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Project Title:  Sensorimotor adaptation following exposure to ambiguous inertial motion cues Reduce
Fiscal Year: FY 2009 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 09/01/2004  
End Date: 02/28/2009  
Task Last Updated: 05/12/2010 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wood, Scott J. Ph.D. / NASA Johnson Space Center 
Address:  2101 NASA Parkway 
Mail code SD2 
Houston , TX 77058 
Email: scott.j.wood@nasa.gov 
Phone: (281) 483-6329  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments: NOTE: PI returned to NASA JSC in January 2017. PI was at Azusa Pacific University from August 2013 – January 2017; prior to August 2013, PI was at NASA JSC. 
Co-Investigator(s)
Affiliation: 
Harm, Deborah  NASA JSC 
Clement, Gilles  Centre National de la Recherche Scientifique 
Rupert, Angus  Naval Aerospace Medical Research Laboratory 
Project Information: Grant/Contract No. NCC 9-58-NA00405 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: NRA-03-OBPR-04 
Grant/Contract No.: NCC 9-58-NA00405 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Flight Assignment/Project Notes: NOTE: End date changed to 2/28/2009, from 8/31/2008, per NSBRI (10/7/08)

Task Description: The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Our general hypothesis is that the central nervous system utilizes both multi-sensory integration and frequency segregation as neural strategies to resolve the ambiguity of tilt and translation stimuli. Movement in an altered gravity environment, such as weightlessness without a stable gravity reference, results in new patterns of sensory cues. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth's gravity. The primary goals of this ground-based research investigation were to explore physiological mechanisms and operational implications of disorientation and tilt-translation disturbances reported by crewmembers during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during passive tilt and translation motion paradigms.

Aim 1 was to examine the effects of stimulus frequency (0.01 - 0.6 Hz ) on adaptive changes in eye movements, motion perception and cognition during combined tilt and translation motion profiles. We hypothesized that adaptation of otolith-mediated responses will be greatest in the mid-frequency range where there is a tilt-translation crossover. Our findings emphasized differences in the neural processing to distinguish tilt and translation between eye movements and motion perception. Specifically, during dynamic linear stimuli in the absence of canal and visual input, a change in stimulus frequency alone elicits similar changes in the amplitude of both self motion perception and eye movements. However, in contrast to the eye movements, the phase of both perceived tilt and translation motion is not altered by stimulus frequency over this limited range. Our findings also suggest that the frequency at which there was a crossover of perceived tilt and translation gains appeared to vary across different motion paradigms (e.g., near 0.3 Hz during off-vertical axis rotation and near 0.15 Hz during sled translation).

Adaptation experiments conducted below this cross-over frequency using the 'vision-aligned' paradigm have resulted in modest changes to both eye movements and motion perception, consistent with our first hypothesis. Adaptation experiments conducted around this cross-over frequency range using the 'GIF-aligned' paradigm demonstrated a significant effect of stimulus frequency on both motion sickness and spatial cognitive performance.

Aim 2 was to examine changes in control errors during a closed-loop nulling task before and after tilt-translation adaptation. We hypothesized that the ability to control tilt orientation will be compromised following tilt-translation adaptation, with increased control errors corresponding to changes in self-motion perception. Roll tilt nulling was implemented using the both step and pseudorandom stimuli in darkness. Our findings suggest that these types of manual control tasks are sensitive to underlying changes in sensorimotor physiology, and specifically to changes in the brain's interpretation of linear acceleration stimuli.

Aim 3 was to evaluate how a tactile prosthesis might improve control performance. A simple 4 electromechanical tactor system was developed that provided 6 threshold levels of orientation information. We also examined the influence of vibrotactile feedback during computerized posturography. A significant reduction in RMS error (p<0.05) was observed using this simple tactile prosthesis, both during manual and balance control tasks. These results are promising in that a fairly simple device with as few as 4 tactors may prove useful to significantly improve landing performance.

Aim 4 was to examine how spatial awareness is impaired with changing gravitational cues during parabolic flight, and the extent to which vibrotactile feedback of orientation can be used to help improve spatial awareness. Our findings suggest that tactile cueing may improve navigation in operational environments, such as extravehicular activities on a lunar surface. This type of sensory feedback may also prove beneficial as a navigation aid in patient populations, providing non-visual, non-auditory feedback of orientation or desired direction heading.

