1. Eye is the window to our soul

2. English physicist Sir Isaac Newton, in an experiment, observed that a ray of sunlight, or white light, was broken up into the brilliant colors of the spectrum when it passed through a glass prism. He then noticed that the ray recombined into white light when it was beamed back through another prism. It occurred to Newton that since light rays are not colored, color must not be an actual physical quality in the world. He concluded that color must exist only in the mind and not in nature. If color does not actually exist in the world around us, then where do colors come from? To answer this question, we will need to understand how our visual sensory system translates different wavelengths of light into neural impulses so that our brain can interpret the information it receives as the sensation of color.

3.  How does the eye work  Phototransduction:  Phototransduction: conversion of light energy turns into neural messages http://www.youtube.com/watch?v=JadaWSDxBYk

5. Visible Spectrum Both Photos: Thomas Eisner

6. 1. Wavelength (hue/color) 2. Intensity (brightness) 3. Saturation (purity)

7.  The distance from the peak of one light wave to the peak of the next. The distance determines the hue (color) of the light we perceive.

9. The amount of energy in a light wave. Determined by the height of the wave. The higher the wave the more intense the light is.

10. Intensity Amount of energy in a wave determined by the amplitude. It is related to perceived brightness.

11. Monochromatic light added to green and red makes them less saturated. Saturated https://www.youtube.com/watch?v=l8_fZPHasdo

13. Two Major Theories

14. Three types of cones:  Red  Blue  Green  These three types of cones can make millions of combinations of colors.  Does not explain afterimages or color blindness well.

15. Opponent-Process Theory- opposing retinal processes enable color vision “ON”“OFF” red green green red blue yellow yellow blue black white white black

16. Hering proposed that we process four primary colors combined in pairs of red-green, blue- yellow, and black-white. Cones Retinal Ganglion Cells

18. The sensory receptors come in pairs.  Red/Green  Yellow/Blue  Black/white  If one color is stimulated, the other is inhibited.

19.  Opponent Processing Theory  Does this make your eyes all weird out??

20. Psychology, 4/e by Saul Kassin ©2004 Prentice Hall  After image: Stare at this picture for around 30 seconds. If you look away from the computer monitor and stare at the wall, do you see an after image on the wall? Opponent Process- Afterimage Effect They are caused by fatigued cells in the retina responding to light.

22. Opponent processing theory: we see in pairs

24.  Rods  concentrated in periphery  approx. 120 million  detect black, white and gray  twilight or low light  Cones  Concentrated near center of eye (fovea)  fine detail and color vision  daylight or well-lit conditions  approx. 6 million Blind Spot- Blind Spot- region with NO rods or cones http://dragon.uml.edu/psych/bspot.html

25. 1. Cornea: Transparent tissue where light enters the eye. (COVERS get it Cornea) 2. Iris: Muscle that expands and contracts to change the size of the opening (pupil) for light. 3. Lens: Focuses the light rays on the retina. 4. Retina: Contains sensory receptors that process visual information and sends it to the brain.

26. Lens: Transparent structure behind the pupil that changes shape to focus images on the retina. Accommodation: The process by which the eye’s lens changes shape to help focus near or far objects on the retina.

30.  Bipolar cells in the first layer translate the information from rods and cones back out to the ganglion cells. Ganglion cells then transfer the information down toward the optic nerve. The point where the optic nerve exits the eye is a blind spot. You cannot see anything because there are no photo-receptors at the point at which those cells exit the retina.  The information is carried down the optic nerve, where it undergoes additional processing. Color information is added at the thalamus. At the end of the optic nerve is the occipital lobe, the structure most responsible for visual processing.

32. http://www.bergen.org Optic nerve: Carries neural impulses from the eye to the brain. Blind Spot: Point where the optic nerve leaves the eye because there are no receptor cells located there. This creates a blind spot. Fovea: Central point in the retina around which the eye’s cones cluster.

34. Use your textbook (p. 207). Close your left eye, and fixate your right eye on the black dot. Move the page towards your eye and away from your eye. At some point the car on the right will disappear due to a blind spot. lab

35.  We need both of our eyes to use these cues.  Retinal Disparity (as an object comes closer to us, the differences in images between our eyes becomes greater.  Convergence (as an object comes closer our eyes have to come together to keep focused on the object).

36. Optic nerves connect to the thalamus in the middle of the brain, and the thalamus connects to the visual cortex.

37. Nerve cells in the visual cortex respond to specific features, such as edges, angles, and movement. Ross Kinnaird/ Allsport/ Getty Images Hubel and Wiesel received a Nobel Prize for their work on Feature Detectors. These specialized nerons in the occipital lobe’s visual cortex receive information from individual ganglion cells in the retina. https://www.youtube.com/watch?v=y_l4kQ5wjiw

38. Processing of several aspects of the stimulus simultaneously is called parallel processing. The brain divides a visual scene into subdivisions such as color, depth, form and movement etc.

39.  The dragon is anything but red.  The dragon rejects the long wavelengths of light that to us are red- so red is reflected of and we see it.  Also, light has no real color.  It is our mind that perceives the color.

40. Genetic disorder in which people are blind to green or red colors. This supports the Trichromatic theory. Ishihara Test

41.  Check out these sites to see what a color blind person sees (normal, red blind, blue blind, monochromatic)  http://www.colblindor.com/coblis-color- blindness-simulator/ http://www.colblindor.com/coblis-color- blindness-simulator/  http://www.webexhibits.org/causesofcolor/2.htm l http://www.webexhibits.org/causesofcolor/2.htm l

42. Color of an object remains the same under different illuminations. However, when context changes the color of an object may look different. R. Beau Lotto at University College, London