Crashing Conclusions

Today in class we were asked: "Do we have free will?"
After pondering for a while about what this really meant, I answered yes. I mean why not? We are to do what we like even if we are ordered to no one is making us do anything. For example today in ethics I was told I couldn’t say something. I replied, “I can say it, whether I should say is different.
Upon sitting down, we were told to listen closely. It was a radio recording discussing the matter. Apparently, these people conducted a “Magic Number” experiment. The volunteers were to memorize number, walk down the hall to another room and say the number. They were intercepted in the hall by a woman offering goodies as a thank you for helping with the experiment. People dealing with 7 digit numbers chose the chocolate cake whereas the fewer-digit volunteers chose the fruit cup. According to these people, since the rational part of the brain was occupied by the number, the emotional part of the brain takes over and chooses the sweet. They proved this point over and over with cases such as choosing types of apples in the supermarket and a student choosing what to do with their life after graduation.
Now, this seems like a very reasonable conclusion. I was reluctant to accept it because I don’t like to be proved wrong. As I finally accepted the theory which then brought forth many more questions.
For example if the brain plays tricks on us, can the rest of your body do that also? Let me paint you a picture:
A six year old child is faced with a plate full of fish sticks and fries. He likes fries because he has tried them before. He doesn’t know so much about the fish. He has no pre-established ideals for what this unusual, crunchy stick-like thing will taste like. After his first mouthful, he tastes sea water, salt and bitterness. He spits it out.
Likes and dislikes aren’t up to you, they’re up to you body. Which leads me to my next question. Are we separate from out body as Epictetus suggests in section 9?"Illness interferes with the body, not with one's faculty of choice."(14 Handbook of Epictetus PDF file) Is it a constant battle? Mind vs. Brain? Emotion vs. Reason? Body vs. Faculty of choice?