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Sensation
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment TERM 2
Bottom-Up Processing
DEFINITION 2 Analysis that begins with the sensory receptors and works up to the brain's integration of sensory information TERM 3
Perception
DEFINITION 3 The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events TERM 4
Top-Down Processing
DEFINITION 4 Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations TERM 5
Psycophysics
DEFINITION 5 the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them
Absolute Threshold
The minimim stimulation needed to detect a particular stimulus 50% of the time. TERM 7
Subliminal
DEFINITION 7 Below one's absolut threshold for conscious awareness TERM 8
Priming
DEFINITION 8 The activation, often unconsciously, of certain associations, thus predisposing one's perception, memory or response. TERM 9
Difference Threshold
DEFINITION 9 The minimum differece between two stimuli requred for detection 50% of the time. We experience this as a jnd or just noticeable difference TERM 10
Weber's Law
DEFINITION 10 The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage(rather than a constant amount). In other words: We cannot detect the difference between two stimuli unliss they differ by a certain proportion and that this proportion is constant.
Wavelengths from longest to shortest
Radio Infrared Visable Ultraviolet X-Ray Gamma TERM 17
Complexity
DEFINITION 17 The range of wavelengths in light. Saturation or colorfulness depends on this. TERM 18
Ultraviolet Light
DEFINITION 18 The kind of light that causes sunburns. It has a wavelength somewhat shorter than the violet light at the end of the visible spectrum. TERM 19
Infrared Radiation
DEFINITION 19 Has a wavelength somewhat longer than the red light at the other end of the visable spectrum TERM 20
Vision
DEFINITION 20 Depends on light
Light
Electromagnetic radiation that travels in the form of waves. It is emitted from the sun, stars, fire, and light bulbs. Most other objects just reflect this. TERM 22
Three Features of Light
DEFINITION 22 1.Color-------------Wavelength 2.Brightness--------Amplitude 3.Saturation--------Complexity TERM 23
Wavelenghth
DEFINITION 23 The distance between the peaks of its waves. The color or hue of light depends on its wavelengths. TERM 24
Wave Amplitude
DEFINITION 24 The height of light waves. Brightness depends on light wave this. The brightness of light is related to intensity or the amount of light an object emits or reflects. TERM 25
Hue
DEFINITION 25 The dimension of color that is determined be the wavelength of light; what we know as the color names: blue, green, etc
Accommodation
the process by which the eye's lens changes shape to focus near or far objects on the retina. TERM 32
Retina
DEFINITION 32 light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin processing of the visual information. The image that falls on this part of the eye is always upside down. Light passing through the cornea, pupil, and lens fall onto this region at the back of the eye. TERM 33
Fovea
DEFINITION 33 The center of the retina. It is where the vision is the sharpest; this accounts for the reason that people look directly at an object that they want to inspect. This causes the image to fall on the part of the eye where vision is the clearest. This is also the area where the eyes cones cluster. TERM 34
Nearsightedness
DEFINITION 34 the inability to clearly see distant objects TERM 35
Farsightedness
DEFINITION 35 The inability to clearly see close objects
Cataract
a lens that has become opawue, results in impaired vision TERM 37
Astigmatism
DEFINITION 37 An optical system where rays that propagate in two perpendicular planes have different foci. TERM 38
Glaucoma
DEFINITION 38 is a disease in which the optic nerve is damaged, leading to progressive, irreversible loss of vision. TERM 39
Photoreceptors
DEFINITION 39 Specialized cells that respond to light stimuli. The retina has millions of these called rods and cones. There are many more rods than cones. TERM 40
Rods
DEFINITION 40 Long, narrow cells that are highly sensitive to light and allow vision in very dim conditions. They are retinal receptors that detect black, white, and gray. *These are not present in the fovea which is why vision becomes hazy in dim light *The area just outside the fovea contain many of these cells and these allow for peripheral vision *Because these cells are so sensitive to light in dim conditions peripheral vision is sharper than direct vision
Optic Disk
also called the blind spot because it has no rods or cones. Any image that falls on the blind spost disappears from view TERM 47
How does visual information travel from the
eye to the brain?
DEFINITION 47 *Light reflected from an object hits the retina's rods and cones *Rods and cones send neural signals to the bipolar cells *Bipolar cells send signals to the ganglion cells *Ganglion cells send signals through the optic nerve to the brain *Bipolar and ganglion cells gather and compress information from a large number of rods and cones * The rods and cones that send information to a particular bipolar or ganglion cell make up that cell's receptive field. *Ganglion cell axons from the inner half of each eye cross over to the opposite half of the brain. This means that each half of the brain receives signals from both eyes *Signals from the eyes left sides go to the left side of the brain and signals from the eyes' right sides fo to the right side of the brain. TERM 48
Ganglion Cells
DEFINITION 48 whose axons make up the optic nerve TERM 49
Feature Detectors
DEFINITION 49 is a process by which specialized nerve cells in the brain respond to specific features of a visual stimulus, such as lines, edges, angle, or movement. TERM 50
Parallel Processing
DEFINITION 50 is the ability to carry out multiple operations or tasks simultaneously. The brain's natural mode of information processing for many functions, including vision.
