V1 cell types

Question 1

Simple cell (Gabor filter)

Answer 1

has selective orientation

Destinctive ON and OFF zones (fires in light in ON area, fires when darkens in OFF area)

Responds to flashing bars (if full area is lit, doesn’t fire)

Question 2

Complex cell

Answer 2

Orientation selective

Often also direction selective

Have a wider RF, so fires on any part. Also means there’s no clear ON OFF distinction

The RF of this cell is connected to simple cells, so they feedforward to a complex cell. (hierarchical tuning)

Question 3

Hypercomplex cells

Answer 3

Same as complex but also have end-stopping response, if bar is too long it doesn’t fire.

Question 4

Development of orientation selectivity

Answer 4

LTP (long-term-potential) strengthens the signal thats sent to the brain. this strengthened signal causes development of the selectivity in orientation (you can see red and blue dots alligning).

This shows how all different types of Gabor filters are developed.

Question 5

Spatial freq in cells

Answer 5

simple cells are tunned to orientation and spatial freq.

Because complex cells comparing info of diff spatial freq, the
ON/OFF are not distinctive