Vision Lecture Notes

Question 1

Light

Answer 1

Light enters the eyeball through the pupil and is received on the retina, where it is transduced into neural signals. The signals are transmitted by the optic nerve to the brain where they are processed in the primary visual cortex, located in the occipital lobe producing our experience of vision

Question 2

Cornea

Answer 2

Clear front part of the eye covering the iris and the people. It does about two thirds of the focusing/refracting of light

Question 3

Vision

Answer 3

Our eyes receive lights energy and transforming it into neural messages that the brain processes into what we consciously experience as sight

Question 4

Pupil

Answer 4

The hole in the center of the iris which allows light to enter the eyeball. It increases or decreases in size to adjust to the amount of light that enters the eye

Question 5

Lens

Answer 5

Changes shape to help focus light on the retina. It does about one third of the focusing/Refracting

Question 6

Retina

Answer 6

Light-sensitive inner surface of the eye. Located in the back of the eyeball. Contains the rods and cones and layers of neurons that process light into neural messages.

Question 7

Photo activation

Answer 7

a photochemical reaction that occurs when light hits photoreceptors, producing a neural signal

Question 8

Rods

Answer 8

Photoreceptors that detect black, white and get. Concentrated toward the outer edge of the retinal necessary for peripheral and low light vision. Very sensitive to light. A single photon fan activate a rod.

Question 9

Cones

Answer 9

Photoreceptors that are concentrated toward the center of the retina. For color vision and fine details. They work well when there is plenty of light. They are less sensitive to light than rods. We have more rods than cones.

Question 10

Optic nerve

Answer 10

The nerve that carries the neural includes from the retina to the brain

Question 11

Blind spot

Answer 11

The point where the optic nerve leaves the eye. This part of the retina is blind because it had no receptor cells

Question 12

Fovea centralis

Answer 12

Located in the center of the retin. Responsible for sharp central vision. About half of the divers in the optic nerve carry messages from the fovea. Mostly cones.

Question 13

Feature detectors

Answer 13

Neurons in the visual cortex that receive visual information and responds to lines, edges and angles

Question 14

Contrast

Answer 14

The relative difference in the amount of light and type of light coming from two nearby locations. The visual system uses contrast to perceive different objects

Question 15

Hue

Answer 15

The frequency of a lightweight determines the hue (color)

Question 16

Frequency

Answer 16

The frequency is determined by the wavelength (the distance from one peak to another on a lightwave). Short wavelengths equal high frequencies and long wavelength equal low frequencies

Question 17

Trichromacy Theory (Young Helmholtz)

Answer 17

A theory that proposes that all of our color perception is based on the combination of three different color signals. Shorts preferring (blue S pounds), middle preferring (green, M cones) and long preferring (red L Cones).

Question 18

Opponent process theory (Ewald Hering)

Answer 18

Stated that color is coded by three opponent channels (red/green, blue/yellow, and black/white.) Colors are perceived as differences between two Hues not just a simple combination of them. when one element is stronger than the other the stronger color is perceived in the weaker one is suppressed

Question 19

Intensity

Answer 19

The amount of energy in the lightwave. This is determined by a light waves amplitude, which is the heights of a wave. The higher the intensity, the brighter the color.

Question 20

Colorblindness

Answer 20

The gene that produces photo pigments are located on the X chromosome. If these jeans are missing or defective, it can result in color blindness.