Research Impact/Earth Benefits: This project provides insight into adaptive mechanisms of otolith function, in particular as they relate to one's perception of motion and cognitive function. The results of this study are relevant therefore to vestibular pathophysiology, and understanding compensatory processes following loss or disruption of otolith function in clinical applications. The closed-loop nulling tasks employed by our experiment team provides a new means of addressing the functional implications of vestibular loss, for example, characterizing risks associated with civilian piloting or automobile driving following vestibular loss. Finally, the development of simple tactile displays is applicable to balance prosthesis applications for vestibular loss patients and the elderly to mitigate risks due to falling or loss of orientation.

Task Progress & Bibliography Information FY2009 
Task Progress: During the final year of the grant we completed three major studies. The first study compared roll-tilt and lateral translation motion perception in 12 subjects across four different motion paradigms: Off-Vertical Axis Rotation, Variable Radius Centrifugation, Earth-horizontal Axis Rotation, and Lateral Sled Translation. The second study utilized a Tilt-Translation Sled as a space-flight sensorimotor analog to examine adaptive changes following exposure to conflicting tilt-translation stimuli. Fourteen subjects were tilted within a lighted enclosure that simultaneously translated at one of 3 frequencies. Each subject participated in 6 sessions including a familiarization session, passive pitch at 0.15, 0.3 and 0.6 Hz and roll at 0.3 Hz, and active pitch at 0.3 Hz. A new spatial cognitive test was developed from previous match-to-sample and mental rotation tasks. The third study utilized parabolic flight to examine acute changes in spatial navigation during the weightless phase. Six student researchers participated on the Reduced Gravity Student Program, using a virtual spatial navigation task during parabolic flight and during baseline ground tests. In both the sled and parabolic analog studies, vibrotactile feedback was implemented as a sensory countermeasure to improve spatial awareness.

Bibliography Type: Description: (Last Updated: 10/25/2021)  Show Cumulative Bibliography Listing
 
Articles in Peer-reviewed Journals Holly JE, Wood SJ, McCollum G. "Phase-linking and the perceived motion during off-vertical axis rotation." Biol Cybern. 2010 Jan;102(1):9-29. PMID: 19937069 , Jan-2010
Articles in Peer-reviewed Journals Wood SJ, Reschke MF, Sarmiento LA, Clément G. "Tilt and translation motion perception during off-vertical axis rotation." Exp Brain Res. 2007 Sep;182(3):365-77. PMID: 17565488 , Sep-2007
NASA Technical Documents Wood SJ. "Reduced gravity education flight program." Houston, Tex. : NASA Lyndon B. Johnson Space Center, p., 27-28, 2009. , Dec-2009
Papers from Meeting Proceedings Clement G, Harm, DL, Rupert AH, Beaton KH, Wood SJ. "Ambiguous tilt and translation motion cues in astronauts after space flight." Human Research program Investigators' Workshop, League City, Tex.., February 2-4, 2009.

Human Research Program Investigators' Workshop, 2009. , Feb-2009

Significant Media Coverage Myers C. "What's a sensor belt? Three-part news story on the NSBRI student project on the parabolic flight program." KTRK-TV, Houston, Texas, April 2009. http://abclocal.go.com/ktrk/story?section=news/health&id=6632255 , Apr-2009
Significant Media Coverage Jeffs B. "Scientist probes workings of the inner ear." JSC Roundup , p. 10-11, Vol 47, No 8, August 2008., Aug-2008
Project Title:  Sensorimotor adaptation following exposure to ambiguous inertial motion cues Reduce
Fiscal Year: FY 2007 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 09/01/2004  
End Date: 02/28/2009  
Task Last Updated: 02/01/2008 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wood, Scott J. Ph.D. / NASA Johnson Space Center 
Address:  2101 NASA Parkway 
Mail code SD2 
Houston , TX 77058 
Email: scott.j.wood@nasa.gov 
Phone: (281) 483-6329  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments: NOTE: PI returned to NASA JSC in January 2017. PI was at Azusa Pacific University from August 2013 – January 2017; prior to August 2013, PI was at NASA JSC. 
Co-Investigator(s)
Affiliation: 
Harm, Deborah  NASA JSC 
Clement, Gilles  Centre National de la Recherche Scientifique 
Rupert, Angus  Naval Aerospace Medical Research Laboratory 
Project Information: Grant/Contract No. NCC 9-58-NA00405 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2003 Biomedical Research & Countermeasures 03-OBPR-04 
Grant/Contract No.: NCC 9-58-NA00405 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Flight Assignment/Project Notes: NOTE: End date changed to 2/28/2009, from 8/31/2008, per NSBRI (10/7/08)

Task Description: The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Our general hypothesis is that the central nervous system utilizes both multi-sensory integration and frequency segregation as neural strategies to resolve the ambiguity of tilt and translation stimuli. Movement in an altered gravity environment, such as weightlessness without a stable gravity reference, results in new patterns of sensory cues. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth’s gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of disorientation and tilt-translation disturbances reported by crewmembers during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during passive tilt and translation motion paradigms.

