Learning and generalization in an isometric visuomotor task

Rotella, Michele F.; Nisky, Ilana; Koehler, Margaret; Rinderknecht, Mike D.; Bastian, Amy J.; Okamura, Allison M.

doi:10.1152/jn.00255.2014

Cited by 24 publications

(27 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A common way to assess the adaptation and the construction of an internal model is by examining aftereffects when the perturbation is unexpectedly removed. Another approach is to test for transfer of adaptation to a different workspace (Shadmehr and Mussa-Ivaldi, 1994 ; Rotella et al, 2015 ), a different context (Kluzik et al, 2008 ), or a different task (Shadmehr and Mussa-Ivaldi, 1994 ; Botzer and Karniel, 2013 ). Investigating aftereffects and transfer of adaptation reveals how the new kinematics or dynamics are represented by the motor system.…”

Section: Introductionmentioning

confidence: 99%

Neglect-Like Effects on Drawing Symmetry Induced by Adaptation to a Laterally Asymmetric Visuomotor Delay

Avraham

Mussa-Ivaldi

et al. 2018

Front. Hum. Neurosci.

Self Cite

View full text Add to dashboard Cite

In daily interactions, our sensorimotor system accounts for spatial and temporal discrepancies between the senses. Functional lateralization between hemispheres causes differences in attention and in the control of action across the left and right workspaces. In addition, differences in transmission delays between modalities affect movement control and internal representations. Studies on motor impairments such as hemispatial neglect syndrome suggested a link between lateral spatial biases and temporal processing. To understand this link, we computationally modeled and experimentally validated the effect of laterally asymmetric delay in visual feedback on motor learning and its transfer to the control of drawing movements without visual feedback. In the behavioral experiments, we asked healthy participants to perform lateral reaching movements while adapting to delayed visual feedback in either left, right, or both workspaces. We found that the adaptation transferred to blind drawing and caused movement elongation, which is consistent with a state representation of the delay. However, the pattern of the spatial effect varied between conditions: whereas adaptation to delay in only the left workspace or in the whole workspace caused selective leftward elongation, adaptation to delay in only the right workspace caused drawing elongation in both directions. We simulated arm movements according to different models of perceptual and motor spatial asymmetry in the representation of delay and found that the best model that accounts for our results combines both perceptual and motor asymmetry between the hemispheres. These results provide direct evidence for an asymmetrical processing of delayed visual feedback that is associated with both perceptual and motor biases that are similar to those observed in hemispatial neglect syndrome.

show abstract

Section: Introductionmentioning

confidence: 99%

Neglect-Like Effects on Drawing Symmetry Induced by Adaptation to a Laterally Asymmetric Visuomotor Delay

Avraham

Mussa-Ivaldi

et al. 2018

Front. Hum. Neurosci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Several previous studies involved learning in isometric conditions (e.g., Liu et al 2006;Mah and Mussa-Ivaldi 2003;Rotella et al 2015;Todorov et al 1997); however, they did not test whether and how the learned motor skills in the isometric scenario would transfer to actual movements. In contrast, our study 1) involves exploiting the adaptive processes in a motionless setting to teach motor skills that could be transferable to a corresponding physical task and 2) evaluates movement skill of controlling/adapting to internal and external forces that were only virtually present during training.…”

mentioning

confidence: 99%

Transfer of dynamic motor skills acquired during isometric training to free motion

Tan

Bittmann

Burdet

et al. 2017

Journal of Neurophysiology

View full text Add to dashboard Cite

Recent studies have explored the prospects of learning to move without moving, by displaying virtual arm movement related to exerted force. However, it has yet to be tested whether learning the dynamics of moving can transfer to the corresponding movement. Here we present a series of experiments that investigate this isometric training paradigm. Subjects were asked to hold a handle and generate forces as their arms were constrained to a static position. A precise simulation of reaching was used to make a graphic rendering of an arm moving realistically in response to the measured interaction forces and simulated environmental forces. Such graphic rendering was displayed on a horizontal display that blocked their view to their actual (statically constrained) arm and encouraged them to believe they were moving. We studied adaptation of horizontal, planar, goal-directed arm movements in a velocity-dependent force field. Our results show that individuals can learn to compensate for such a force field in a virtual environment and transfer their new skills to the actual free motion condition, with performance comparable to practice while moving. Such nonmoving techniques should impact various training conditions when moving may not be possible. This study provided early evidence supporting that training movement skills without moving is possible. In contrast to previous studies, our study involves ) exploiting cross-modal sensory interactions between vision and proprioception in a motionless setting to teach motor skills that could be transferable to a corresponding physical task, and) evaluates the movement skill of controlling muscle-generated forces to execute arm movements in the presence of external forces that were only virtually present during training.

show abstract

“…If such a coding bias exists throughout the sensorimotor system, this imbalance would support a preference towards velocity-based learning during initial force-field adaptation and an asymmetry during the subsequent decay. Possible support for this bias may be found in a recent study by Rotella and colleagues [49]. The authors asked subjects to produce isometric hand forces which were then mapped to the position or velocity of a virtual cursor.…”

Section: Discussionmentioning

confidence: 99%

The decay of motor adaptation to novel movement dynamics reveals an asymmetry in the stability of motion state-dependent learning

2017

View full text Add to dashboard Cite

Motor adaptation paradigms provide a quantitative method to study short-term modification of motor commands. Despite the growing understanding of the role motion states (e.g., velocity) play in this form of motor learning, there is little information on the relative stability of memories based on these movement characteristics, especially in comparison to the initial adaptation. Here, we trained subjects to make reaching movements perturbed by force patterns dependent upon either limb position or velocity. Following training, subjects were exposed to a series of error-clamp trials to measure the temporal characteristics of the feedforward motor output during the decay of learning. The compensatory force patterns were largely based on the perturbation kinematic (e.g., velocity), but also showed a small contribution from the other motion kinematic (e.g., position). However, the velocity contribution in response to the position-based perturbation decayed at a slower rate than the position contribution to velocity-based training, suggesting a difference in stability. Next, we modified a previous model of motor adaptation to reflect this difference and simulated the behavior for different learning goals. We were interested in the stability of learning when the perturbations were based on different combinations of limb position or velocity that subsequently resulted in biased amounts of motion-based learning. We trained additional subjects on these combined motion-state perturbations and confirmed the predictions of the model. Specifically, we show that (1) there is a significant separation between the observed gain-space trajectories for the learning and decay of adaptation and (2) for combined motion-state perturbations, the gain associated to changes in limb position decayed at a faster rate than the velocity-dependent gain, even when the position-dependent gain at the end of training was significantly greater. Collectively, these results suggest that the state-dependent adaptation associated with movement velocity is relatively more stable than that based on position.

show abstract

Learning and generalization in an isometric visuomotor task

Cited by 24 publications

References 77 publications

Neglect-Like Effects on Drawing Symmetry Induced by Adaptation to a Laterally Asymmetric Visuomotor Delay

Neglect-Like Effects on Drawing Symmetry Induced by Adaptation to a Laterally Asymmetric Visuomotor Delay

Transfer of dynamic motor skills acquired during isometric training to free motion

The decay of motor adaptation to novel movement dynamics reveals an asymmetry in the stability of motion state-dependent learning

Contact Info

Product

Resources

About