@vanschen
What you are implying is that consciousness is a mysterious and intangible thing that is beyond the laws of Physics. You most likely believe that man consists of a soul and a body, and that a soul can exist outside of a body. Whether that is right or wrong remains to be seen.
Perhaps consciousness is just something that emerged from the complex interaction of brain cells, which behave under the laws of Physics. Human cognition would still slow down; that is, if you manage to figure out how to prevent your body from splatting against the spaceship's walls and turning into liquid goo the moment you accelerate to the speed of light:
