Learned Manipulation at Unconstrained Contacts Does Not Transfer across Hands
Figure 2
Compensatory moment and object roll.
The figure shows the time course of compensatory moment (Mcom; solid line) and object roll (dashed line) on pre-transfer trials (Block 1, Trials 1 and 8) and the first transfer trial (Block 2, Trial 1) from 3 representative subjects (S6, switch hand group; S23, switch hand and object rotation group; S28, object rotation group). All subjects started with the right CM. The solid vertical line in each panel denotes object lift onset. Circles denote the subjects’ “ideal” Mcom at object lift onset. The ideal Mcom is the Mcom that subjects should generate at object lift onset to neutralize the external moment generated by the mass added to the object. The left and right vertical axes refer to object roll and Mcom, respectively. Negative and positive values of object roll denote counterclockwise and clockwise roll relative to the vertical, respectively.