Inducing emotion by unilateral contraction of hand muscles.

Following 4 unilateral contractions of hand muscles, subjects told stories about pictures from the T.A.T. A propositional analysis of the stories showed that the emotional tone of stories told following left hand contractions were more negative than those told after right hand contractions. These results are comparable to those reported following unilateral facial contractions and are consistent with the arousal of the emotional properties of the hemisphere contralateral to the contractions. When the stories were compared to ones told in a control, no contraction condition, it was found that the differences between the left and right contractions were attributable to the effects of either one or the other depending on the control condition responses to the pictures. The results therefore provide evidence for both left and right hemisphere involvement in emotion.