Sentence:  Autosuggestibility , the reaction of the subject in such a way as to conform to his own expectations of the outcome ( i. e. , that the arm-rise is a reaction to the pressure exerted in the voluntary contraction , because of his knowledge that `` to every reaction there is an equal and opposite reaction '' ) also seems inadequate as an explanation for the following reasons : ( 1 ) the subjects ' apparently genuine experience of surprise when their arms rose , and ( 2 ) manifestations of the phenomenon despite anticipations of something else happening ( e. g. , of becoming dizzy and maybe falling , an expectation spontaneously <WSD>volunteered</WSD> by one of the subjects ) . 
Meaning of the word marked with <WSD> tags:  tell voluntarily