Alas, so long as there are strokes, falling objects, cyclists (particularly the helmetless ones), football players, chronic drunkards, Alzheimer's patients, and wars -- i.e. most likely forever -- there will be brain damage. Many of the world's accident victims do not make such convenient test subjects as H.M., but there are more than enough of them for psychologists to get by.

The situation is much improved by the existence of modern brain imaging. It's no longer necessary to cut out a hippocampus to demonstrate that it's required for long-term memory formation.

Then there are other amazing tricks enabled by superior real-time imaging technology. I recall a study in which catheters were used to deliver anesthetics directly to individual hemispheres of people's brains.

Excellent point about the brain damage.

What I was mostly thinking about was studies like the Stanford prison experiment. Studies that require volunteers to be put in unethical situations.

Presumably, the studies will be done -- and the rewards reaped -- by people who don't care so much about ethics.