Vision - Pathways and Brain Flashcards
What is our visual field
Everything we see from both eyes
What is binocular vision
When you can see only whats in front of you (right and left visual fields overlap)
Your left and right visual fields are gone
What is monocular vision
Is the portion of the visual field associated with only one eye
Either left or right peripheries
What crosses at the optic chiasm
ganglion cell axons originating from nasal retina cross the contralateral side
Why do nasal fibers cross
Left brain sees right side and right brain see left side
-left side of each retina has to go to the left hemisphere
Is temporal retina contralateral or ipsilateral
Ipsilateral
What happens when you cut the optic nerve
You will love the monocular vision (peripheries) for one eye being cut (cut left optic nerve will lose left periphery)
What happens when you cut the optic chiasm vertically
Will lose monocular (peripheries) on both sides resulting in binocular vision (aka tunnel vision)
What happens when you cut the optic tract
Will lose the entire contralateral visual field
same as covering one eye with your hand
Why is the Primary visual cortex important (V1)
It is the 1st place in the brain where cells receive signals from both eyes
-has 6 stratified layers
What was the Hubel and Wiesel experiment
- Spots of light stimulate ganglion cells
- Sliding a slit of of light across the visual field caused neurons to discharge
- found that neurons respond best to bar like stimuli with specific orientation
What are the 2 parallel processing streams in the visual cortex
Dorsal Stream
Ventral Stream
What is the dorsal stream
Where and how pathway In the parietal cortex Spatial analysis Motion Visual control of movement
What is the ventral stream
What pathway
Temporal cortex
Object and pattern identification
