sample_exam_2002_sol

sample_exam_2002_sol - Part 1 (multiple choice, circle the...

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Part 1 (multiple choice, circle the correct choice for each question) Part 2 (1.1 points) : An experiment is performed where you apply heat to your index finger for a couple of minutes. Immediately after this you place the same hand in lukewarm water. Given that there are somatosensory receptors for temperature, and that cold is the absence of heat, what would you perceive on your hand when it is put in the lukewarm water? Be sure to describe what the index finger would feel like relative to the rest of your hand The index finger would feel colder than the rest of the hand (which would be lukewarm) This is an example of an adaptation illusion (like the flag and spiral illusion) where we over stimulate cells on the index finger which code heat. Then when we put the hand in lukewarm the adapted/habituated cells respond less than the rest of the hand. Since heat receptors respond less. A lack of heat or cold is perceived at those points, that is the index finger.
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Part 3 3.1 (0.5 points) Label the names for A-E on the picture below 3.2 (0.6 points). Indicate the most correct choice (A-E) for the descriptions of various parts of the eye below 3.2b) The part of the eye that is adapted for acute vision with a dense area of photoreceptors. 3.3 (1.3 points, multiple choice 0.2 points, explain 1.1 point) If we increased the sodium concentration inside of some photoreceptors, the person would perceive those points in space as (1) lighter (2) darker (3) the same Explain 3.3 If we increased the sodium inside, this would (1) tend to make the membrane potential (and/or receptor potential) more negative (2) because Ena decreases. (3) A photoreceptor becomes more negative when light is increased , that is a photoreceptor encodes darkness) . (4) Since the photoreceptor became more negative these points would be perceived as lighter or brighter (since photoreceptor encodes darkness, and it hyperpolarizes Æ brighter) . (purple shows an alternate explanation.) A. ___Retina__ B. ____Pupil__ C. _Fovea______ D. ___Optic nerve___ E. ___LENS________ D C
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Part 4. (total 3.8 points) The receptive field (RF) of two visual neurons (cell 1 and 2) and their connections to a post-synaptic neuron (cell 3) are shown below. The intersect of the dashed lines on the drawing of each RF indicates straight ahead, so the RFs are all centered on the same point straight in front of the animal. The inhibition and excitation are of equal and opposite strength .. 4.1. (1.0 points) Draw the receptive field of cell 3 on the blank graph above. 4.2 (0.8 points) For all 3 questions (cells) choose all the correct choices from a-g. Zero, one or more Cell 1 is? B Cell 2 is? B Cell 3 is? B (a) a retinal ganglion cell (b) a visual cortical cell (c) an LGN Cell (d) a bipolar cell (e) a nucleus laminaris cell (f) a horizontal cell
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This note was uploaded on 12/06/2009 for the course NPB 100 taught by Professor Chapman during the Fall '08 term at UC Davis.

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sample_exam_2002_sol - Part 1 (multiple choice, circle the...

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