Our first specific aim is to examine the effects of stimulus frequency and different patterns of inertial sensory cues on adaptive changes in eye movements and motion perception during combined tilt and translation motion profiles. Our first hypothesis is that adaptation of otolith-mediated eye movement and perceptual responses will be greatest in the mid-frequency range where there is a crossover of tilt and translation otolith-mediated responses. We are testing this hypothesis by exposing subjects to various combinations of tilt and translation motion profiles over the frequency range from 0.01 Hz to 0.6 Hz. Changes in eye movement and perceptual tilt responses are determined by comparing pre- and post-adaptation runs performed in darkness.

Baseline eye movements and motion perception elicited during various combinations of tilt and translation stimuli have compared across multiple acceleration platforms. Constant velocity off-vertical axis rotation (OVAR) provides a continually changing head and body orientation relative to gravity where the equivalent linear acceleration is a function of tilt angle and the frequency is a function of rotation rate. Variable radius centrifugation (VRC) is another technique that allows low frequency linear acceleration by combining the centripetal acceleration and sled acceleration to achieve the desired resultant linear acceleration amplitude. Tilting about an Earth horizontal axis and translation along a linear track or sled are the final two motion paradigms that have been used to characterize how the brain interprets linear acceleration at different frequencies. The key findings of these studies have been that the neural processing to distinguish tilt and translation differs between eye movements and motion perception. These findings have an important impact in assessing tilt-translation disturbances following space flight or the adaptation experiments that are planned for the final year.

Adaptive changes using a ‘vision aligned’ paradigm have been conducted by exposing subjects to matching tilt self motion with conflicting visual surround translation. The optimal phase relationship between body tilt and scene translation was examined at 0.1 Hz in the pitch plane using JSC’s Tilt-Translation Device (TTD, designed to recreate post-flight orientation disturbances. This study demonstrated that a 180 deg phase relationship should be employed during subsequent studies, although asymmetric stimuli may provide the most robust changes in the pitch plane. Similar studies in the roll plane are in progress at Legacy Health System in Portland OR using a hydraulic powered tilt chair with a chair-mounted horizontal optokinetic stimulus. Finally, a new Tilt-Translation Sled was recently installed at JSC to implement a ‘GIF aligned’ paradigm in which the chair will tilt within an enclosure that will simultaneously translate, resulting in a mismatch in which the canals and vision signal tilt while otoliths do not.

Our second specific aim is to examine changes in control errors during a closed-loop nulling task before and after tilt-translation adaptation. We predict the ability to control tilt orientation will be compromised following tilt-translation adaptation, with increased control errors corresponding to changes in self-motion perception. Roll tilt nulling was implemented using the hydraulic tilt chair with both step and pseudorandom stimuli in darkness. Future studies are planned using tilt nulling with a constantly moving visual scene to simulate the brown-out conditions that were encountered during the initial lunar landings.

Our third specific aim is to evaluate how a tactile prosthesis might improve control performance. A simple 4 electromechanical tactor system was developed that provided 6 threshold levels of orientation information. We also examined the influence of vibrotactile feedback during computerized posturography. A significant reduction in RMS error (p<0.05) was observed using this simple tactile prosthesis, both during manual and balance control tasks. These results are promising in that a fairly simple device with as few as 4 tactors may prove useful to significantly improve landing performance. Both studies demonstrate how a tactile prosthesis can be optimized with feed-forward projections using velocity information.

During the final year, experiments integrating all three specific aims will be conducted using the Tilt-Translation sled at JSC to provide the ‘GIF-aligned’ paradigm and the hydraulic chair at Legacy to provide the ‘visual-aligned’ paradigm. The results of this study will contribute to the refinement of the tactile prosthesis to improve spatial orientation and navigation on different acceleration platforms, including landing systems used for return to Earth after long duration space travel or landing systems used during space exploration missions.

