title: Vibration influences haptic perception of surface compliance during walking.
abstract: BACKGROUND
  The haptic perception of ground compliance is used for stable regulation of dynamic posture and the control of locomotion in diverse natural environments. Although rarely investigated in relation to walking, vibrotactile sensory channels are known to be active in the discrimination of material properties of objects and surfaces through touch. This study investigated how the perception of ground surface compliance is altered by plantar vibration feedback.
  
  
  RESULTS
  Subjects walked in shoes over a rigid floor plate that provided plantar vibration feedback, and responded indicating how compliant it felt, either in subjective magnitude or via pairwise comparisons. In one experiment, the compliance of the floor plate was also varied. Results showed that perceived compliance of the plate increased monotonically with vibration feedback intensity, and depended to a lesser extent on the temporal or frequency distribution of the feedback. When both plate stiffness (inverse compliance) and vibration amplitude were manipulated, the effect persisted, with both factors contributing to compliance perception. A significant influence of vibration was observed even for amplitudes close to psychophysical detection thresholds.
  
  
  CONCLUSIONS
  These findings reveal that vibrotactile sensory channels are highly salient to the perception of surface compliance, and suggest that correlations between vibrotactile sensory information and motor activity may be of broader significance for the control of human locomotion than has been previously acknowledged.
authors.affiliation: Centre for Intelligent Machines and CIRMMT, McGill University, Montreal, Quebec, Canada. yon@cim.mcgill.ca
authors.forename: Yon
authors.initials: Y
authors.lastname: Visell
authors.forename: Bruno L
authors.initials: BL
authors.lastname: Giordano
authors.forename: Guillaume
authors.initials: G
authors.lastname: Millet
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: Cooperstock
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D002138:Calibration; D003187:Compliance; D025461:Feedback, Physiological; D006801:Humans; D010465:Perception / Q000502:physiology*; D010812:Physical Stimulation; D011597:Psychomotor Performance; D013499:Surface Properties; D014110:Touch / Q000502:physiology*; D014732:Vibration; D016138:Walking / Q000502:physiology*