Visual error augmentation enhances learning in three dimensions

Abstract

Because recent preliminary evidence points to the use of Error augmentation (EA) for motor learning enhancements, we visually enhanced deviations from a straight line path while subjects practiced a sensorimotor reversal task, similar to laparoscopic surgery. Our study asked 10 healthy subjects in two groups to perform targeted reaching in a simulated 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 showed that after 500 practice trials, error-augmented-trained subjects reached the desired targets more quickly and with lower error (differences of 0.4 seconds and 0.5 cm Maximum Perpendicular Trajectory deviation) 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 and smaller errors. Even with the extreme sensory discordance of a reversal, these data further support that distorted reality can promote more complete adaptation/learning when compared to regular training. Lastly, upon removing the flip all subjects quickly returned to baseline rapidly within 6 trials.

Visual error amplification showed no benefit for non-naïve subjects in trunk-arm rowing

“…is the reference oar angular position and q act (t) is the actual subject oar angular position at time t. To augment the perceived instantaneous tracking error, we need to either distort the displayed reference oar angular position, the rendered subject oar angular position, or both. We decided to distort the rendered subject oar position, which seems to be the most common approach taken for visual error amplification (Celik et al, 2009;Patton et al, 2013;Sharp et al, 2011;. The subject oar was rendered at an angular position q EA (t):…”

“…A typical implementation of error augmentation is augmenting spatial errors only. In reaching movements, the distance from the end-effector to a straight line between start and target position has been used for error augmentation (Celik, Powell, & Malley, 2009;Patton, Wei, Bajaj, & Scheidt, 2013;Sharp, Huang, & Patton, 2011;. Spatial error augmentation can be applied to arbitrary trajectory tracking movements, e.g.…”

“…The most common visual error augmentation is a linear amplification of the error ϵ amp = p EA ⋅ ϵ with a constant gain p EA , e.g. used in (Celik et al, 2009;Patton et al, 2013;Rozario et al, 2009;Sharp et al, 2011;Wang, Barkana, & Sarkar, 2010;. For a purely spatial error in two dimensional reaching tasks, measurements with different gains have been performed (Patton et al, 2013; and efforts to calculate an optimal gain value from this data have been made (Parmar & Patton, 2015).…”

Error augmentation feedback for lateral weight shifting

“…There is evidence, though, that altering visual feedback affects balance performance [6,7]. In arm reaching tasks, augmenting the visual feedback position error promotes temporary performance effects for new tasks [8,9]. Error was measured as the distance from a straight-line path between the starting point and target and was visually augmented to encourage elimination of deviations from this path.…”

“…Error was measured as the distance from a straight-line path between the starting point and target and was visually augmented to encourage elimination of deviations from this path. Error augmentation helped speed subjects' adaptation to a rotation in the visual feedback [8,9]. The effects of altering biofeedback in this manner are unknown for mobility and balance tasks [10].…”