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BNS 107 Week 11
Vision
Term | Definition |
---|---|
Visible Spectrum | The visible part of the electromagnetic spectrum accounts for only 1/70 of the frequency range. Most of the frequencies are not useful for producing images; for instance, AM, FM, and analog television waves pass right through objects. |
Cornea | transparent front part of the eye that covers the iris, pupil, and anterior chamber. |
Pupil | is not a real structure, but simply a hole in the iris muscle; it looks black because light that enters your eye doesn’t come out. |
Bipolar cells | released from inhibition and they stimulate the ganglion cells |
Amacrine cells | Amacrine cells are interneurons in the retina. Amacrine cells are responsible for 70% of input to retinal ganglion cells. |
Fovea | A 1.5-mm-wide area in the middle of the retina in which cones are most concentrated and visual acuity and color discrimination are greatest. Gives you the most detailed vision |
What are the two retinal photoreceptors? | Rods and cones |
Rods | help to see in dark/low light |
Cones | normal or bright light conditions and color vision |
Rhodopsin | The photopigment in rods that is sensitive to all wavelengths of visible light. |
visual acuity | The ability to distinguish visual details |
retinal disparity | a discrepancy in the location of an object’s image on the two retinas |
lateral geniculate nucleus | The part of the brain that causes what you see in your right field of vision to affect the left side of your brain and vise versa. |
trichromatic theory of color vision | The hypothesis that three color processes account for all the colors we are able to distinguish. |
Color blindness | Also called color vision deficiency; one or more color-sensitive cones is functionally impaired or absent. |
layers of cells that make up the retina | ganglion cells, bipolar cells, receptors (rods/cones) |
Parvocellular ganglion cells (ventral) | located in the fovea, Small, color-opponent circular receptive fields, Discrimination of fine detail and color |
Object agnosia | Impairment of the ability to recognize objects visually |
Prosopagnosia or face agnosia | The inability to visually recognize familiar faces |
Blindsight | The ability of cortically blind individuals to respond to visual stimuli that are outside conscious awareness |
movement agnosia | Impaired ability to perceive movement |
adequate stimulus | The energy form for which a receptor is specialized |
lens | refracts incoming light to focus it on the retina |
retina | The structure at the rear of the eye, which is made up of light-sensitive receptor cells and the neural cells that are connected to them. Images are reverted on the retina. |
ganglion cells | a type of neuron located near the inner surface (the ganglion cell layer) of the retina of the eye. It receives visual information from photoreceptors |
horizontal cells | Horizontal cells play a role in visual processing within the retina. They help improve the clarity and sensitivity of visual information as it is transmitted from photoreceptor cells to the optic nerve. |
optic nerve | nerve that transmits visual information from the retina to the brain. |
Iodopsin | A group of three photopigments found in cones; one form is sensitive to red light, one is sensitive to green light, and one is sensitive to bluish-violet light. |
optic chiasm | The cross that happens in the brain, so that when we see objects on our right, it located in the left side of the brain and vice versa |
visual cortex | Part of each occipital lobe where visual information is processed |
opponent process theory of color vision | A color vision theory that attempts to explain color vision in terms of opposing neural processes. |
retinotopic map | A map of the retina in the visual cortex, which results from adjacent receptors in the retina activating adjacent cells in the visual cortex. |
magnocellular ganglion cells (dorsal) | have large circular receptive fields that are brightness opponents and respond rapidly but only briefly to stimulation. As a result, the magnocellular system is specialized for brightness contrast and for movement. |
Fusiform face area (FFA) | A part of the inferior temporal lobe important in face identification. |
color agnosia | the loss of the ability to perceive colors due to brain damage |
nearsighted | only able to see things that are close to the eye, if they are too far it gets blurry |
farsighted | only able to see things that are far away, when things are too close it is hard to see them |
In addition to visible light, what other forms of energy make up the electromagnetic spectrum? | gamma rays, x-rays, UV rays, visible light, infrared rays |
Where in the eye are the rod and cone photoreceptors located? | In the retina |
What are the two major forms of color blindness? | Dichromacy (missing 1 cone type), monochromacy (missing 2 cone types), and Achromatopsia (missing all cone types which is very rare). |