Simple organisms can be completely pre-wired

C. elegans has:

  • exactly 959 cells including,
  • exactly 302 neurons, whose connections are all known.
  • genome with about a hundred million base pairs.
  • C.elegans worm.

    Yet it is capable of learning.


  • Habituation: capacity to adapt to repeated stimulus and cease to respond to it.

  • Association: discovering and remembering what aspects of the environment predict sources of food or danger.