title: Eye Gaze Correlates of Motor Impairment in VR Observation of Motor Actions.
abstract: BACKGROUND
  This article is part of the Focus Theme of Methods of Information in Medicine on "Methodologies, Models and Algorithms for Patients Rehabilitation".
  
  
  OBJECTIVE
  Identify eye gaze correlates of motor impairment in a virtual reality motor observation task in a study with healthy participants and stroke patients.
  
  
  METHODS
  Participants consisted of a group of healthy subjects (N = 20) and a group of stroke survivors (N = 10). Both groups were required to observe a simple reach-and-grab and place-and-release task in a virtual environment. Additionally, healthy subjects were required to observe the task in a normal condition and a constrained movement condition. Eye movements were recorded during the observation task for later analysis.
  
  
  RESULTS
  For healthy participants, results showed differences in gaze metrics when comparing the normal and arm-constrained conditions. Differences in gaze metrics were also found when comparing dominant and non-dominant arm for saccades and smooth pursuit events. For stroke patients, results showed longer smooth pursuit segments in action observation when observing the paretic arm, thus providing evidence that the affected circuitry may be activated for eye gaze control during observation of the simulated motor action.
  
  
  CONCLUSIONS
  This study suggests that neural motor circuits are involved, at multiple levels, in observation of motor actions displayed in a virtual reality environment. Thus, eye tracking combined with action observation tasks in a virtual reality display can be used to monitor motor deficits derived from stroke, and consequently can also be used for rehabilitation of stroke patients.
authors.affiliation: Júlio Alves, Madeira-ITI, Polo Científico e Tecnológico da Madeira, Floor -2, Caminho da Penteada, 9020-105 Funchal, Portugal, E-mail: juliomalves@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Alves
authors.forename: A
authors.initials: A
authors.lastname: Vourvopoulos
authors.forename: A
authors.initials: A
authors.lastname: Bernardino
authors.forename: S
authors.initials: S
authors.lastname: Bermúdez I Badia
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003198:Computer Simulation; D005123:Eye / Q000033:anatomy & histology*; D005133:Eye Movements; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D009069:Movement Disorders / Q000175:diagnosis*; D012046:Rehabilitation / Q000379:methods*; D020521:Stroke / Q000175:diagnosis*; D000071939:Stroke Rehabilitation / Q000379:methods
keywords: Action observation; eye movements; stroke; virtual reality