Visual Error Augmentation enhances learning in three dimensions

Recent human motor learning and neurorehabilitation experiments have identified the benefits of assisting the learning process by artificially enhancing the errors one might experience. A yet untested question is just how far the nervous system will trust such treatments, especially in transformations with very large sensorimotor discrepancies. Our study asked 10 healthy subjects to perform targeted reaching in a virtual reality environment, where the transformation of the hand position matrix was a complete reversal - rotated 180 degrees about an arbitrary axis (hence 2 of the 3 coordinates are reversed). Our data show that after 500 practice trials, subject who received 2× Error Augmentation (EA) were able to reach their desired target 0.4 seconds more quickly and with a Maximum Perpendicular Trajectory deviation of 0.9 cm less, when compared to the control group. Furthermore, the manner in which subjects practiced was influenced by the error augmentation, resulting in more continuous motions for this group. These data further support that this type of enhancement, as well as possibly other distorted reality methods, may promote more complete adaptation/learning when compared to regular training.