When Can an Object Feel Heavier Than itself? Perceived Heaviness of a Wielded Object Depends on Grasp Position

Perceived heaviness is a function of how an object resists being moved, and such resistance is determined by object mass and the distribution of that mass relative to the wrist. Whereas mass is independent of grasp position on an object, distribution of mass relative to the wrist is not. Therefore, perceived heaviness should vary with grasp position. Blindfolded participants wielded internally weighted cylindrical objects while grasping them at different distances from the centre of mass. They rated how heavy each object felt at each location relative to a standard object. The results show that objects felt heavier as they were grasped farther from the centre of mass, highlighting the role of the touch system in controlling movement.