Fig. 7

Subjective feature evaluation for Exp II. Boxplots reflecting the subjectively estimated reliance on the different available feedback sources for task completion in the four feedback conditions (colour-coded with blue for SND, red for VIS, green for VIS + SND, and orange for VIB). Possible feedback sources for closing-velocity estimation were the duration of a stimulus (visual and/or auditory), the speed (visual), frequency (auditory), and intensity (auditory) of the closing hand, and the interaction between the fingers of the prosthesis and the wooden block (visual), while for vibration estimation the frequency and intensity of the tactor could be used. Every boxplot represents the median (circle), interquartile range (box), range (line), and outliers (pluses) of all subjects’ responses. Significant differences within feedback conditions are shown by asterisks in the respective color, black asterisks show differences between single-modality and full feedback tasks