Postural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance response

Hdl Handle:
http://hdl.handle.net/10545/304845
Title:
Postural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance response
Authors:
Osler, Callum J.; Tersteeg, M. C. A.; Reynolds, Raymond Francis; Loram, Ian D.
Abstract:
Circumstances may render the consequence of falling quite severe, thus maximising the motivation to control postural sway. This commonly occurs when exposed to height and may result from the interaction of many factors, including fear, arousal, sensory information and perception. Here, we examined human vestibular-evoked balance responses during exposure to a highly threatening postural context. Nine subjects stood with eyes closed on a narrow walkway elevated 3.85 m above ground level. This evoked an altered psycho-physiological state, demonstrated by a twofold increase in skin conductance. Balance responses were then evoked by galvanic vestibular stimulation. The sway response, which comprised a whole-body lean in the direction of the edge of the walkway, was significantly and substantially attenuated after ~800 ms. This demonstrates that a strong reason to modify the balance control strategy was created and subjects were highly motivated to minimise sway. Despite this, the initial response remained unchanged. This suggests little effect on the feedforward settings of the nervous system responsible for coupling pure vestibular input to functional motor output. The much stronger, later effect can be attributed to an integration of balance-relevant sensory feedback once the body was in motion. These results demonstrate that the feedforward and feedback components of a vestibular-evoked balance response are differently affected by postural threat. Although a fear of falling has previously been linked with instability and even falling itself, our findings suggest that this relationship is not attributable to changes in the feedforward vestibular control of balance.
Affiliation:
University of Birmingham, School of Sport and Exercise Sciences, College of Life and Environmental Sciences; Manchester Metropolitan University, Manchester, Institute for Biomedical Research into Human Movement and Health
Citation:
Postural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance response 2013, 38 (8):3239 European Journal of Neuroscience
Publisher:
Wiley
Journal:
European Journal of Neuroscience
Issue Date:
2013
URI:
http://hdl.handle.net/10545/304845
DOI:
10.1111/ejn.12336
Additional Links:
http://doi.wiley.com/10.1111/ejn.12336
Type:
Research Report
Language:
en
ISSN:
0953816X
Appears in Collections:
Biological Sciences Research Group

Full metadata record

DC FieldValue Language
dc.contributor.authorOsler, Callum J.en
dc.contributor.authorTersteeg, M. C. A.en
dc.contributor.authorReynolds, Raymond Francisen
dc.contributor.authorLoram, Ian D.en
dc.date.accessioned2013-10-31T18:52:23Z-
dc.date.available2013-10-31T18:52:23Z-
dc.date.issued2013-
dc.identifier.citationPostural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance response 2013, 38 (8):3239 European Journal of Neuroscienceen
dc.identifier.issn0953816X-
dc.identifier.doi10.1111/ejn.12336-
dc.identifier.urihttp://hdl.handle.net/10545/304845-
dc.description.abstractCircumstances may render the consequence of falling quite severe, thus maximising the motivation to control postural sway. This commonly occurs when exposed to height and may result from the interaction of many factors, including fear, arousal, sensory information and perception. Here, we examined human vestibular-evoked balance responses during exposure to a highly threatening postural context. Nine subjects stood with eyes closed on a narrow walkway elevated 3.85 m above ground level. This evoked an altered psycho-physiological state, demonstrated by a twofold increase in skin conductance. Balance responses were then evoked by galvanic vestibular stimulation. The sway response, which comprised a whole-body lean in the direction of the edge of the walkway, was significantly and substantially attenuated after ~800 ms. This demonstrates that a strong reason to modify the balance control strategy was created and subjects were highly motivated to minimise sway. Despite this, the initial response remained unchanged. This suggests little effect on the feedforward settings of the nervous system responsible for coupling pure vestibular input to functional motor output. The much stronger, later effect can be attributed to an integration of balance-relevant sensory feedback once the body was in motion. These results demonstrate that the feedforward and feedback components of a vestibular-evoked balance response are differently affected by postural threat. Although a fear of falling has previously been linked with instability and even falling itself, our findings suggest that this relationship is not attributable to changes in the feedforward vestibular control of balance.en
dc.language.isoenen
dc.publisherWileyen
dc.relation.urlhttp://doi.wiley.com/10.1111/ejn.12336en
dc.rightsArchived with thanks to European Journal of Neuroscienceen
dc.subjectFearen
dc.subjectHuman balanceen
dc.subjectReflexen
dc.subjectSwayen
dc.subjectVestibular stimulationen
dc.titlePostural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance responseen
dc.typeResearch Reporten
dc.contributor.departmentUniversity of Birmingham, School of Sport and Exercise Sciences, College of Life and Environmental Sciencesen
dc.contributor.departmentManchester Metropolitan University, Manchester, Institute for Biomedical Research into Human Movement and Healthen
dc.identifier.journalEuropean Journal of Neuroscienceen
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