Fourier Analysis, Synthesis, and CSF (M2) Flashcards Preview

II. Neurophysiology and Perception > Fourier Analysis, Synthesis, and CSF (M2) > Flashcards

Flashcards in Fourier Analysis, Synthesis, and CSF (M2) Deck (16):
1

What does adding more and more harmonics to a Fourier synthesis get a closer approximation to?

the square wave

2

Describe the visual system as a Fourier analyzer.

RGCs have varying receptive fields that act as more than one type of "spatially-tuned channel" that come together to make up the entire visual system

3

When the stimulus is a low spatial frequency what happens in terms of the center-surround receptive field?

response is minimal because it is excited/inhibited about the same amount (different than blur)

4

From the highest point in the CSF window of visibility, what causes a the loss of contrast sensitivity when the spatial frequency is decreasing?

loss due to lateral inhibition

5

When the stimulus is at a "best" spatial frequency what happens in terms of the center-surround receptive field?

response is strong because it is excited by the center and inhibition is reduced in the surround

6

When the stimulus is a high spatial frequency what happens in terms of the center-surround receptive field?

response is minimal because it is excited/inhibited about the same amount

7

What can express every possible stimulus as a sum of sine waves?

Fourier synthesis

8

What type of spatial frequency filters respond to the fine spatial structure of the world?

high

9

What type of spatial frequencies does the Parasol/Magno pathway relay information?

low spatial frequencies

10

What type of spatial frequency filters encode course luminance variations in the world (large objects and overall shape)?

low

11

What does the CSF data of infants show? 1. Who else has results like these? 2

1. infants use their peripheral retinas for tasks
2. albinos

12

From the highest point in the CSF window of visibility, what causes a the loss of contrast sensitivity when the spatial frequency is increasing?

loss due to blur

13

What type of spatial frequencies does the Midget/Parvo pathway relay information?

all spatial frequencies, including high frequencies

14

What can the sine waves that make up a stimulus be expressed as?

a spectrum in the spatial frequency domain

15

What can analyze every possible stimulus into a series of component sine waves?

Fourier analysis

16

How does a center-surround receptive field act as a filter on the spatial frequency spectrum of the stimulus?

detects information