Is a model of the human brain, in which the same interactions between neurons occur as in a real brain, conscious? There currently doesn't seem to be a definitive resolution to that question, and there probably never will be. However, I would argue that the difference between a "useful large scale model of neurons" (where "large scale" means an entire human brain) and "a machine that thinks" (or contains processes which think) is almost nonexistent, unless you subscribe to dualist philosophies.