+
Related Flashcards
Related Topics
Cards In This Set
| Front | Back |
|
What is the primary visual pathway?
|
Both eyes process info from both sides of space.Transduction in rods and cones of retina-- Optic nerve-- Optic chiasm where info from left and right sides of space are seperated and what was now on the right is now on the left-- optic tract-- dorsal lateral geniculate nucleus in Thalmus-- optic radiation-- primary visual cortex.
|
|
What is the difference between a nerve and a tract?
|
They are the same, but nerve is used when referring to the peripheral nervous system, and tract is used when referring to the central nervous system.
|
|
What role does the hypothalmus play in the visual pathway?
|
It is a minor stop having to do with Circadian rhythm.
|
|
What role does the Edinger-Westphal nucleus play in the visual pathway?
|
It is a minor stop and deals with pupillary light reflex.
|
|
What role does the Superior Colliculus play in the visual pathway?
|
It is a minor stop and deals with orienting the movements of head and eyes.
|
|
Where does transduction occur in the visual system?
|
In the receptor cells of the retina which are the rods and cones. Rods are more sensitive to low levels of light, cones are more sensitive to greater levels of light.
|
|
What is the retina?
|
The location of the receptor cells for the visual system. The cells here are "inside out". Bipolar cells link receptor cells and ganglion cells. Lateral processing occurs facilitated by horizontal and amacrine cells. Ganglion cells project to the Thalmus.
|
|
What causes the blind spot?
|
It is caused by the optic nerve piercing the retina.
|
|
How does segregation of information work in the right and left eyes.
|
Information from the right side of space is processed on the left side of the brain and vice versa. When info enters the lateral geniculate nucleus this information is still seperate. As projections enter V1 at layer 4 info is still segregated. It is only as ceels project to oether latyers that some start to respond to input from either field.
|
|
How is information processed in the layers of the Lateral Geniculate Nucleus?
|
Magnocellular layers process motion.Parvocellular layers process objects. There are more parvocellular layers.
|
|
What role does the cortex play in the visual system?
|
There are multiple functionally distinct areas in the cortex related to vision. V1 is striated and V2-5 are extrastriate (non-striated) Info from layers 1 and 5 in V1 project to other areas in the cortex related to vision. Most consider V1 to be the terminus of the primary visual pathway.
|
|
What are the aspects of visual perception?
|
Brightness, color, form, depth, objects, motion
|
|
How is brightness perceived and where/when in the processing stream?
|
-It is probably not processed in the retina and is possibly a perception learned from experience. -The mechanism for perceiving brightness is not really understood. Where and how is unknown.
|
|
How is color perceived and where/when in the processing stream?
|
-Color is perceived in the cones of the retina. There are three different types of cones each with different photopigments. These allow us to perceive a range of colors. Rods contain only one photopigment and so do not help with the perception of color. -lesions in V4 impair color perception.
|
|
What is brightness?
|
-Brightess is the most fundamental perceptual quality, the subjective perception of light and dark.-It is related to but independent of luminescence-It is not just the amount of light reflected because it is effected by surrounding sufaces.
|
