title: The importance of visual feedback on the accuracy of jaw and finger positioning in man.
abstract: The anatomical position of the mandible means that direct visual feedback is not possible. To clarify the role of visual information, several jaw- and finger-positioning tasks were designed, both in a 'free-movement' and an 'isolated' (arm or head fixed) state, with or without a visual feedback display of the target position. The subjects had to position the mandible or the index finger of the preferred hand on to a movable metal bar and to maintain a defined position coinciding with the target level provided on an oscilloscope screen. The position signal was tape recorded and computer analysed off-line. Digital filtering differentiated between the drift and the oscillations around the target (root mean square). The results demonstrated a lack of precision in the free-movement, finger-positioning task after withdrawal of visual feedback. For jaw opening and closing muscles, position control was less impaired when a visual feedback display was abolished. It was suggested that the efficiency of jaw positioning is not primarily determined by visual feedback.
authors.affiliation: Department of Periodontology, Faculty of Medicine, Catholic University, Leuven, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Jacobs
authors.forename: D
authors.initials: D
authors.lastname: van Steenberghe
authors.forename: A
authors.initials: A
authors.lastname: Schotte
mesh_terms: D000328:Adult; D001676:Biofeedback, Psychology / Q000502:physiology*; D003463:Cues; D003626:Data Display; D005260:Female; D005385:Fingers / Q000502:physiology*; D006801:Humans; D007103:Immobilization; D008297:Male; D008334:Mandible / Q000502:physiology*; D008410:Masticatory Muscles / Q000502:physiology; D009068:Movement; D009132:Muscles / Q000502:physiology; D009991:Oscillometry; D011434:Proprioception / Q000502:physiology*; D011597:Psychomotor Performance; D016683:Supine Position; D014785:Vision, Ocular