Lecture 4: Spatial Vision

Question 1

What is the tilt after effect

Answer 1

When looking at bars (like those in the sinewave image) for a 60s time period, then look away and look back, the bars may no longer appear vertical.

Question 2

Describe the structure of the neurons in the visual cortex

Answer 2

The neurons are organised into 6 different layers, each receiving input from different areas in the LGN.

Question 3

Retinotopy:

Answer 3

Neighboring relationships in retina are retained in the cortical map.

Question 4

Describe the organisation of neurones in the V1

Answer 4

Neurons are stacked on each other that respond to the same orientation (orientation columns) and also have ocular dominance bands which are bands of neurons that respond to one eye (binocular).

Question 5

How can we measure the optimal response for receptive fields?

Answer 5

Sineward/sinusoidal gratings

Question 6

What can you measure using Sineward and Sinusoidal Gratings?

Answer 6

Orientation, spatial frequency, contrast and phase

Question 7

what does the size of the retinal image depend on and how do you quantify it?

Answer 7

Depends on how far away the object is and can be quantified by the measure of the visual angle.

Question 8

What is a Fourier analysis?

Answer 8

Mathematical analysis decomposes images into sinewaves to compare components of the images.

Question 9

‘Adaption’ as a method

Answer 9

Stare at the same stimuli for a long period of time to see how the visual system reacts

Question 10

‘Adaptation’ as process

Answer 10

As a consequence of long exposure, neurons that are tuned to the stimulus property decrease sensitivity.