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lecture 5A: Vision
Question | Answer |
---|---|
cornea | transparent layer in front of the eye |
Lens | Focuses the image in the back of the eye |
Retina | light sensitive tissue that lines the back of the eye |
Fovea | Point of central focus |
Photoreceptors | cells that line the retina responsible for visual transduction where light (photons) are turned into action potentials |
Pupil | opening in the eye |
Iris | group of muscles that control the size of the pupil |
Rods | sensitive to low levels of light, more importantly contrast |
Cones | discriminate between colors, responsible for detail |
Transduction | Transformation of physical signal into an electrochemical one |
Photopigments | Indirectly causes channels to open when light hits the photopigment |
Lateral inhibition | stimulation of one cell will lead to inhibition in a neighboring cell |
Horizontal cell | responsible for lateral inhibition |
Bipolar/ganglion cells | connect to optic nerve |
Bright physical stimulus | fires a lot |
Gray physical stimulus | fires less |
Convergence | pooling of information from cones and rods onto ganglion cells |
Trichromacy | three "primary" colors |
Dichromat | only see in two colors |
Monochromat | only see in black and white |
Opponent process theory | one type of receptor wll be stimulated vs others |
Visual pathway | process of eye to the brain |
Optic nerve | projection from the retina |
Primary visual cortex (V1) | direct conscious perception and vision |
Optic chiasm | crossing point to optic nerve |
Optic radiations | run from the chiasm to the LGN |
Lateral Geniculate Nucleus | subdivision of the thalamus responsible for processing visual information |
Parvocellular | small cells process info of color in detail (cones) |
Magnocellular | larger cells that are fast and focused on contrast (rods) |