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PSYC 3530 - Exam 3 Questions with Detailed
Verified Answers
answer to #1 Ans: A
Contours Ans: any place in the visual field where light intensity seems
to change abruptly, used for shape; these contours are where there is
contrast because light falls in adjacent areas
lightness contrast Ans: effect in which the intensity of large background
regions can modify the lightness of smaller enclosed areas
lateral inhibition Ans: The pattern of interaction among neurons in the
visual system in which activity in one neuron inhibits adjacent neurons'
responses.
how does lateral inhibition explain lightness contrast effect? Ans: it
enhances edges and borders as a result
Mach bands Ans: an illusion of a band of brightness/darkness at
borders where there are abrupt damages in luminance
spatial frequency Ans: how rapidly stimulus changes across space; the
degree of frequency the grating repeats itself per its visual angle
For a grating stimulus, spatial frequency refers to the frequency with
which the grating repeats itself per degree of visual angle.
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For more natural stimuli, high spatial frequencies are associated with fine
details, and low spatial frequencies are associated withgrosser features
detectors Ans: Channels in the visual system thatare sensitive to
narrow ranges ofspatial frequencies.
Contrast Sensitivity Function Ans: function that represents the visual
system's sensitivity for the range of perceived spatial frequencies.-
Specifically, the function represents the relation between spatial
frequency and threshold levels of contrast.
What spatial frequencies are we most sensitive to? Ans: 2-4 cycles/deg
-lowest contrast to see them
Block Portrait Ans: An image that has been computer processed into a
pattern of small blocks;
- each block is uniform in luminance throughout its area
- and is assigned the same dark-light value as the average value ofthe
original portion of the picture.
Why does block averaging interfere with recognition? Ans: -creates high
frequency noice
-spatial frequency analysis occurs early in vision
-occurs earlier than when we identify what an object is
Why are spatial frequencies important? Ans: -visual displays can be
analyzed by spatial frequency
-one way the visual system encodes complex visual information for
further processing
Perception involves a complex interaction between Ans: bottom-up and
top-down processing
PSYC 3530 - Exam 3 Questions with Detailed
Verified Answers
answer to #1 Ans: A
Contours Ans: any place in the visual field where light intensity seems
to change abruptly, used for shape; these contours are where there is
contrast because light falls in adjacent areas
lightness contrast Ans: effect in which the intensity of large background
regions can modify the lightness of smaller enclosed areas
lateral inhibition Ans: The pattern of interaction among neurons in the
visual system in which activity in one neuron inhibits adjacent neurons'
responses.
how does lateral inhibition explain lightness contrast effect? Ans: it
enhances edges and borders as a result
Mach bands Ans: an illusion of a band of brightness/darkness at
borders where there are abrupt damages in luminance
spatial frequency Ans: how rapidly stimulus changes across space; the
degree of frequency the grating repeats itself per its visual angle
For a grating stimulus, spatial frequency refers to the frequency with
which the grating repeats itself per degree of visual angle.
, Page | 2
For more natural stimuli, high spatial frequencies are associated with fine
details, and low spatial frequencies are associated withgrosser features
detectors Ans: Channels in the visual system thatare sensitive to
narrow ranges ofspatial frequencies.
Contrast Sensitivity Function Ans: function that represents the visual
system's sensitivity for the range of perceived spatial frequencies.-
Specifically, the function represents the relation between spatial
frequency and threshold levels of contrast.
What spatial frequencies are we most sensitive to? Ans: 2-4 cycles/deg
-lowest contrast to see them
Block Portrait Ans: An image that has been computer processed into a
pattern of small blocks;
- each block is uniform in luminance throughout its area
- and is assigned the same dark-light value as the average value ofthe
original portion of the picture.
Why does block averaging interfere with recognition? Ans: -creates high
frequency noice
-spatial frequency analysis occurs early in vision
-occurs earlier than when we identify what an object is
Why are spatial frequencies important? Ans: -visual displays can be
analyzed by spatial frequency
-one way the visual system encodes complex visual information for
further processing
Perception involves a complex interaction between Ans: bottom-up and
top-down processing
