@misc{DietrichHeidgerSchnieppetal., author = {Dietrich, Haike and Heidger, F. and Schniepp, Roman and MacNeilage, Paul R. and Glasauer, Stefan and W{\"u}hr, Max}, title = {Head motion predictability explains activity-dependent suppression of vestibular balance control}, series = {Scientific Reports}, volume = {10}, journal = {Scientific Reports}, issn = {2045-2322}, doi = {10.1038/s41598-019-57400-z}, abstract = {Vestibular balance control is dynamically weighted during locomotion. this might result from a selective suppression of vestibular inputs in favor of a feed-forward balance regulation based on locomotor efference copies. The feasibility of such a feed-forward mechanism should however critically depend on the predictability of head movements (HMP) during locomotion. To test this, we studied in 10 healthy subjects the differential impact of a stochastic vestibular stimulation (SVS) on body sway (center-of-pressure, COP) during standing and walking at different speeds and compared it to activity-dependent changes in HMp. SVS-cop coupling was determined by correlation analysis in frequency and time domains. HMP was quantified as the proportion of head motion variance that can be explained by the average head trajectory across the locomotor cycle. SVS-COP coupling decreased from standing to walking and further dropped with faster locomotion. Correspondingly, HMP increased with faster locomotion. Furthermore, SVS-COP coupling depended on the gait-cycle-phase with peaks corresponding to periods of least HMP. These findings support the assumption that during stereotyped human self-motion, locomotor efference copies selectively replace vestibular cues, similar to what was previously observed in animal models.}, language = {en} } @misc{DietrichHeidgerSchnieppetal., author = {Dietrich, Haike and Heidger, F. and Schniepp, Roman and MacNeilage, Paul R. and Glasauer, Stefan and W{\"u}hr, Max}, title = {Head motion predictability explains phase-and speed-dependent suppression of vestibular balance control during walking}, series = {Elsevier}, volume = {131}, journal = {Elsevier}, number = {4}, edition = {1.}, publisher = {Elsevier}, doi = {10.1016/j.clinph.2019.12.083}, pages = {e219 -- e220}, abstract = {Methods: Body sway was analyzed by measuring the center of pressure (CoP) in 10 healthy participants on a pressure-sensitive treadmill during standing and walking at 0.4 or 0.8 m/s. Continuous SVS (0-25 Hz; peak amplitude at±4.5 mA) was delivered by a bipolar binaural electrode configuration over the mastoid processes to evoke postural responses in the roll plane. Time-dependent coherence between SVS and medio-lateral body sway was analyzed to examine the dynamic impact of vestibular cues during locomotion. HMP was estimated using a previously established model (MacNeilage and Glasauer, 2017). Results: SVS-CoP coherence decreased from standing to slow walking and further decreased with increasing locomotor speed (p< 0.001). Correspondingly, HMP increased with faster locomotion (p= 0.001). SVS-CoP coherence depended on the gait cycle phase with two distinct peaks occurring at 25 …}, language = {en} }