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Through the eyes of an animal discusses various aspects of animal vision. It describes how scorpions fluoresce under UV light, possibly for species discrimination or navigation. It then examines the digital camera and how it is analogous to the human eye and retina. Specifically, it notes how the lens focuses light onto sensors which convert light information into electrical and digital signals, similar to how the retina works. Finally, it provides examples of experiments that can test various visual responses in animals, such as the optokinetic response, optomotor response, phototaxis, and how electrode recordings can measure neural responses to light stimuli.

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Through the eyes of an animal: how animals see Ishara Mills-Henry, Ph.D. Science of the Eye Program Saul Nava, Ph.D. Harvard University and Massachusetts College of Art and Design www.scienceoftheeye.org MIT
Animal vision mabt smaller 030912
Animal vision mabt smaller 030912
Animal vision mabt smaller 030912
Animal vision mabt smaller 030912
Animal vision mabt smaller 030912
Emperor Scorpions (Pandinus imperator) Found in the tropical forests and savannas of Africa Docile, although can become territorial and cannibalistic Nocturnal hunts for prey at night Habitat: under rocks, logs, and other forest debris
Scorpion Fluorescence Scorpions fluorescence under UV light. Exoskeleton contains compounds that exhibit flourescence Recent studies suggested its for detection and avoidance of the UV light. Ability to discriminate between species? Mating, navigation, ?)
What do animals see?
What do animals see? New world monkey Pit eyes Great night vision Monocular vision
Digital Camera and the Eye
Observe parts of camera Lenses focuses light onto the sensor IMAGE PROCESSOR Sensor (e.g. CCD) pixels (photosensors) capture light (color and intensity) and convert it to an Convert Convert electrical signal and digital signal Electrical Electrical signal to signal to LENSES Digital Digital Storage Storage SENSOR Image Processing Unit - processes the information, and
Retina The Retina From www.howstuffworks.com
Retina Humans are considered trichromats Blue, Red, and Green Cone Photorecpetors Rod photoreceptors are important for vision in dim light
Three Main Parts: a. Outer Segments b. Cell body c. Synaptic terminal Rods Low light Cones Color vision
Visual Responses Optokinetic Response/Reflex Maintain image on retina stable Innate reflex Optomotor Response/Reflex Locomotive behavior Hypothesized to play a role in control of speed and direction of body movement Innate reflex Escape or Avoidance Response Avert danger Innate reflex Ability to test: Colors, Spatial Frequency, and Motion detection
Observing our eye movements Umbrellas Groups of three One person twists an umbrella while the other tries to focus on the umbrella without moving their eyes. The third person can observe. The umbrella should have a pattern or make stripes on a solid color umbrella with tape
Eye movements (microsaccades) http://www.michaelbach.de/ot/mot_eyeJitter/index.html from Pinna B & Spillmann L (2002) A new illusion of floating motion in depth. Perception 31:15011502. Involuntary eye movements This illusion makes us aware of the small movements our eyes make. Our eyes these movements even if we think we are focusing on an object. This is to prevent the photoreceptors in the retina from desensitizing. If photoreceptors desensitize they will no longer pass the signal to the brain of the object we are seeing. It would reduce the visibility of an object.
Drum lined with black and white stripes Light source illuminates drum
Optokinetic Response Vertebrates exhibit numerous reflex behaviors that are driven by visual stimuli. The OKR response encompasses smooth eye rotations which track moving patterns followed by sharp movements called saccades.
Optomotor Response Zebrafish (http://baierlab.ucsf.edu/omr.html)
Escape or Avoidance Response
Phototaxis Movement towards or away from light
Drosophila Habitat: rotting fruit Phototaxis Eight photoreceptors arranged in a pattern Vision: myopic/poor spatial quality but able to detect movement quickly Smaller lenses captures less light
Mealworms/Darkling Beetles (tenebrio moliter) Over 20,000 species Larval stages are used as a food source fish, reptiles, and birds. Adult darkling beetles active both day and night Habitat: burrows in grain Eat mostly vegetation fresh and decaying Spectral response 520 nm (green) and 334 365 nm (UV) Do they exhibit negative or positive phototaxis? Does the larval stage behavior differ from the adult stage?
Planaria (Schmidtea mediterranea) Flatworms Usually used to study regeneration Habitat: Under rocks in river beds Eye contains pigment and photoreceptor cells
Materials Lights (Color changing light bulb with remote) $8.00 24.00 (Amazon.com) Alternatives: Filters or different color light bulbs Flashlights Light bulb outlets (Home Depot) Mazes (PVC pipe Home Depot) Animals (Available at Carolina or Pet store)
More Interesting Information Flight Simulator for flies? http://www.youtube.com/watch?v=e5uPr_3SsHA&feature=player_embedded May yield info for Robot Vision
What can animals with compound eyes teach us? Better Cameras and motion detection systems?
Measuring Responses Place electrode on eye Light stimulus flashes over the eye
Responses a = Hyperpolarization of photoreceptors b = On- Bipolar cells depolarization d = OFF-Bipolar cells depolarization Ganglion Cell Spike Recordings

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Animal vision mabt smaller 030912

  • 1. Through the eyes of an animal: how animals see Ishara Mills-Henry, Ph.D. Science of the Eye Program Saul Nava, Ph.D. Harvard University and Massachusetts College of Art and Design www.scienceoftheeye.org MIT
  • 7. Emperor Scorpions (Pandinus imperator) Found in the tropical forests and savannas of Africa Docile, although can become territorial and cannibalistic Nocturnal hunts for prey at night Habitat: under rocks, logs, and other forest debris
  • 8. Scorpion Fluorescence Scorpions fluorescence under UV light. Exoskeleton contains compounds that exhibit flourescence Recent studies suggested its for detection and avoidance of the UV light. Ability to discriminate between species? Mating, navigation, ?)
  • 10. What do animals see? New world monkey Pit eyes Great night vision Monocular vision
  • 12. Observe parts of camera Lenses focuses light onto the sensor IMAGE PROCESSOR Sensor (e.g. CCD) pixels (photosensors) capture light (color and intensity) and convert it to an Convert Convert electrical signal and digital signal Electrical Electrical signal to signal to LENSES Digital Digital Storage Storage SENSOR Image Processing Unit - processes the information, and
  • 13. Retina The Retina From www.howstuffworks.com
  • 14. Retina Humans are considered trichromats Blue, Red, and Green Cone Photorecpetors Rod photoreceptors are important for vision in dim light
  • 15. Three Main Parts: a. Outer Segments b. Cell body c. Synaptic terminal Rods Low light Cones Color vision
  • 16. Visual Responses Optokinetic Response/Reflex Maintain image on retina stable Innate reflex Optomotor Response/Reflex Locomotive behavior Hypothesized to play a role in control of speed and direction of body movement Innate reflex Escape or Avoidance Response Avert danger Innate reflex Ability to test: Colors, Spatial Frequency, and Motion detection
  • 17. Observing our eye movements Umbrellas Groups of three One person twists an umbrella while the other tries to focus on the umbrella without moving their eyes. The third person can observe. The umbrella should have a pattern or make stripes on a solid color umbrella with tape
  • 18. Eye movements (microsaccades) http://www.michaelbach.de/ot/mot_eyeJitter/index.html from Pinna B & Spillmann L (2002) A new illusion of floating motion in depth. Perception 31:15011502. Involuntary eye movements This illusion makes us aware of the small movements our eyes make. Our eyes these movements even if we think we are focusing on an object. This is to prevent the photoreceptors in the retina from desensitizing. If photoreceptors desensitize they will no longer pass the signal to the brain of the object we are seeing. It would reduce the visibility of an object.
  • 19. Drum lined with black and white stripes Light source illuminates drum
  • 20. Optokinetic Response Vertebrates exhibit numerous reflex behaviors that are driven by visual stimuli. The OKR response encompasses smooth eye rotations which track moving patterns followed by sharp movements called saccades.
  • 21. Optomotor Response Zebrafish (http://baierlab.ucsf.edu/omr.html)
  • 23. Phototaxis Movement towards or away from light
  • 24. Drosophila Habitat: rotting fruit Phototaxis Eight photoreceptors arranged in a pattern Vision: myopic/poor spatial quality but able to detect movement quickly Smaller lenses captures less light
  • 25. Mealworms/Darkling Beetles (tenebrio moliter) Over 20,000 species Larval stages are used as a food source fish, reptiles, and birds. Adult darkling beetles active both day and night Habitat: burrows in grain Eat mostly vegetation fresh and decaying Spectral response 520 nm (green) and 334 365 nm (UV) Do they exhibit negative or positive phototaxis? Does the larval stage behavior differ from the adult stage?
  • 26. Planaria (Schmidtea mediterranea) Flatworms Usually used to study regeneration Habitat: Under rocks in river beds Eye contains pigment and photoreceptor cells
  • 27. Materials Lights (Color changing light bulb with remote) $8.00 24.00 (Amazon.com) Alternatives: Filters or different color light bulbs Flashlights Light bulb outlets (Home Depot) Mazes (PVC pipe Home Depot) Animals (Available at Carolina or Pet store)
  • 28. More Interesting Information Flight Simulator for flies? http://www.youtube.com/watch?v=e5uPr_3SsHA&feature=player_embedded May yield info for Robot Vision
  • 29. What can animals with compound eyes teach us? Better Cameras and motion detection systems?
  • 30. Measuring Responses Place electrode on eye Light stimulus flashes over the eye
  • 31. Responses a = Hyperpolarization of photoreceptors b = On- Bipolar cells depolarization d = OFF-Bipolar cells depolarization Ganglion Cell Spike Recordings