Recurrent signals

Question 1

Recurrent signals in V1

Answer 1

Recurrent signals reflect perceptual organization outcome, aka Gestalt laws. Contextual modulation is present for every possible feature contrast

Question 2

Combining cues

Answer 2

Modulation remains the same if you combine all cues. Segregation from figure background gives you the modulation, the amount of cues doesn’t matter. The only thing modualtion reflects is modulation, regardless of which/how many cues.

Question 3

Perceptual interpretation

Answer 3

In complex scene, where you can interpret an image as eg a floating thing or a frame, V1 neurons reflect the surface segregation. V1 neurons in the floating thing show modulation, but whith the frame, this part would be the background, and you see the neuron doens’t show modulation

Question 4

Kanizsa quares

Answer 4

TMS experiment, disruption of activity in the brain.

Kanizsa requires perceptual organization, and they tested at what point in time they could disrupt this perceptual organization.

Assuming the percept depends on feedforward hierarchical processing, you’d expect that disruption of activity in V1 would disrupt the perception

BUT you find disruption with TMS in later latency LO. So feedback back to V1 is important to interpret the square.