Perception study -- ASL vs. Gestures

[Grushkin, Donald A]

Has there ever been a study investigating whether nonsigners with no exposure to ASL or other signed languages can detect the difference between gestures and natural signed languages such as ASL?  I seem to think I did come across something like that once, but cannot rememmber where or who, if it's not a figment of my imagination.  

--Don Grushkin
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