The second sentence is the one that sound bad to me.

Artificial intellligence studies have examined the way people think as closely as doctors, psychologists, and philosophers. Most people think that what they do is much like science fiction because of the environement in which the decision processes are completed. As experts in the field agree, however, the environment, whether the supercomputer made by man or the supercomputer called our brains, is becoming less and less relevant to the question of "What is thinking?"

I think the other two sentences can be a little stronger, but it strikes me that they both "hang" on that second one, so fixing it will help me work on the other two.

Thanks in advance!

Maybe it's too late to care, but this might work.

Artificial intelligence seems like science fiction because decisions are being made by computers, not people.

Hope this helps!