There is a common misconception that all animal experimentation has to be painful. Most people have seen pictures of rats being "tortured" or monkeys with sad faces taking part in some kind of experiment, and that type of picture tends to stick.
Of course, there is no denying that many experiments on animals will cause some level of discomfort however, researchers aim at (and are quite good at) minimizing the level of discomfort for animals in experiments. I would even go as far as to say that in most cases dying in a laboratory is probably less painful than dying in nature.
Anyhow, Science magazine recently published an article showing that baboons can learn to distinguish words and non-words. This was an interesting finding (although I must admit that i never surprises me when we learn that monkeys can do things we did not think they could do), however, the reason this study stands out is how "gentle" the study was.
The monkeys were housed in a 30mx25m cage with toys and friends and other types of stimuli that Baboons like. In an adjacent room there was a computer with a touch screen interface. The monkeys could, at their own will visit the computer room. When a monkey entered the room the computer identified the monkey and then the task of distinguishing words and non-words started. If the monkeys got the task right they were rewarded with a treat. When the monkey felt like hanging out with his/her buddies again it would simply leave the room. Sound better than being hunted by a hungry lion on the Savannah if you ask me...
Grainger, J., Dufau, S., Montant, M., Ziegler, J., & Fagot, J. (2012). Orthographic Processing in Baboons (Papio papio) Science, 336 (6078), 245-248 DOI: 10.1126/science.1218152