Free Energy Principle in Human Postural Control System: Skin Stretch Feedback Reduces the Entropy

Details

• Personal Author:
  DeBuys C ; Hur P ; Pan Y-T
• Description:
  Human upright standing involves an integration of multiple sensory inputs such as vision, vestibular and somatosensory systems. It has been known that sensory deficits worsen the standing balance. However, how the modulation of sensory information contributes to postural stabilization still remains an open question for researchers. The purpose of this work was to formulate the human standing postural control system in the framework of the free-energy principle, and to investigate the efficacy of the skin stretch feedback in enhancing the human standing balance. Previously, we have shown that sensory augmentation by skin stretch feedback at the fingertip could modulate the standing balance of the people with simulated sensory deficits. In this study, subjects underwent ten 30-second trials of quiet standing balance with and without skin stretch feedback. Visual and vestibular sensory deficits were simulated by having each subject close their eyes and tilt their head back. We found that sensory augmentation by velocity-based skin stretch feedback at the fingertip reduced the entropy of the standing postural sway of the people with simulated sensory deficits. This result aligns with the framework of the free energy principle which states that a self-organizing biological system at its equilibrium state tries to minimize its free energy either by updating the internal state or by correcting body movement with appropriate actions. The velocity-based skin stretch feedback at the fingertip may increase the signal-to-noise ratio of the sensory signals, which in turn enhances the accuracy of the internal states in the central nervous system. With more accurate internal states, the human postural control system can further adjust the standing posture to minimize the entropy, and thus the free energy. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Musculoskeletal System Occupational Health Safety
• Keywords:
  Biomechanics Central Nervous System Posture Sensory Disorders Sensory Perceptual Processes Vestibular Disorders Visual Perception
• ISSN:
  2045-2322
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 6 ; Texas
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  9
• NIOSHTIC Number:
  nn:20068480
• Citation:
  Sci Rep 2019 Nov; 9:16870
• Contact Point Address:
  Pilwon Hur, Texas A&M University, Department of Mechanical Engineering, College Station, TX, 77843, USA
• Email:
  pilwonhur@tamu.edu
• Federal Fiscal Year:
  2020
• Performing Organization:
  University of Texas Health Science Center, Houston
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Scientific Reports
• End Date:
  20250630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ac115a30078a561f910663b7a51fd46b0472eae5bdd76060042d77a8b4b317b51baf959a648dcbab64fbe81eba21e23f45ac76cdedd613b25cdff4d1e0d1ede9
• Download URL:
  https://stacks.cdc.gov/view/cdc/207097/cdc_207097_DS1.pdf
• File Type:
  [PDF - 1.86 MB ]