Research Impact/Earth Benefits: This project will provide insight into adaptive mechanisms of otolith function, in particular as they relate to one’s perception of motion and gaze stabilization reflexes. The results of this study will be relevant therefore to vestibular pathophysiology, and understanding compensatory processes following loss or disruption of otolith function in clinical applications. The closed-loop nulling tasks employed by our experiment team will provide a new means of addressing the functional implications of vestibular loss, for example, characterizing risks associated with civilian piloting or automobile driving following vestibular loss. Finally, the development of simple tactile displays will be applicable to balance prosthesis applications for vestibular loss patients and the elderly to mitigate risks due to falling or loss of orientation.

Task Progress & Bibliography Information FY2007 
Task Progress: Our first specific aim has focused on the effect of both stimulus frequency and different patterns of inertial motion cues on various acceleration platforms. Otolith-mediated responses during off-vertical axis rotation (OVAR) demonstrate that while a change in stimulus frequency alone elicits similar changes in the amplitude of both self motion perception and eye movements, differences in the phases suggest that neural processing strategies to distinguish tilt and translation differs between ocular and cognitive processes (Wood et al., 2007). Modeling the OVAR motion perception results is nearing completion (Holly et al, in preparation). Direct comparisons of eye movements and motion perception are also ongoing between four different motion platforms: OVAR, variable radius centrifugation, tilt about an Earth-horizontal axis and translation along a linear track. These motion paradigms will be employed in pending ESA post-flight experiments.

Initial adaptation experiments have been conducted using a visual-aligned paradigm in which passive tilt is coupled with moving scene translation. The initial study performed with JSC’s Tilt Translation Device in the pitch plane demonstrated that the visual scene otion with 180 deg phase results in a significantly reduced perceived tilt and increase linear vection and vergence eye movements compared to pre-exposure tilt stimuli in darkness (O’Sullivan et al, 2006). A second study is in progress using roll tilt stimuli coupled with a horizontally moving visual scene. Another study was implemented this past year to optimize the use of passive dynamic visual acuity as a dependent measure of visual performance changes (Wood et al, 2007).

Our second specific aim has focused on changes in control errors during a closed-loop nulling task before and after tilt-translation adaptation. Roll tilt nulling demonstrated that control performance was compromised by low-frequency bias during pseudorandom stimuli in darkness (Wood et al., 2006). Preliminary findings suggest that these types of manual control task are sensitive to underlying changes in sensorimotor physiology. A follow-up study is examining the influence of low frequency visual scene motion to simulate the effect of brown-out conditions reported during lunar landings.

Our third specific aim is to evaluate how a tactile prosthesis might improve control performance. A simple 4 electromechanical tactor system was developed that provided 6 threshold levels of orientation information. A significant reduction in RMS error (p<0.05) was observed using this simple tactile prosthesis, both during manual (Rupert et al., 2006) and balance control tasks (Wood et al., 2006). These results are promising in that a fairly simple device with as few as 4 tactors may prove useful to significantly improve landing performance.

Bibliography Type: Description: (Last Updated: 10/25/2021)  Show Cumulative Bibliography Listing
 
Articles in Peer-reviewed Journals Wood SJ, Reschke MF, Sarmiento LA, Clément G. "Tilt and translation motion perception during off-vertical axis rotation." Exp Brain Res. 2007 Sep;182(3):365-77. Epub 2007 Jun 13. PMID: 17565488 , Jun-2007
Project Title:  Sensorimotor adaptation following exposure to ambiguous inertial motion cues Reduce
Fiscal Year: FY 2006 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 09/01/2004  
End Date: 08/31/2008  
Task Last Updated: 01/08/2007 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wood, Scott J. Ph.D. / NASA Johnson Space Center 
Address:  2101 NASA Parkway 
Mail code SD2 
Houston , TX 77058 
Email: scott.j.wood@nasa.gov 
Phone: (281) 483-6329  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments: NOTE: PI returned to NASA JSC in January 2017. PI was at Azusa Pacific University from August 2013 – January 2017; prior to August 2013, PI was at NASA JSC. 
Co-Investigator(s)
Affiliation: 
Harm, Deborah  NASA JSC 
Clement, Gilles  Centre National de la Recherche Scientifique 
Rupert, Angus  Naval Aerospace Medical Research Laboratory 
Project Information: Grant/Contract No. NCC 9-58-NA00405 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2003 Biomedical Research & Countermeasures 03-OBPR-04 
Grant/Contract No.: NCC 9-58-NA00405 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Task Description: The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Our general hypothesis is that the central nervous system utilizes both multi-sensory integration and frequency segregation as neural strategies to resolve the ambiguity of tilt and translation stimuli. Movement in an altered gravity environment, such as weightlessness without a stable gravity reference, results in new patterns of sensory cues. For example, the semicircular canals, vision and neck proprioception provide information about head tilt on orbit without the normal otolith head-tilt position that is omnipresent on Earth. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth’s gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of disorientation and tilt-translation disturbances reported by crewmembers during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during passive tilt and translation motion paradigms.

