epiphenomenal

adjective2

1. •
   Being of secondary consequence to a causal chain of processes, but playing no causal role in the process of interest.

   • An organism's consciousness is epiphenomenal to its behavior, and its behavior is determined by unconscious calculations. — 1981
2. •
   Of or pertaining to a mental process that occurs only as an incidental effect of electrical or chemical activity in the brain or nervous system.