Download Chapter 3 Vocab

1. Sensation- The stimulation of sensory receptors and the transmission of sensory
information to the central nervous system (the spinal cord or brain).
2. Perception- - Active process by which sensations are organized and interpreted.
- The process by which sensations are organized into an inner representation of the world.
3. Absolute threshold- - Weakest level of stimulus necessary to produce a sensation.
- Detected 50% of the time
(Some people are more sensitive than others.
The same person might have slightly different response at different times)
- The minimal amount of energy that can produce a sensation.
4. Pitch- - The highness and lowness of a sound.
- Is determined by its frequency
5. Subliminal stimulation- - Sensory stimulation below a person's absolute threshold for
conscious perception.
- Its perception is called subliminal perception.
- Visual stimuli can be flashed too briefly to enable us to process them.
- Auditory stimuli can be played at a volume too low to consciously hear and can be
played backward.
6. Difference threshold- - Minimum difference in magnitude of two stimuli required to tell
them apart.
- The minimal difference in intensity required between two sources of energy so that they
will be perceived as being different.
- Detected 50% of the time.
7. Weber’s constant- - Fraction denoting the difference threshold for perceiving differences
in the intensity of energy.
- The fraction of the intensity by which a source of physical energy must be increased or
decreased so that a difference in intensity will be perceived.
8. Just-noticeable difference (JND)- - Minimum difference in stimuli that can be detected.
- The minimal amount by which a source of energy must be increased or decreased so
that a difference in intensity will be perceived.
9. Signal-detection theory- - Factors that determine one's perception of sensory stimuli or
signals.
- Signal intensity or difference between signals.
- Degree to which the signal can be distinguished from background noise.
- The view that the perception of sensory stimuli involves the interaction of physical,
biological, and psychological factors.
10. Sensory adaptation- Sensory adaptation refers to the processes by which we become more
sensitive to stimuli of low magnitude and less sensitive to stimuli that remain the same.
11. Sensitization- - One becomes more sensitive to stimuli of low magnitude
- The process of becoming more sensitive to stimulation
12. Desensitization- - One becomes less sensitive to stimuli of the same intensity.
- The process of becoming less sensitive to stimulation.
13. Visible light- - One small part of a spectrum of electromagnetic energy.
- The part of the electromagnetic spectrum that stimulates the eye and produces visual
sensations.
- Varies in wavelength
14. Hue- The color of light, as determined by its wavelength.
15. Cornea- - Transparent eye cover.
- Transparent tissue forming the outer surface of the eyeball.
16. Iris- - Muscular, colored part of the eye
- Black, Brown, Blue, Green, Yellow
- A muscular membrane whose dilation regulates the amount of light that enters the eye.
17. Pupil- - Opening in the iris.
- Sensitive to light and emotion.
dilate/ constrict
- The black-looking opening in the center of the iris, through which light enters the eye.
18. Lens- - Changes thickness to adjust or accommodate an image.
- A transparent body behind the iris that focuses an image on the retina.
- Images projected onto retina.
19. Retina- - The area of the inner surface of the eye that contains rods and cones.
- The retina consists of cells called photoreceptors.
- The retina contains several layers of cells: rods and cones, bipolar cells and ganglion
cells.
20. Photoreceptors- - Cells that are sensitive to light (photosensitive)
- Cells that respond to light
- Two types of photoreceptors; rods and cones
21. Bipolar cells- Neurons that conduct neural impulses from rods and cones to ganglion
cells.
22. Ganglion cells- - Neurons whose axons form the optic nerve.
- Axons of ganglion cells in the retina converge to form the optic nerve.
23. Optic nerve- - conducts sensory input to brain, where it is relayed to the visual area of the
occipital lobe.
- The nerve that transmits sensory information from the eye to the brain.
24. Rods- - Rod-shaped photoreceptors that are sensitive only to the intensity of light.
- Provide vision in black and white.
- More sensitive to dim light than cones are.
