What is "muscle reading"

Muscle reading \Mus"cle read`ing\ The art of making discriminations between objects of choice, of discovering the whereabouts of hidden objects, etc., by inference from the involuntary movements of one whose hand the reader holds or with whom he is otherwise in muscular contact.

Muscle reading, also known as " Hellstromism", "Cumberlandism" or "contact mind reading", is a technique used by mentalists to determine the thoughts or knowledge of a subject, the effect of which tends to be perceived as a form of mind reading. The performer can determine many things about the mental state of a subject by observing subtle, involuntary responses to speech or any other stimuli. It is closely related to the ideomotor effect, whereby subtle movements made without conscious awareness reflect a physical movement, action or direction which the subject is thinking about. The term "muscle reading" was coined in the 1870s by American neurologist George M. Beard to describe the actions of mentalist J. Randall Brown, an early proponent of the art.