Sense and Perception

Question 1

What does our sense of sight allow us to do?

Answer 1

Allow us percieve the world around us

Question 2

How much of the human brain is involved in vision and other things?

Answer 2

About 1/4 of the human rbain is involved in visual processing

Question 3

How does vision being?

Answer 3

Wiht light passing through the cornea which does 3/4 of the focussing and then the lens which adjusts the focus. Both combine to produce a clear ima

Question 4

What do the cornea and lens combine to produce?

Answer 4

A clear image of the visual world o the sheet of photoreceptors in the retina.

Question 5

As in a camer, the image on the retina is

Answer 5

reversed. Objects to the right of center project images to the left part of the retina and vce verse. Objects above the center project to the lower pat and vice versa.

Question 6

The size of the pupil which regulates how much ligth enters the eye is controlled by the r

Answer 6

Iris.

Question 7

How many photoreceptors are in each eye?

Answer 7

About 125 million are neurons specialized to turn light into electrical signals

Question 8

What two forms do photoreceptors occur in?

Answer 8

Cones and rods

Question 9

What are rods ensitive to

Answer 9

dim light and do not convy color

Question 10

Cones

Answer 10

work in brigt light and are responsibe for acute detail, black and white vision and color vision

Question 11

The cones occur in three,….

Answer 11

Differnt range of colors. Because thier sensitivities overlap, cones work in combination to convey information about all visible colors. Red, Green and Blue

Question 12

What is binocular vision?

Answer 12

Well developed vision using two eyes, called binocular vision. Visual signals pass form each eye along the million or so fibers of the optic nerve to the optic chism hwhere some nerve fobers cross over so both sides of the brian revcieve signals

Question 13

Basically, how are your brain and eyes wired?

Answer 13

Your right brain sees your left and your left brain sees your right

Question 14

Scientists know much about he way cells encode visual information in th retina–whch is also called:

Question 15

The retinal contians how many stages of neurons

Answer 15

3

Question 16

The first, thelayer of rods and cones sends it signals to the

Answer 16

middle layer which relays ignals to the third layer which conssits of the ganglion cells whose axons form the optic nerve

Question 17

Each cell in the middle and third layer recieves input from

Answer 17

many cells in the previous layer, but the number of in puts varies widely across the retina.

Question 18

Near the center of the gaze, where visual acuity is highest, each cell i nthe third layer recieves inuts from

Answer 18

the middle layer

Question 19

Near the margins of the retina, each cell inthe third layer receives signals form a cluster of many

Answer 19

rods and cones

Question 20

An area of visual space, providing inputto a visual neuron is calle..

Answer 20

a receptive field

Question 21

About 55 years ago, what did scientists discover?

Answer 21

That the receptive field of a vision cell is activated when light hits a tiny region in its receptive field center and its inhibted when light hits the part of the receptive field around the center

Question 22

Visual information form the retina is relayed through the lateral geniculate nucleus of the thalamus to the primary visual cortex, a thin sheet of tissue

Question 23

The primary visula cortex is densely packed iwht cells in many layers, n its middle layer which recieves messages form

Answer 23

the lateral geniculate nucleus, scientits hav ound resonses similart to those observed in the retina and in lateral geniculate cells

Question 24

Cells above and below this layer respond differently hOw?

Answer 24

They prefer stimuli in the shape of bars, or edges and those at a praticular angle

Question 25

Although the process is not completely understood,recent finding suggest that visual signals are fed into at least

Answer 25

three seperate processing systems

Question 26

One system is about

Answer 26

shape

Question 27

What is the second system

Answer 27

color

Question 28

What is the third system about?

Answer 28

It is about movement, location and spatial organization

Question 29

Thes findings of seperate processing systems come form what studies

Answer 29

anatomical and physiological

Question 30

What is Gestalt psychology says ( Its about movemen t and depth perception)

Answer 30

IT says that perception requirs various elements to be organized so that relatedones are grouped together . This stems from the brain’s ability to group the parts of an image together and also separate images from on another

Question 31

How do all of these system combine to produce the vivid images of solid objects?

Answer 31

That htis involves extracting biologicaly relevant information at each state and associating firing patterns of neuronal populations