The latest dour German import finds smart-alecky journalist Bleibtreu (''Run Lola Run'') going undercover in a secretive psych test in which a random group of men spend a fortnight together as prisoners and guards. And wouldn't you know, left to their own devices, those assigned to lock up their fellow countrymen rapidly devolve into a bunch of blood-hungry Nazi types. Agonizingly unentertaining, ''Experiment'' makes you wonder: When did Germany's Holocaust guilt become fodder for a rousing psycho-thriller? EXTRAS Kein.

