Orthogonal Organisaton

Question 1

Components of info in V1

Answer 1

Ocolar dominance stripes

Orientation maps

CO Blobs

Question 2

Hypercolumn (Hubel & Wiesel)

Answer 2

Contain all three in one column (Basic processing units) in V1,

Left and right eye parts (ocular dominance) all different orientations represented. w blobs in the middle.

Question 3

Circular RF in retina to oriented RF in cortex

Answer 3

Neurons add up all input on the dendrites: computational power (coincidence detector).

It fires an action potential in an elongated manner (sufficient activation leads to activation of the cortex neuron)

This is the case in a simple cell; the line of the core (+) and the lines of surrounding (-) make it orientation specific.

Question 4

Gabor filter

Answer 4

Sinusoid (wavelines) combined with a Gaussian envelope; description of neurons in V1 for simple cells, you see the wave of -, +, -

Question 5

Development of orientation selective cells

Answer 5

Depends on visual experience during early life. You do have the distribution (even before you’re born) but it needs to be strengthened during development, meaning you need stimuli in that orientation.

Tested in animals, raised with exposure to 1 orientation or many

Statistically, vertical and horizontal representations are overrepresented.