WEEK 4, The visual system

Question 1

out of the nasal and temporal optic nerves, which cross over the optic chasm?

Answer 1

Nasal, the temporal optic nerves stay on their own outter side.

Question 2

Magnocellular pathway

Answer 2

Low contrast, low spatial frequency, luminance. (light and dark). Goes fast zoom down optic nerve.

Question 3

Parovcellular pathway

Answer 3

high contrast, high spatial freqnecy, colour (detail)

Question 4

Retinotopic map.

Answer 4

that when we see an iage our whatever, our primary visual cortex lights up in correspondance of that image (like foreground, backgronud etc) over representation of the central visual field.

Question 5

what are the two types of receptive fields in neurons?

Answer 5

On centre/off surrond (if info hits central visual field, it fires.)
Off centre/ on surrond (opposite)

Question 6

briefly explain what a receptive field is

Answer 6

Receptive field, region in the sensory periphery within which stimuli can influence the electrical activity of sensory cells. The receptive field encompasses the sensory receptors that feed into sensory neurons and thus includes specific receptors on a neuron as well as collectives of receptors that are capable of activating a neuron via synaptic connections

Question 7

phototopic vision

Answer 7

Light vision, cones, high acuity, low convergence, low sensitivity with few receptors.

Question 8

Scotopic vision

Answer 8

Dark/dim vision. rods, low acuity, high convergence, periphery.

Question 9

dorsal stream

Answer 9

action (where). Sits at parietal occipital area.

Question 10

Ventral stream

Answer 10

perception (what). Sits around occopital temporal area.

Question 11

Akinetopsia

Answer 11

Damage to V5 in both hemisphere, see the world in snapshots, like watching a shit skype connection.

Question 12

Archomatopsia

Answer 12

Stroke in both hemispheres, patient can see fine, but everything they see is a shade of grey. no colours.