Flashcards in Module 6.1 Deck (15)
What is the Law of Specific Nerve Energies?
Impulses in one neuron indicate light and impulses in another neuron indicate sound
How is strength of a stimulus encoded?
It depends on the frequency of firing and relative rates of firing.
Trace the path of light into the eye to the retina.
What is the fovea?
an area specialized for acute, detailed vision
How do cells in the fovea connect to other cells? How are these connections different in the periphery of the retina?
Each receptor in the fovea connects to a single bipolar cell and they connect to a single ganglion cell. In the periphery, more cells converge onto bipolar and ganglion cells.
Compare foveal and peripheral vision with regard to location, sensitivity to dim light, and color vision.
Peripheral is the visual area to the side of you and has better sensitivity to dim light than foveal vision. Foveal is the visual area directly in front of you, it's more sensitive to color and detail than the peripheral.
What is a photopigment?
chemical that releases energy when struck by light
What is the relationship of 11-cis-retinal to all-trans-retinal?
Light converts 11-cis-retinal to all-trans-retinal, thus releasing energy that activates second messengers within the cell
What is an opsin?
proteins that modify the photopigments' sensitivity to different wavelengths of light
How did Young and Helmholtz account for color vision? Why is it hard to see small blue dots?
We perceive color through the relative rates of response by 3 kinds of cones, each kind maximally sensitive to a different set of wavelengths.
Long and medium-wavelength cones are a lot more abundant than short-length cones, which are for blue
What kind of theory did Hering propose?
opponent-process theory-we perceive colors in terms of opposites
What evidence supports Hering's theory?
negative color afterimage
What visual abillity does the Retinex Theory explain?
What is the genetic basis for most color blindness deficiency?
their long- and medium-wavelength cones have the same photopigment instead of different ones