A SF short story about a man locked in a house?

the man seems tobe in trouble with his memory as he keep stearing at a plane or spaceship model. The house has no windows and there are other people living in it but he seems disturbed about the way everything is provided for them untill a day he sees sommebody behing a lotch where they normally get provisions from. next day he manages to escape the house and is captured. We them learn that he and the rest of the people in the house are a group of ailen captured during their metamorphosy into humam when they lose their memory and are kept in the house for study. anybody know the author, title or anything?