I think you could use any of them. Atropine and scopolamine have been around a lot longer than the others, and of the two, I think atropine is much more toxic. But any one of them should do the job.

If it really hasn't been done before, then a series of studies comparing the cognitive effects of several such agents would be an interesting thesis project. Simple in design, and equally valuable whether the results turned up differences or not.

All these agents do cause amnesia but they are associated with other toxicities.With scopolamine amnesia is observed while other toxicities are minimal