Chapter 6
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If a color is fully saturated, the radiation contains
all wavelengths.
one wavelength.
wavelengths beyond the visible spectrum.
a mixture of wavelengths from a specific band of the spectrum.
Optic nerves join together at the __________, where half of the axons cross to the opposite side of the brain.
calcarine fissure
optic chiasm
optic disk
striate cortex
The first step in visual perception occurs when light
causes a photopigment to split into its two constituents.
enters the sclera.
reaches the brain through the optic chiasm.
causes a change in the receptor potential of the photoreceptor.
Foveal vision is more acute than peripheral vision because
the receptor-to-axon relationships are approximately equal in the fovea.
its photoreceptors respond more quickly to changes in illumination.
its receptive field is near the fixation point.
its ganglion cells fire continuously.
Kuffler found that the receptive field of cat ganglion cells resembles
a mosaic.
a circle surrounded by a ring.
staggered columns.
blobs.
Retinal ganglion cells use a(n) __________ coding system.
trichromatic
relative brightness
opponent-process
black and white
Hubel and Wiesel first suggested that orientation-sensitive neurons in the visual cortex responds best to _______________, but other research indicates the best stimulus is _______________.
lines and edges; spots
low spatial frequencies; high spatial frequencies.
lines and edges; sine-wave gratings
sine-wave gratings; spots
When low frequency information is removed from an image of an object, it becomes
easier to identify.
more difficult to identify.
easier to identify if it is moved closer.
more difficult to identify if it is moved closer.
Neurons that respond to "periodic patterns" are probably used to perceive
surface texture.
depth.
color.
high contrast images.
CO blobs
were discovered in the modules of prestriate cortex.
are organized in ovals within a module.
contain color sensitive neurons.
analyze information from the entire visual scene.
Retinal disparity helps us to recognize
shapes and patterns.
depth.
density.
right and left.
The phenomenon of blindsight includes all of the following except:
the ability to accurately reach for an object held in one's blind field.
visual information that controls behavior without producing a conscious sensation.
connections that the visual association cortex receives from the superior colliculus and dorsal lateral geniculate nucleus.
an early evolutionary development.
The ventral stream of visual association cortex recognizes
the distance of an object from the viewer.
where an object is located.
the identity of an object.
the movement of an object.
Extrastriate cortex
consists of several regions that respond to a particular kind of visual information.
receives information directly from the retina.
performs the initial analysis of visual information.
responds best to familiar stimuli.
Neurons in subarea V4 of extrastriate cortex
have two receptive fields and respond to both.
respond to a variety of wavelengths of light.
are especially sensitive to changes in illumination.
do not respond to orientation.
People with achromatopsia have
difficulty tracking a moving object.
lost some or all of their color vision.
no peripheral vision.
diminished visual acuity.
Inferior temporal cortex
receives information from the magnocellular system.
is found only in primates.
c. performs the analysis of location and movement.
performs the analysis of form and color.
All of the following are true of the TE area except:
It is one of the two major regions of the inferior temporal cortex.
Neurons of the TE have a large receptive field.
Neurons in the TE respond well to simple stimuli such as spots, lines, or sine-wave gratings.
Neurons in the TE appear to participate in the recognition of objects.
Associative visual agnosias are
disconnections between visual perceptions and verbal systems.
failures in high-level perceptions.
genetic abnormalities involving the cones.
inabilities to integrate tactile and visual information.
People with prosopagnosia
have difficulty with visual accommodation.
do not have binocular vision.
do not recognize faces.
are color blind.
Which of the following is not true of the V5 area?
It is part of the extrastriate cortex, also known as MT.
Neurons on the V5 respond to movement.
The V5 is divided into rectangular modules.
Most neurons of the V5 do not show directional sensitivity.
The pulvinar appears
to monitor the position of the body in relation to the setting.
to compensate for the effects of our own movements on movements of images on the retina.
to coordinate eye and hand movements.
to control eye fixation.
Simultanagnosia, one of the symptoms of Balint's syndrome, is the inability to
reach for an object successfully.
scan the contents of a room and perceive object locations.
perceive more than one object in a group.
identify objects by sight alone.
The dorsal stream may be primarily occupied with
guiding actions.
perceiving colors.
identifying objects.
controlling speech.