[ganeshkrishnan]

>The electrical signals in brain are chemical reactions, not conductivity like a metal wire.

Nerve signals are both chemical reactions and electrical impulses like metal wire. Electrical impulses are sent along the fat layer by ions Potassium , Calcium, Sodium etc.

Twitch responses are actually done in spinal cord. The signals are short circuited all along the spine and return back to muscle without touching the brain ever.