Exploring coordination dynamics of the postural system with real-time visual feedback.
Differential performance over a wide range of possible postural coordination modes was investigated using 16 ankle-hip relative phase patterns from 0 degrees to 337.5 degrees. Participants were instructed to produce each coordination mode with and without real time visual feedback. Feedback consisted of a Lissajous figure indicating the discrepancy between actual and requested ankle-hip relative phase. The results showed: (1) the presence of a unique attractor around the anti-phase pattern (relative phase approximately 180 degrees); (2) performance was similar with and without visual feedback; (3) the absence of an attractor for the in-phase pattern (relative phase approximately 20 degrees). The third result is not consistent with previous research in which both in-phase and anti-phase patterns emerged when they were not imposed [B.G. Bardy, L. Martin, T.A. Stoffregen, R.J. Bootsma, Postural coordination modes considered as emergent phenomena, J. Exp. Psychol. Hum. Percept. Perform. 25 (1999) 1284-1301; B.G. Bardy, O. Oullier, R.J. Bootsma, T.A. Stoffregen, Dynamics of human postural transitions, J. Exp. Psychol. Hum. Percept. Perform. 28 (1999) 499-514]. This finding indicates the strong dependency to task variation and instructions of postural pattern formation.
Faugloire
Elise
E
Research Center in Sport Sciences, UFR STAPS, University of Paris Sud XI, Batiment 335, 91405 Orsay, France. elise.faugloire@staps.u-psud.fr
Bardy
Benoît G
BG
Merhi
Omar
O
Stoffregen
Thomas A
TA
D000328:Adult; D000843:Ankle Joint / Q000502:physiology; D005246:Feedback / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*