Color Vision
Happens because of two different processes which occur in sequence: 1. The first process occurs in the retina and is explained by the trichromatic theory 2. The second process occurs in the retinal ganglion cells and in cells around the thalamus and visual cortex. The opponent process theory explains this process TERM 52
Trichromatic Theory
DEFINITION 52 or Young-Helmholtz Theory. States 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 *Accounts for colorblindness, and Dichromats TERM 53
Opponent-Process Theory
DEFINITION 53 The theory that opposing retinal processes(Red/Green, Yellow/Blue, and 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. *Explains why most people perceive four primary colors: red, green, blue, and yellow TERM 54
Colorblindness
DEFINITION 54 A hereditary condition that affects a person's ability to distinguish betweeen colors TERM 55
Dichromats
DEFINITION 55 Accounts for most colorblind people, means thay are sensitive to only two of the three wavelengths of light (usually red or green but occasionally blue)
Ground
the background in which the figure stands TERM 62
Figure
DEFINITION 62 What stands out TERM 63
Proximity
DEFINITION 63 How far apart or close together objects are TERM 64
Similarity
DEFINITION 64 Grouping similar objects together TERM 65
Continuity
DEFINITION 65 When people see interrupted lines and patterns they tend to perceive them as being continuous by filling in the gaps.
Simplicity
People tend to perceive forms as simple symmetrical figures rather than irregular ones TERM 67
Depth
Perception
DEFINITION 67 is the visual ability to perceive the world in three dimensions (3D). Binocular and monocular cues help to acheive this. TERM 68
Binocular
Cues
DEFINITION 68 Cues that require both eyes. These types of cues help people to estimate the distance of nearby objects. There are two types: retinal disparity and convergence TERM 69
Retinal Disparity
DEFINITION 69 marks the difference between two images. Because the eyes lie a couple of inches apart, their retinas pick up slightly different images of objects. It increases as the eyes get closer to an object; the brain uses this to estimate the difference between the viewer and the object being viewed. TERM 70
Convergence
DEFINITION 70 Is when the eyes turn inward to look at an object close up. The closer the object, the more the eye muscles tense to turn the eyes nward. Information sent from the eye muscles to the brain helps to determine the distance to the object
Texture Gradient
Smaller objects that are more thickly clustered appear farther away than objects that are spread out in space TERM 77
Linear Perspective
DEFINITION 77 Parallel lines that converge appear far away. Th emore the lines converge, the greater the perceived distance TERM 78
Light and shadow
DEFINITION 78 Patterns of light and shadow make objects appear 3-D even though images of objects on the retina are 2-d. TERM 79
Perceptual Constancy
DEFINITION 79 The ability to recognize that an object remains the same even when it produces different images on the retina. *Example: When someone walks away from you they appear to get smaller and smaller but you do not think of them as shrinking. TERM 80
Shape Constancy
DEFINITION 80 Objects appear to have the same shape even though they make differently shaped retinal images, depending on the viewing angle
Size Constancy
Objects appear to be the same size even though their images get larger or smaller as their distance increases or decreases. This depends to some extent familiarity of the object. TERM 82
Brightness Constancy
DEFINITION 82 People see objects as having the same brightness even when they reflect different amounts of light as lighting conditions change. TERM 83
Color Constancy
DEFINITION 83 Different wavelengths of light are reflected form objects under different lighting conditions. Despited this people see objects as having the same color constancy whether they are indoors or outdoors TERM 84
Illusion
DEFINITION 84 is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation. TERM 85
Muller-Lyer
Illusion
DEFINITION 85 is an optical illusion consisting of a stylized arrow.
Amplitude
Loudness depends on this. It is the height of sound waves. The greater this is the louder the sound perceived. It is measured in decibels. The absolute threshold of human hearing is defined as 0 decibels. Loudness doubles with every 10 decibel increase. TERM 92
Frequency
DEFINITION 92 The number of times per second a sound wave cycles from the highest to lowest point. Determines pitch, which is also deterimined by amplitude. They are directly proportional. TERM 93
Complexity of a Sound wave
DEFINITION 93 Determines Timbre(or the particular quality of a sound) A pure tone has sound waves of only one frequency. Most sound waves are a mixture of different frequencies. TERM 94
Middle
Ear
DEFINITION 94 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 TERM 95
Cochlea
DEFINITION 95 It is the auditory portion of the inner ear. It is a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses
Inner
Ear
The innermost part of the ear containing the cochlea, semicircular canals and vestibular sacs TERM 97
Semicircular Canals
DEFINITION 97 are three half-circular, interconnected tubes located inside each ear. The sixth sense. As the head moves the fluid in the semicircular canals move too, stimulating receptors called hair cells, which then send impulses to the brain. TERM 98
Sensory Information
DEFINITION 98 The principle that one sense may influence another as when the smell of food influences its taste. TERM 99
Kinesthesis
DEFINITION 99 The system for sensing the position and movement of individual body parts.
