Increased reward in ankle robotics training enhances motor control and cortical efficiency in stroke

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Increased reward in ankle robotics training
enhances motor control and cortical efficiency in
stroke

• Ronald N. Goodman, PhD Jeremy C. Rietschel, PhD
  Anindo Roy, PhD Brian C. Jung, BS Jason Diaz,
  MS Richard F. Macko, MD Larry W. Forrester, PhD

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• Aim
• Use impedance-controlled ankle robot (anklebot)
  to determine whether lower-limb robotic training
  would be enhanced with overt rewards and
  augmented feedback.
• Relevance
• Robotics is rapidly emerging as viable approach
  to enhanced motor recovery after disabling
  stroke.
• No prior studies have established explicitly
  whether reward improves rate/efficacy of
  robotics-assisted rehabilitation or produces
  neurophysiological adaptations associated with
  motor learning.

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Method

• Clinical pilot (3 wk, 9 sessions)
• 10 people with chronic hemiparetic stroke.
• Randomly assigned to high reward or low reward
  conditions.
• Training sessions (1 h)
• Seated video game using paretic ankle to hit
  moving targets with anklebot providing assistance
  only as needed.
• Assessments
• Paretic ankle motor control.
• Learning curves.
• Electroencephalography (EEG) coherence and
  spectral power during unassisted trials.
• Gait function.

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Results

• Both groups
• Changes in EEG.
• High reward group
• Faster learning curves.
• Smoother movements.
• Reduced contralesional-frontoparietal coherence.
• Reduced left-temporal spectral power.
• Increased nonparetic step length.

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Conclusion

• Combining explicit rewards with novel anklebot
  training may accelerate motor learning for
  restoring mobility.