Figure 2.

The apparatus used to test proprioceptive accuracy. The apparatus consisted of two LEGO bricks fixated on a horizontal table so as to be parallel with the subject's midsagittal plane. Before each trial, the examiner positioned both fingers on the studs situated at the proximal end of the apparatus. Then, the subject's right index finger was passively moved to one of the studs on the right brick, at variable distance from the start position. Finally, the subject moved the left index finger to place it on a stud of the left brick so as to match the position of the right index finger. The subjects had their eyes closed throughout the experiment and received no feedback on performance.