Midterm 2 (Vision 5c)

Question 1

what is colour blindness caused by? (which chromosome, what does it lack?)

Answer 1

gene responsible is contained on the X chromosome. caused by either the lack of a type of cone or a cone that has abnormal properties

Question 2

what is the most common form of colour blindness and what does it result from?

Answer 2

red-green colour blindness. results from the long and medium-wavelength cones having the smae photopigment

Question 3

what does “lateral inhibition” refer to?

Answer 3

the capacity of excited neurons to reduce the activity of their neighbours

Question 4

The Lateral Geniculate Nucleus: part of the ____, specialized for ___ ___, destination for most ____ cell axons

Answer 4

thalamus, visual perception, ganglion,

Question 5

the ____ and _______ constantly feed information back and forth to each other

Answer 5

cortex, thalamus

Question 6

the receptive field refers to the part of the _____ field that either ____ or _____ a cell in the ______ system of the brain

Answer 6

visual, excite, inhibit, visual

Question 7

for a receptor, the receptive field is the point in _____ from which ______ strikes it

Answer 7

space, light

Question 8

list the three types of primate receptive fields (of ganglion cells)

Answer 8

parvocellular neurons, magnocellular neurons and koniocellular neurons

Question 9

Parvocellular Neurons: location, cell bodies and receptive fields, sensitive to ______

Answer 9

mostly located in or near the fovea, have smaller cell bodies and small receptive fields, highly sensitive to detect colour and visual detail

Question 10

Magnocellular Neurons: location, cell bodies and visual fields, sensitive to _____

Answer 10

distributed evenly throughout the retina, larger cell bodies and visual fields, highly sensitive to large overall pattern and moving stimuli

Question 11

Koniocellular Neurons: location, cell bodies, functions, (talk about axons too)

Answer 11

found throughout the retina, have small cell bodies, several functions, their axons terminate in many different places

Question 12

what is astigmatism caused by?

Answer 12

an asymmetric curvature of the eyes

Question 13

what percent of infants have astigmatism?

Answer 13

70 percent

Question 14

what are the two problems that occur with people born with cataracts and have them removed?

Answer 14

difficulty in recognizing objects, and they are unable to tell that components are part of a whole