Lecture 27

Question 1

simple cells

Answer 1

have clearly defined regions1

Question 2

complex cells

Answer 2

do not have clearly defined regions

Question 3

ocular dominance columns

Answer 3

vertical comuns in area V1

organized in in an inter digitized “left-priming” and right-priming” manner

Question 4

orientation columns

Answer 4

vertical columns in area V1 whose orientation preferences changes in a regular manner until all possible orientations are represented

Question 5

each column is sensitive to input from ______ and respond to ______

Answer 5

same eye

similar orientation

Question 6

Hubel and Wiesel suggested

Answer 6

that one pair of ocular dominance columns including all orientation columns represents one discrete module called hyper column
essentially processes info from a particular location in space

Question 7

intrinsic optical imaging

Answer 7

shine a constant amount of light onto the brain and then record amount of light reflected, improve access by drilling or scraping skull
use subtractive images
red=active

Question 8

optical imaging

Answer 8

each colour represents a group of neurons activated my a specific orientation
organized like a radial pinwheel fashion
thick bands represent ocular dominance bands
dark= left
light= right

Question 9

what are blobs

Answer 9

in V1 process colour

Question 10

how do you see blobs

Answer 10

cytochrome oxidase staining

Question 11

how do we investigate properties of cortical neurons

Answer 11

using adaptation

Question 12

the tilt after effect

Answer 12

adaptation to a pattern at a given orientation

Question 13

adaptation to spatial frequency

Answer 13

We need more contrast in order to see spatial frequencies we could see before

Question 14

Where are the neurons that encode adaptation?

Answer 14

inputs rom the two eyes do not converge until V1, adaptation must happen in cortical neurons

Question 15

High-frequency channels tell us about

Answer 15

detail

Question 16

Low-frequency channels tell us about

Answer 16

broad outlines

Question 17

how do we study vision in infants 2 months-1 year

Answer 17

1. preferential looking

2. Visually evoked potentials

Question 18

preferential looking

Answer 18

babies prefer most complex stimuli they can see

will look more at that stimuli

Question 19

visually evoked potentials

Answer 19

o Presents infants with 2 stimuli

• Measure time spent staring at each stimulus
• Recording with electrodes at back of brain
• Present stimulus on screen and look at how neural response changes
• If can detect might see a VEP greater than baseline
• Results are at a specific level of contrast
• Very fast and can get entire function in a matter of minutes

Question 20

development of CSF in infants

Answer 20

• Sensitivity to low spatial frequencies develops sooner
• bPostnatal changes in the retina limit the development of acuity and contrast sensitivity
• Foveal receptor density increases after birth -> finer cone sampling in later childhood
• Migration of RGCs and inner nuclear layers away from the foveal region (foveal pit) during the first 4 months