Building a Visual Scene: Pathways, Maps and Receptive Fields · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

From retinal dots to cortical edges

Science · The Human Body · ages 20-21
Name ______________________   Date ____________
  1. How is a receptive field measured?

    • Electrode recording while flashing stimuli and listening for spikes
    • Weighing the brain after study
    • Asking the animal to draw
  2. What is a visual neuron's receptive field?

    • The blood vessel feeding it
    • The skull bone above it
    • The exact visual pattern that excites the cell best
  3. Each brain half views the opposite visual field.

    Circle one:   True   False

  4. How do simple and complex cortical cells differ?

    • They respond to sound instead
    • They sit in the retina
    • Simple needs exact position; complex accepts the edge anywhere
  5. Which axons cross at the optic chiasm?

    • None of them cross
    • Axons from nasal halves
    • Only the color-carrying axons
  6. The LGN stacks how many layers? Type the count.

    Answer: ______________

  7. A lesion wipes out the left visual pathway past the chiasm. What is lost?

    • Smell on the left side
    • Right field loss
    • Hearing in the left ear
  8. A student hunts V1 fields with tiny spots only. What is missing?

    • Cortex prefers oriented bars
    • Spots damage cortical cells
    • Electrodes cannot record spots
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Answer key

For grown-ups. Fold this page away before handing over the rest.

From retinal dots to cortical edges W1-mt_wOc4YpkdYL-s1

  1. Electrode recording while flashing stimuli and listening for spikes · Recording spikes against changing stimuli maps the best pattern.
  2. The exact visual pattern that excites the cell best · The field is defined by the stimulus that fires the cell hardest.
  3. True · Crossing at the chiasm sends each side the opposite half of the world.
  4. Simple needs exact position; complex accepts the edge anywhere · Both want the right tilt, but only simple cells demand exact placement.
  5. Axons from nasal halves · Inner nasal halves cross while outer halves stay on their side.
  6. 6 · The relay holds six layers, keeping the two eyes separate.
  7. Right field loss · Each side carries the opposite field, so left damage blinds the right side.
  8. Cortex prefers oriented bars · Cortex moved past round fields: tilted edges drive it hardest.
Worksheet · LightMySky