title: Surface electrical stimulation perturbation context determines the presence of error reduction in swallowing hyolaryngeal kinematics.
abstract: OBJECTIVE
  Error-based learning (EBL) involves gradually reducing movement errors caused by a perturbation. When the perturbation has been unexpectedly removed, exaggerated movements occur in the opposite direction of a perturbation effect, known as aftereffects. Our goal was to determine whether the perturbation type impacts error reduction or aftereffects in swallowing hyolaryngeal kinematics.
  
  
  METHODS
  We perturbed peak hyolaryngeal elevation during swallowing in 16 healthy adults with surface electrical stimulation (SES) in 2 different ways during videofluoroscopy: intermittent SES (I-SES) was applied only during swallowing, and continuous SES (C-SES) was applied during swallowing and during interswallow intervals. In C-SES and I-SES, the onset and offset of the perturbation were unmasked.
  
  
  RESULTS
  Only the C-SES perturbation caused error reduction (gradually increasing peak elevation). Aftereffects were absent in both perturbations, unlike findings from our previous study with masked perturbation. Furthermore, the duration of laryngeal vestibule closure (dLVC) increased during the I-SES perturbation but was unchanged during C-SES perturbation.
  
  
  CONCLUSIONS
  EBL of swallowing airway protection events was strongly influenced by the context of the perturbation. These findings also elucidate how the relationship among critical swallowing airway protection events (hyoid peak, laryngeal peak, and dLVC) can be modified during EBL.
authors.forename: Ianessa A
authors.initials: IA
authors.lastname: Humbert
authors.forename: Heather
authors.initials: H
authors.lastname: Christopherson
authors.forename: Akshay
authors.initials: A
authors.lastname: Lokhande
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology*; D003679:Deglutition / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D007013:Hypopharynx / Q000502:physiology*; D007830:Larynx / Q000502:physiology; D008297:Male; D011897:Random Allocation; D012016:Reference Values; D014741:Video Recording; D055815:Young Adult