the two eyes, which is greater for objects that are close and smaller for distant objects. |
perceptual set (expectancy) | tendency to perceive things a certain way because previous experiences or expectations influence those perceptions. |
Top-down processing | The use of pre-existing knowledge to organize individual features into a unified whole. |
Bottom-up processing | The analysis of the smaller features to build up to a complete perception. |
Parapsychology | The study of ESP, ghosts, and other subjects that do not normally fall into the realm of ordinary psychology. |
Extrasensory perception | The controversial claim that perception can occur apart from sensory input. Said to include telepathy, clairvoyance, and precognition. |