Note on Animal Perception

From lecture of Science of Behavior

What does it feel to be a bat!?

  • Umwelt: the sensory world of an animal, can be very different from ours.
    • Different precision, range …
    • Use same modality in different ways: Sound Imaging
    • Electro-/Magneto-reception

“More extreme your claim, stronger your evidence!”

**How to define a novel sensory system in animal? **

  • Receptor
  • Anatomical connnections to CNS
  • Stimulus responsive neuron in CNS ()
  • Behavior related to the stimuli
  • Necissity (Lesion study)

Example: Electro Reception

The neurons response for multiple things: Heat, Chemicals, Mechanics! But it’s actually electroreception!

  • Actually, mechanoreceptor and electroreceptor can be activated by mechanical stimuli / optical stimuli both!
    • The sensory modalities that are Maximally sensitive !

Why use Electroreception?:

  • Living Fish generates electric field! (Dead fish don’t)
  • Water is really conductive to electricity!

Behavior Mediated by Eletroreception

  • Find prey under the sand (or in Agar )

Example: Magneto Reception

Mechanism of Large Scale Navigation

  • Example:
    • Homing Pigeon (extreme case): Half a world away, he can find precise location!
  • Map and Campass Hypothesis: Normally needs 2 parts to navigate!
    • Map: Where the target is! Where I am?
    • Compass: What is that direction (relative to me)!
    • Note: Or can we combine the 2 thing?

For a super long distance navigation animal, the campus and map should be available globally and naturally (Geographic knowledge)! Potential options

  • Sun light + circadian time info
    • Note Sun + Time =>Direction, Sun + Direction => Time, without internal clock. The animal will get dis-oriented.
  • Magnetic field / Electric field
  • Sea stream

  • Wind?

  • Check if they use Sun direction?
    • Experiment: Mess with internal clock! (jet lags)
  • Check if they use Magnetic field for direction?
    • Experiment: Mess with magnetic field! (magnet on his body)
    • Result: So Magneto perception is not necessary, but is an alternative of Sun location!
      • In Cloudy days, they lost!
      • In Sunny days, the magnetic pigeons are fine

Magetic field as the loaction information:

  • Magnetic field
    • There are metamers for magnetic field! How they
    • Magnetic field can

Sea Turtle Lifelong Navigation

  • Manipulate magnetic field, see where they swim towards!

Use natural behavior! Just change the environment, see the behavioral change! Simplidied the natural behavior / environment

Manipulate natural

How a de novo sensory system evolve!

Neural plasticity is super-important for this chick and egg problem!

  • With new types of signal comes in
  • The circuit will learn to process it! Associate its inner representation with useful things!
    • The monkey with a new type of cone can see the world in 3 color !!
    • How it process it!

Right Eye and Left eye projection and processing!

Psychophysics (physiology )

Next level more refine question: (Not can they detect) But how physical property translates into perceptual quantities.

  • Intensity ~ Loudness
  • Absolute threshold
  • Relative threshold
  • Scaling:
    • Usually about intensity not other things
  • Tuning

Doing psychophysics in animals requires training!

Habituation and De-habituation

Definition:

Habituation is a good way to test animal can tell the difference

~ related to receptor desensitization

Background Contrast

  • Camouflage & Aposematism

Recognition Learning