Couldn't the protocol be set up like a psych experiment in which you misdirect the subject (making the sleeping mask incidental from the subject's perspective)?
I'm assuming your objection is that the research biased the results by informing the subjects that they are testing the effect of sleeping masks on "episodic learning and alertness"?
I'm assuming your objection is that the research biased the results by informing the subjects that they are testing the effect of sleeping masks on "episodic learning and alertness"?