Wk 3 SP

Question 1

ratio of ganglion cells to photoreceptors

Answer 1

1:126

Question 2

During single cell recording measuring ganglion response, Before anything is put on the screen, the ganglion cell is already..

Answer 2

active, i.e there is baseline activity

Question 3

A (ganglion cell) cells receptive field is the area

what are the two regions in this area, what do they do

Answer 3

area on the retina which, when stimulated by light, elicits a change in the firing rate of the cell.

Excitatory,
inhibitory response -decrease in firing response

Question 4

two types of centre-surround antagonism (ganglion cells)

Answer 4

ON-centre OFF-surround (central photoreceptor = excitatory of ganglion cell, Surrounding = inhibitory)

OFF-centre ON-surround (opposite)

Question 5

Why have this centre-surround antagonism (ganglion cells) organisation?

Answer 5

Ganglion cells respond to changes in light falling within receptive field
(e.g. if there is an area of dark and area of light indicating a boundary/edge)
Ideal for detecting spots of light & edges
NOT able to detect orientation of bars
No response to changes in overall level of illumination

Question 6

Ganglion cells reduce the amount of information in a stimulus by finding

Answer 6

contours and boundaries

Question 7

A

Answer 7

A