Cortical eye structures in visual processing

Question 1

Role of the lateral geniculate nucleus

Answer 1

This is where our optic tract feeds into
- it recieves info from both eyes about the contralateral visual field
-it is organsied into 6 layers;
layers 1 and 2= magoncellular (relay info about form,
movement depth, light and dark contrast)

layers 3-6= parvocellular (relay info about red and green colour and fine detail)

sublayer= loniocellular (relay info about blue colour)

Question 2

Role of the visual cortex/ striate cortex

Answer 2

the cortical region is organised into 6 layers
it receives input from the LGM and is the first cortical region involved in combining visual info with several sources
- it then performs processing of info to give to the extrastriate cortex

Question 3

Role of the Extrastriate cortex

Answer 3

• needed for visual perception
• combines information for perception
• arranged hierachally
• receptive fields become larger and more complex
• infomration moves up the visual association cortices where it is analysed then passed onto hgiher centres for further analysis
• pathways of the extrastriate cortex= dorsal and ventral stream