How far will experimentation on human behavior go?

I have just read a Wikipedia article:

http://en.wikipedia.org/wiki/Cognitive_science

I liked this article because it provide information on what procedures are carried out when studying about cognitive science. It shows what is already being experimented.

One sentence from this article that stands out for me is: "A central tenet of cognitive science is that a complete understanding of the mind/brain cannot be attained by studying only a single level." I think this is interesting because I didn't know that several tests with different approaches had to be done just to understand what goes through the brain.

I'm pretty sure this is accurate, because I checked a source, http://plato.stanford.edu/entries/cognitive-science/, that basically sates the same thing. That there are different approaches to studying cognition because so many factors come in to play.

Another sentence that I noticed was: "Psychophysical experiments are an old psychological technique, which has been adopted by cognitive psychology. They typically involve making judgments of some physical property". This stood out for me since my question was based on how behavioral research would advance. This sentence revelas that it is constantly developing and that there are techniques considered "old" which means that they are also constantly finding new ways to gain a better understanding of behavior.
I double-checked this fact through http://psych.hanover.edu/classes/sensation/chapters/Chapter%202.pdf, which makes me feel pretty sure that it is true. This web page reveals the fact that there are different methods, modern and old.

What I learned from this article is that there are advancements and developments made in cognitive research though I am still left with the question: how far will these experiments go? Will it always be just testing humans on memorization and choice or will cognitive psychologists take it to another level? Even if they do, I also learned that research on cognition isn't just one experiment, multiple experiments are performed to gain a better understanding of the human mind.