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Evaluation of Learning Associated with Multiple Exposures to Computerized Dynamic PosturographyComputerized dynamic posturography has been used to quantitatively assess the time course of functional sensorimotor recovery after exposure to spaceflight or to groundbased analogs such as head-down bed rest. An assessment of balance recovery may be confounded as subjects develop new strategies through repeated exposures to test paradigms. The purpose of this control study was to characterize the learning effects of sensory organization and motor control tests across multiple sessions. METHODS: Twenty-eight healthy subjects were tested over four sessions. To examine the effects of between-session interval, subjects were assigned to one of four groups in which the interval between the 1 st and 2nd sessions was 7 (+/- 1) days, 14 (+/-1) days, 28 (+/-2) days, or 56 (+/-3) days. The interval between remaining sessions was 28 (+/-4) days. Peak-to-peak anterior-posterior sway was measured during standard Sensory Organization Tests (SOTs) using either fixed or unstable sway-referenced support with eyes open, eyes closed, or sway-referenced vision. Sway was also measured during modified SOTs using eyes-closed conditions with either static or dynamic head tilts. Postural recovery to unexpected support surface perturbations (translations or rotations) was measured during Motor Control Tests. The test order was block randomized across subjects. RESULTS: The learning effects varied with test condition. There were no measurable differences with a stable support surface. The more challenging conditions (unstable support surface with and without head tilts) led to greater differences and took more trials to stabilize. The effect of time interval between the first two sessions was negligible across conditions. Evidence suggested that learning carried across similar conditions (such as unstable support SOTs). DISCUSSION: Familiarization session and/or trials are recommended to minimize learning effects when characterizing functional recovery after exposure to altered sensory environments. The number of practice trials required depends on task difficulty and similarity across conditions. Learning statement: This presentation will review the learning effects of computerized d
Document ID
20090038931
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Dean, S. Lance
(Wyle Labs., Inc. Houston, TX, United States)
Paloski, William H.
(Houston Univ. Houston, TX, United States)
Taylor, Laura C.
(Wyle Labs., Inc. Houston, TX, United States)
Vanya, Robert D.
(Wyle Labs., Inc. Houston, TX, United States)
Feiveson, Alan H.
(NASA Johnson Space Center Houston, TX, United States)
Wood, Scott J.
(Universities Space Research Association Houston, TX, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2009
Subject Category
Aerospace Medicine
Report/Patent Number
JSC-CN-19133
Meeting Information
Meeting: 81st Annual Scientific Aerospace Medical Association Meeting
Location: Phoenix,AZ
Country: United States
Start Date: May 9, 2010
End Date: May 13, 2010
Distribution Limits
Public
Copyright
Other

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