Our first specific aim is to examine the effects of stimulus frequency and different patterns of inertial sensory cues on adaptive changes in eye movements and motion perception during combined tilt and translation motion profiles. Our first hypothesis is that adaptation of otolith-mediated eye movement and perceptual responses will be greatest in the mid-frequency range where there is a crossover of tilt and translation otolith-mediated responses. We are testing this hypothesis by exposing subjects to various combinations of tilt and translation motion profiles over the frequency range from 0.1 Hz to 0.6 Hz. Changes in eye movement and perceptual tilt responses are determined by comparing pre- and post-adaptation runs performed in darkness. During first phase of this grant, we have examined adaptive changes using a ‘vision aligned’ paradigm with JSC’s Preflight Adaptation Training laboratory’s Tilt-Translation Device (TTD). This device was designed to recreate post-flight orientation disturbances by exposing subjects to matching tilt self motion with conflicting visual surround translation. While linear vection is robust during the vision aligned paradigm at 0.1 Hz, the post-adaptive changes are relatively small as predicted at these lower stimulus frequencies. We also conducted control studies for the simultaneous measurement of tilt and translation motion perception using constant velocity Off-Vertical Axis Rotation. Perceived motion was evaluated using verbal reports, a multi-axis joystick, and a simple push-button task indicating nose-up orientation. These studies are important to refine methodology to be used in subsequent adaptation experiments planned for the coming year. More importantly, these studies emphasize differences in the neural processing to distinguish tilt and translation linear acceleration stimuli between eye movements and motion perception.

Our second specific aim is to examine changes in control errors during a closed-loop nulling task before and after tilt-translation adaptation. We predict the ability to control tilt orientation will be compromised following tilt-translation adaptation, with increased control errors corresponding to changes in self-motion perception. During this past year, we reported results of control nulling experiments during roll-tilt step and pseudorandom profiles. This experiment also allowed us to initiate our third specific aim to evaluate how a tactile prosthesis might improve control performance. A simple 4 electromechanical tactor system was developed that provided 6 threshold levels of orientation information. We also examined the influence of vibrotactile feedback during computerized posturography. A significant reduction in RMS error (p<0.05) was observed using this simple tactile prosthesis, both during manual and balance control tasks. These results are promising in that a fairly simple device with as few as 4 tactors may prove useful to significantly improve landing performance. Both studies demonstrate how a tactile prosthesis can be optimized with feed-forward projections using velocity information.

The major effort in the first phase of the project was to design and develop a device to incorporate the ‘GIF aligned’ paradigm in which the chair will tilt within an enclosure that will simultaneously translate so that the resultant gravitoinertial force (GIF) vector remains aligned with the longitudinal body axis. This paradigm will result in a mismatch in which the canals and vision signal tilt while the otoliths do not. The Naval Aerospace Medical Research Laboratory in Pensacola has designed an air bearing track with dual ironless linear motors to provide the translational motion. A dual-wheel friction drive provides tilt chair motion up to 45 deg from vertical inside an 8 feet cube enclosure. During this next year, this device will be used to examine the effects of stimulus frequency on adaptive changes in otolith ocular reflexes, motion perception and closed-loop nulling performance. We will also continue to refine the simple tactile prosthesis, optimizing feed-forward information from velocity to improve control performance. The results of this study will contribute to the refinement of the tactile prosthesis to improve spatial orientation and navigation on different acceleration platforms, including landing systems used for return to Earth after long duration space travel or landing systems used during space exploration missions.

Research Impact/Earth Benefits: This project will provide insight into adaptive mechanisms of otolith function, in particular as they relate to one’s perception of motion and gaze stabilization reflexes. The results of this study will be relevant therefore to vestibular pathophysiology, and understanding compensatory processes following loss or disruption of otolith function in clinical applications. The closed-loop nulling tasks employed by our experiment team will provide a new means of addressing the functional implications of vestibular loss, for example, characterizing risks associated with civilian piloting or automobile driving following vestibular loss. Finally, the development of simple tactile displays will be applicable to balance prosthesis applications for vestibular loss patients and the elderly to mitigate risks due to falling or loss of orientation.

