Table 1.

Summary of the experimental protocol

Task	Description
Control Practice	Control the prosthetic hand for two minutes – a combination of close/open the prosthetic hand and abduct/adduct the thumb.
Training and Familiarization	25 trials of grasp-and-lift of the iVE with the breaking feedback and 15 grasp-and-lift trials without the breaking feedback. Each trial lasted for seven seconds.
Adaptation rate test	A total of 40 grasp-and-lift trials. Each trial lasted for five seconds.
Perception threshold test	Grasp-and-lift the iVE in less than four seconds and identify the trial with the added stimulus in a set of two trials, repeat this task until convergence of an adaptive staircase.
Performance test	Transfer the iVE from one side of a barrier to the other 20 times in less than 10 s per transfer.