2 - Vision Flashcards
What part of the eye gets 2D projections of a 3D world? (Vision Cognitive)
The retina
What are the 4 main parts of the eye? (Vision Cognitive)
- Pupils
- Iris
- Cornea/lens
- Ciliary muscles
What function does pupil the have? (Vision Cognitive)
Light enters the eye
What function does the iris have? (Vision Cognitive)
Adjusts/contracts around the pupil to control the amount of incoming light
What function does the cornea/lens have? (Vision Cognitive)
Focuses light on the retina
What function does the ciliary muscles have? (Vision Cognitive)
Pulls the lens tight to change the refractive index (focuses on different distances)
What are the 2 main parts of the photoreceptor? (Vision Cognitive)
- Rods
- Cones
What is the function of a rod? (Vision Cognitive)
- Contains rhodopsin (light sensitive receptor protein)
- Response to dim lighting
What is the function of a cone? (Vision Cognitive)
- Only work in bright light
- Sensitive to green, red & blue colour light
Starting at the front of the eye, heading towards the back, what features are in the retina? (Vision Cognitive)
- Optic nerve
- Ganglion cells
- Amacrine cells
- Horizontal/bipolar cells
- Cones/rods
What are the 2 groups ganglion cells are broken in to? (Vision Cognitive)
- Large parasol ganglion cells
- Small midget ganglion cells
What are large parasol ganglion cells(LPGC)? (Vision Cognitive)
Take in areas of the retina/input from photoreceptors
What are small midget ganglion cells (SMGC)? (Vision Cognitive)
Take input from a smaller number of photoreceptors
What type of receptor field do LPGC have? (Vision Cognitive)
Large receptor field
What type of receptor field do SMGC have? (Vision Cognitive)
Small receptor field
What processing stream does LPGC connect to? (Vision Cognitive)
Magnocellular
What processing stream does SMGC connect to? (Vision Cognitive)
Parvocellular
What is lateral inhibition? (Vision Cognitive)
When off surround retinal ganglion cells have a normal receptor field that has excitatory connections from the photoreceptors in the centre of its receptor field, and inhibitory receptors in the periphery
What is the lateral geniculate nucleus good at? (Vision Cognitive)
+ Picking out sharp images
+ Filtering information from an input
What is the lateral geniculate nucleus bad at? (Vision Cognitive)
Spotting gradual changes
Where is the lateral geniculate nucleus located? (Vision Cognitive)
Thalamus
What is the relationship between visual field and the lateral geniculate nucleus? (Vision Cognitive)
The lateral geniculate nucleus in the left hemisphere receives information from the right visual field, and vice versa
What are the three layers of the lateral geniculate nucleus and what do they detect? (Vision Cognitive)
1) Magnocellular cells (LPGC) = movement
2) Parvocellular cells (SMGC) = colour and detail
3) Koniocellular cells (in-between layers) = blue/yellow colour detection
What is the primary visual cortex also known as? (Vision Cognitive)
V1 or striate cortex
What does V1 do? (Vision Cognitive)
- Map of the whole visual field
- Not mapped equally
- Reflected in the number of photoreceptors
What is the dorsal pathway? (Vision Cognitive)
Where
What is the ventral pathway? (Vision Cognitive)
What
What are the characteristics of the dorsal pathway? (Vision Cognitive)
- Information streamed regarding location
- Heads for motor system
- Plans motor actions
What are the characteristics of the ventral pathway? (Vision Cognitive)
Specialised information that is out in the world
What does the eye detect? (Vision Cognitive)
- Edge detection
- Contrast detection
What does the thalamus detect? (Vision Cognitive)
Motor perception
What does the cortex detect? (Vision Cognitive)
- Orientation detection
- Face detection