Task Progress & Bibliography Information FY2006 
Task Progress: In support of Specific Aim 1, we completed a study using the ‘vision aligned’ paradigm with NASA’s Tilt-Translation Device. The results emphasize differences in the neural processing to distinguish tilt and translation linear acceleration stimuli between eye movements and motion perception. The results are also consistent with our first hypothesis in that post-adaptive changes are relatively small at lower stimulus frequencies. This study led to one scientific presentation, and a manuscript that is in preparation.

Control studies were conducted to evaluate the simultaneous measurement of tilt and translation motion perception using constant velocity Off-Vertical Axis Rotation. Perceived motion was evaluated using verbal reports, a multi-axis joystick, and a simple push-button task indicating nose-up orientation. These studies are important to refine methodology to be used in subsequent adaptation experiments planned for the coming year. These studies lead to one submitted manuscript, and another in preparation.

In support of Specific Aim 2, results of the roll-tilt nulling experiments completed in year 1 were summarized and presented at two scientific conferences. In support of Specific Aim 3, this study demonstrated how feed-forward information from velocity improved control performance. Also in support of Specific Aim 3, the results of a tactor study during computerized posturography were summarized and presented at another conference. This study was important to expand the application of the tactor system to balance disruption following space flight. Two manuscripts are in preparation from these tactor studies.

The Naval Aerospace Medical Research Laboratory (NAMRL) Engineering Services in Pensacola has completed the device to provide the ‘GIF aligned (gravitoinertial force) paradigm. The progress on this development was delayed due to servo problems with the linear track. Both encoder and drive systems were replaced for the linear track to resolve this issue, and now the device will be operational for the initial studies at the beginning of the next project year. Due to the reduced funding, the initial studies will be conducted at Pensacola to facilitate any modifications needed prior to its relocation to NASA.

Bibliography Type: Description: (Last Updated: 10/25/2021)  Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Wood SJ, Rupert AH. "Effects of vibrotactile feedback on roll-tilt control performance." 77th Meeting of the Aerospace Medical Association, Orlando, FL, May 2006.

Aviat Space Environ Med. 2006 Mar;77(3):350-1. , Mar-2006

Abstracts for Journals and Proceedings Wood SJ, Black FO, Paloski WH, Rupert AH. "Influence of vibrotactile feedback on controlling upright stance during postural perturbations." Meeting of the Association for Research in Otolaryngology, Mt. Royal, NJ, 2006 February.

