Are We Real When We Fake? Attunement to Object Weight in Natural and Pantomimed Grasping Movements

Front Hum Neurosci. 2016 Sep 22:10:471. doi: 10.3389/fnhum.2016.00471. eCollection 2016.

Abstract

Behavioral and neuropsychological studies suggest that real actions and pantomimed actions tap, at least in part, different neural systems. Inspired by studies showing weight-attunement in real grasps, here we asked whether (and to what extent) kinematics of pantomimed reach-to-grasp movement can reveal the weight of the pretended target. To address this question, we instructed participants (n = 15) either to grasp or pretend to grasp toward two differently weighted objects, i.e., a light object and heavy object. Using linear discriminant analysis, we then proceeded to classify the weight of the target - either real or pretended - on the basis of the recorded movement patterns. Classification analysis revealed that pantomimed reach-to-grasp movements retained information about object weight, although to a lesser extent than real grasp movements. These results are discussed in relation to the mechanisms underlying the control of real and pantomimed grasping movements.

Keywords: kinematics; linear discriminant analysis; object weight; pantomime; reach-to-grasp.