25. Cones- - Cone-shaped photoreceptors that transmit sensations of color.
- Densely packed in a small spot at the center of the retina called the fovea
- Provide color vision
26. Fovea- An area near the center of the retina that is dense with cones and where vision is
consequently most acute.
27. Blind spot- - In contrast to the visual acuity of the fovea is the blind spot, which is
insensitive to visual stimulation.
- The area of the retina where axons from ganglion cells meet to form the optic nerve.
28. Complementary- - Descriptive of colors of the spectrum that when combined produce
white or nearly white light
29. Afterimage- The lingering visual impression made by a stimulus that has been removed.
30. Trichromatic theory- - 3 Types of cones that are selectively sensitive to red, green and
blue light help in color vision.
- The theory that color vision is made possible by three types of cones, some of which
respond to red light, some to green, and some to blue.
31. Opponent–process theory- - 3 types of color receptors that selectively respond to redgreen.
- The theory that color vision is made possible by three types of cones, some of which
respond to red or green light, some to blue or yellow, and some to the intensity of light.
32. Trichromat- - A person with normal color vision.
- Sensitive to red-green, blue-yellow and light-dark.
33. Monochromat- - A person who is sensitive to black (darkness) and white (lightness) only
and hence color-blind.
34. Dichromat- - Have partial color blindness
- A person who is sensitive to black-white and either red-green or blue-yellow and hence
is partially color blind.
35. Closure- The perceptual tendency to fill in gaps in order to perceive disconnected parts as
a whole object
36. Perceptual organization- A) proximity. B) closure. C) continuity.
37. Proximity- The perceptual tendency to group together stimuli that are near each other
38. Similarity- parts of a stimulus field that are similar to each other tend to be perceived as
belonging together as a unit
39. Continuity- parts of a stimulus field that are similar to each other tend to be perceived as
belonging together as a unit
40. Top-down processing- is information processing guided by high-level mental processes,
as when we construct perceptions by filtering information through our experience and
expectations.
41. Bottom-up processing- Involves processing information by starting with the individual
elements of a visual stimulus and gradually building up a final representation and
interpretation
42. Illusions- incomplete form of an image that brain automatically tries to
complete. impossible figure illusion. physically impossible to construct.
43. Perspective- - A monocular cue for depth based on the convergence (coming together) of
parallel lines as they recede into the distance.
44. Texture gradient- - A monocular cue for depth based on the perception that closer objects
appear to have rougher (more detailed) surfaces.
- Closer objects are perceived as having rougher textures.
45. Binocular cues- - Cues that involve both eyes, also help us perceive depth.
46. Retinal disparity- - The difference between the projected images is referred to as retinal
disparity.
- A binocular cue for depth based on the difference in the image cast by an object on the
retinas of the eyes as the object moves closer or farther away.
47. Convergence- - A binocular cue for depth based on the inward movement of the eyes as
they attempt to focus on an object that is drawing nearer.
48. Hertz (Hz)- - A unit expressing the frequency of sound waves. One hertz equals one cycle
per second.
49. Decibel (dB)- - A unit expressing the loudness of a sound
50. Cochlea- - Shaped like a snail shell, contains two longitudinal membranes that divide it
into three fluid-filled chambers
51. Auditory nerve- - The axon bundle that transmits neural impulses from the organ of Corti
to the brain.
52. Frequency theory- - The theory that the pitch of a sound is reflected in the frequency of
the neural impulses that are generated in response to the sound.
- Frequency of the sound waves needs to match with one's neural impulses in order to
perceive lower pitches.
53. Olfactory nerve- - The nerve that transmits information concerning odors from olfactory
receptors to the brain
54. Phantom limb pain- - Perception of pain apparently "in" limbs that have been amputated
(cut off), often because of activation of nerves in the stump of the missing limb.
55. Kinesthesis- - The sense that informs you about the position and motion parts of the
body.
- From the Greek words for "motion" (kinesis) and "perception" (aisthesis)
56. Vestibular sense- - Provides your brain with information as to whether or not you are
physically upright.
- The sense of equilibrium that informs us about our bodies' positions relative to gravity