Assoc Res Otolaryngol Abstracts 2006 Feb;2006:1338. , Feb-2006

Articles in Peer-reviewed Journals Wood SJ, Reschke MP, Clement G. "Tilt and translation motion perception during Off-Vertical Axis Rotation." Experimental Brain Research. Submitted for Publication, July 2006. , Jul-2006
Project Title:  Sensorimotor Adaptation Following Exposure to Ambiguous Inertial Motion Cues Reduce
Fiscal Year: FY 2005 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 09/01/2004  
End Date: 08/31/2008  
Task Last Updated: 11/02/2005 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wood, Scott J. Ph.D. / NASA Johnson Space Center 
Address:  2101 NASA Parkway 
Mail code SD2 
Houston , TX 77058 
Email: scott.j.wood@nasa.gov 
Phone: (281) 483-6329  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments: NOTE: PI returned to NASA JSC in January 2017. PI was at Azusa Pacific University from August 2013 – January 2017; prior to August 2013, PI was at NASA JSC. 
Co-Investigator(s)
Affiliation: 
Harm, Deborah  NASA JSC 
Clement, Gilles  Centre National de la Recherche Scientifique 
Rupert, Angus  Naval Aerospace Medical Research Laboratory 
Project Information: Grant/Contract No. NCC 9-58-NA00405 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2003 Biomedical Research & Countermeasures 03-OBPR-04 
Grant/Contract No.: NCC 9-58-NA00405 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Task Description: The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Our general hypothesis is that the central nervous system utilizes both multi-sensory integration and frequency segregation as neural strategies to resolve the ambiguity of tilt and translation stimuli. Movement in an altered gravity environment, such as weightlessness without a stable gravity reference, results in new patterns of sensory cues. For example, the semicircular canals, vision and neck proprioception provide information about head tilt on orbit without the normal otolith head-tilt position that is omnipresent on Earth. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth’s gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of disorientation and tilt-translation disturbances reported by crewmembers during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during passive tilt and translation motion paradigms. Our first specific aim is to examine the effects of stimulus frequency and different patterns of inertial sensory cues on adaptive changes in eye movements and motion perception during combined tilt and translation motion profiles. Our first hypothesis is that adaptation of otolith-mediated eye movement and perceptual responses will be greatest in the mid-frequency range where there is a crossover of tilt and translation otolith-mediated responses. We are testing this hypothesis by exposing subjects to various combinations of tilt and translation motion profiles over the frequency range from 0.1 Hz to 0.6 Hz. Changes in eye movement and perceptual tilt responses are determined by comparing pre- and post-adaptation runs performed in darkness. The tilt and translation profiles are restricted to one plane at a time to compare adaptation when using either pitch tilt with fore-aft translation or roll tilt with lateral translation. During this first year, we implemented the ‘vision aligned’ paradigm using the JSC’s Preflight Adaptation Training laboratory’s Tilt-Translation Device (TTD). Using this device, tilt chair motion is coupled with translation visual scene motion aligned with the horizontal head axis, resulting in a visual-vestibular mismatch in which both canals and otoliths signal tilt while vision does not. Although the dynamic response of this device has limited measurements to <0.2 Hz, we have begun a series of pilot experiments (N=12, 6M, 6F) designed to examine the most effective phase relationships between tilt chair and translational scene motion. Preliminary results indicate that while linear vection is robust during the vision aligned paradigm at 0.1 Hz, the post-adaptative changes are relatively small as predicted at these lower stimulus frequencies. The major effort in the first project year was to design and develop a device to incorporate the ‘GIF aligned’ paradigm in which the chair will tilt within an enclosure that will simultaneously translate so that the resultant gravitoinertial force (GIF) vector remains aligned with the longitudinal body axis. This paradigm will result in a mismatch in which the canals and vision signal tilt while the otoliths do not. The Naval Aerospace Medical Research Laboratory (NAMRL) Engineering Services in Pensacola has designed an air bearing track with dual ironless linear motors to provide the translational motion. A dual-wheel friction drive provides tilt chair motion up to 45 deg from vertical inside an 8 feet cube enclosure. In addition to elucidating physiological mechanisms for re-entry disturbances, the adaptation paradigms utilized for our first specific aim also provide a ground-based model for evaluating the adverse operational implications of tilt-translation adaptation. Our second specific aim is to employ a closed-loop nulling task in which subjects will be tasked to use a joystick to null out tilt motion disturbances with or without concomitant translation motion. We predict the ability to control tilt orientation will be compromised following tilt-translation adaptation, with increased control errors corresponding to changes in self-motion perception. During this first year, we performed nulling experiments (N=14, 7M, 7F) during roll-tilt step (up to 45 deg) and pseudorandom profiles (0.01, 0.15, 0.3 & 0.6 Hz). This experiment also allowed us to initiate our third specific aim to evaluate how a tactile prosthesis might improve control performance. A simple 4 electromechanical tactor system was developed that provided 6 threshold levels of orientation information. A significant reduction in RMS error (p<0.05) was observed using this simple tactile prosthesis. These results are promising in that a fairly simple device with as few as 4 tactors may prove useful to significantly improve landing performance. During the next project year, we expect to complete the new linear track device in Pensacola, and continue Specific Aims 1 & 2 to examine the effects of stimulus frequency on adaptive changes in otolith ocular reflexes, motion perception and closed-loop nulling performance. We will also continue to refine the simple tactile prosthesis, optimizing feed-forward information from velocity to improve control performance. The results of this study will contribute to the refinement of the tactile prosthesis to improve spatial orientation and navigation on different acceleration platforms, including landing systems used for return to Earth after long duration space travel or landing systems used during space exploration missions.

Research Impact/Earth Benefits: This project will provide insight into adaptive mechanisms of otolith function, in particular as they relate to one’s perception of motion and gaze stabilization reflexes. The results of this study will be relevant therefore to vestibular pathophysiology, and understanding compensatory processes following loss or disruption of otolith function in clinical applications. The closed-loop nulling tasks employed by our experiment team will provide a new means of addressing the functional implications of vestibular loss, for example, characterizing risks associated with civilian piloting or automobile driving following vestibular loss. Finally, the development of simple tactile displays will be applicable to balance prosthesis applications for vestibular loss patients and the elderly to mitigate risks due to falling or loss of orientation.

