8 - VISUAL CORTEX Flashcards
Where is the visual cortex located?
In the cerebral cortex (at the back of your brain).
What is the real of the virtual cortex?
To receive and process visual information.
What receives in the visual cortex receives information from the right and left air?
Neurones
How are neurones grouped together?
In ocular dominance columns
What are these columns called if they receive information from the right eye?
right ocular dominance columns
What are these columns called if they receive information from the left eye?
left ocular dominance columns
How did Hubel and Wiesel study the visual cortex?
1) they stitched one eye of two kittens so they could only see from one eye
2) they kept their eyes stitched for a couple months
3) after that they unstitched the eye and found that the kittens were blind in the eye that was stitched together
4) They also found that the ocular dominance columns for the stitched eye were a lot smaller than normal
5) The ocular dominance columns for the open eye had expanded to take over the other columns that weren’t being stimulated, meaning that the neurones had switched dominance
What does this prove?
It proves that there is something called the critical period where the cat/human has to be exposed to visual stimuli for its visual cortex to develop properly.
How is the visual cortex organised?
By eliminating unnecessary synapses to leave behind only those needed for processing visual information.
Outline the full process of organisation
1) during the critical period of development, synapses that receive visual stimulation and pass nerve impulses into the visual cortex are retained
2) synapses that don’t receive any visual stimulation and don’t pass on any nerve impulses to the visual cortex are removed
3) this means that if the eyes are not stimulated with visual information during this critical period of development, the visual cortex will not develop properly as many of the synapses will be destroyed.
