Hi. I'm online and happy to answer your question today.
What that test does is look for problems with proprioception and coordination that may be due to being intoxicated. By closing your eyes visual clues as to the relationship between your moving finger and your stationary (hopefully :-) nose are removed. In this situation the major way to correct the trajectory of your finger toward your nose is with the system of receptors and nerves that let you know where in space your finger is and how it is moving.
Sober folks can easily perform this task. Intoxicated folks can't.
Does this make sense to you?
It was a pleasure to assist you with your question. Please let me know if I can do anything else to help you in the future. Positive Feedback and/or Bonus is welcomed and appreciated.
Let me know if there is anything else you would like to discuss pertaining to this issue.
I see that you are offline. I'll switch over to the Q&A system. This system works a lot like 'text messaging' but an email is sent to each of us anytime something is posted to this thread. We can continue to work on your question there..... :)
I like your answer, but need more information I need to study for a human biology test.
Do you know any websites the can read about this topic?