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ACTIVE SENSING

ACTIVE SENSING. Lecture 8 : Electric fish control loops. ELECTRIC FISH. Course assistants. Erez Simony: erez.simony@weizmann.ac.il Avi Saig: avi.saig@weizmann.ac.il. Exercises Course list. Energy-emitting active sensing. Geometry.

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ACTIVE SENSING

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  1. ACTIVE SENSING Lecture 8 : Electric fish control loops ELECTRIC FISH

  2. Course assistants • Erez Simony: erez.simony@weizmann.ac.il • Avi Saig: avi.saig@weizmann.ac.il Exercises Course list

  3. Energy-emitting active sensing Geometry M. E. Nelson ֶ M. A. MacIver J Comp Physiol A (2006) 192: 573–586

  4. Energy-emitting active sensing Frequency and duration ranges M. E. Nelson ֶ M. A. MacIver J Comp Physiol A (2006) 192: 573–586

  5. Energy-emitting active sensing detection range Bat (detecting musquitoes) Dolphin (typical prey) Rat (contact range) Electric fish (daphnia) M. E. Nelson ֶ M. A. MacIver J Comp Physiol A (2006) 192: 573–586

  6. The prey: Daphnia signal characteristics • Mechanosensory stimuli • Low-frequency bioelectric fields • Perturbations to the fish’s high-frequency electric field Daphnia 1 mm

  7. Principle of active electrolocation M. E. Nelson

  8. Prey capture behavior

  9. Prey capture kinematics Longitudinal velocity acceleration Distance to closest point on body surface

  10. emitted-energy active sensing Complications with • conspicuousness • Detection of energy by prey and predators • confusion with peers

  11. emitted-energy active sensing Adaptations specific to • conspicuousness • Detection of energy by prey and predators • confusion with peers • technology war • ciphering • jamming avoidance

  12. Technology war make the probe less conspicuous to the prey/predator. Example: echolocating killer whales A  dolphins echolocating killer whales B  fish Dolphins can detect the ecolocating signals Fish cannot echolocating killer whales A use irregular short clicks echolocating killer whales B use continuous emission

  13. Technology war make the probe less conspicuous to the prey/predator. Example 2: The prevalence of passive vision systems make it difficult for bioluminescence-based active photoreception to be a viable strategy in most ecological niches. Solution 1: Flaslight fish open and close a “lid” to expose their light organ briefly Solution 2: In deep sea, vision is usually based on the blue-green portion of the spectrum. deep-sea dragonfish have two bioluminescent organs, one of which produces a near infrared wavelength of light that only they can see.

  14. Ciphering keep a private signal that allows decoding the echo Example: CF-FM echolocating bats 1st harmonic is weak and does not reach the peers 2nd harmonic is loud and also echoed well pairing of 2nd harmonic (source) & delayed 2ndharmonic (echo) would include peer calls These bats have evolved cells that respond to 1st harmonic & delayed 2nd harmonic other ciphering tricks?

  15. Jamming avoidance

  16. Jamming avoidance Masashi Kawasaki Current Opinion in Neurobiology 1997, 7:473-479

  17. Jamming avoidance WALTER METZNER, The Journal of Experimental Biology 202, 1365–1375 (1999)

  18. emitted-energy active sensing Adaptations specific to • conspicuousness • Detection of energy by prey and predators • confusion with peers • technology war • ciphering • jamming avoidance

  19. Prey capture behavior

  20. F d P What is the control loop? how to design a prey-capture loop P d F

  21. F d P What is the control loop? how to design a prey-capture loop P d F

  22. What is the control loop? how to design a prey-capture loop ? P d F K1 F d P

  23. Prey capture kinematics Longitudinal velocity acceleration Distance to closest point on body surface

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