Task Progress & Bibliography Information FY2005 
Task Progress: 1. In support of Specific Aim 1, pilot studies have been initiated with 12 subjects (6M, 6F) to examine the most effective phase relationships between tilt chair and translational scene motion during the ‘vision aligned’ paradigm using the JSC’s Preflight Adaptation Training laboratory’s Tilt-Translation Device (TTD). Note that these studies were delayed for ~4 months due to facility lockout. 2. The Naval Aerospace Medical Research Laboratory (NAMRL) Engineering Services in Pensacola has designed a new device to provide the ‘GIF aligned (gravitoinertial force) paradigm. This device includes an air bearing track with dual ironless linear motors to provide the translational motion. A dual-wheel friction drive provides tilt chair motion up to 45 deg from vertical inside an 8 feet cube enclosure. The initial progress on this development was delayed due to facility shutdown following Hurricane Ivan. This device should be completed during the first half of project year 2. 3. In support of Specific Aim 2, roll-tilt nulling experiments were completed in 14 subjects (7M, 7F) during step (up to 45 deg) and pseudorandom profiles (0.01, 0.15, 0.3 & 0.6 Hz). 4. In support of Specific Aim 3, a simple electromechanical tactor system using only 4 tactors was developed that provided 6 threshold levels of orientation information. During the next year, we will continue to refine this tactile prosthesis, optimizing feed-forward information from velocity to improve control performance.

Bibliography Type: Description: (Last Updated: 10/25/2021)  Show Cumulative Bibliography Listing
 
Presentation Wood, S. J., G. R. Clement, D. L. Harm, A. H. Rupert, F. E. Guedry, and M. F. Reschke "Sensorimotor adaptation following exposure to ambiguous inertial motion cues" N/A

Jan-2005

Project Title:  Sensorimotor adaptation following exposure to ambiguous inertial motion cues Reduce
Fiscal Year: FY 2004 
Division: Human Research 
Research Discipline/Element:
HRP HHC:Human Health Countermeasures
Start Date: 09/01/2004  
End Date: 08/31/2008  
Task Last Updated: 03/30/2006 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wood, Scott J. Ph.D. / NASA Johnson Space Center 
Address:  2101 NASA Parkway 
Mail code SD2 
Houston , TX 77058 
Email: scott.j.wood@nasa.gov 
Phone: (281) 483-6329  
Congressional District: 36 
Web:  
Organization Type: NASA CENTER 
Organization Name: NASA Johnson Space Center 
Joint Agency:  
Comments: NOTE: PI returned to NASA JSC in January 2017. PI was at Azusa Pacific University from August 2013 – January 2017; prior to August 2013, PI was at NASA JSC. 
Project Information: Grant/Contract No. NCC 9-58-NA00405 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2003 Biomedical Research & Countermeasures 03-OBPR-04 
Grant/Contract No.: NCC 9-58-NA00405 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:  
No. of PhD Candidates:  
No. of Master's Candidates:  
No. of Bachelor's Candidates:  
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:  
Human Research Program Elements: (1) HHC:Human Health Countermeasures
Human Research Program Risks: (1) Sensorimotor:Risk of Altered Sensorimotor/Vestibular Function Impacting Critical Mission Tasks (Revised as of IRP Rev M)
Human Research Program Gaps: (1) SM06:Can a seated manual/visual performance assessment after long-duration spaceflight be completed? (OBSOLETE - Merged with SM12 to create SM6.1, per IRP Rev F)
Task Description: The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Previous studies suggest that both frequency segregation and multi-sensory integration are complementary strategies used for discriminating linear accelerations arising from tilt and translation head motion. Adaptive changes during space flight in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth’s gravity. We hypothesize that multi-sensory integration will be adaptively optimized in altered gravity environments based on the dynamics of other sensory information available, with greater changes in otolith-mediated responses in the mid-frequency range where there is a crossover of tilt and translational otolith-mediated responses. The first phase of our experiments is designed to elucidate physiological mechanisms for re-entry disturbances, and to develop a ground-based adaptation model for evaluating adverse operational implications of tilt-translation adaptation. The first specific aim of this proposal will be to examine the effects of stimulus frequency and different patterns of inertial sensory cues on adaptive changes in eye movements and motion perception during combined tilt and translational motion profiles. For our second specific aim, we will employ a closed-loop nulling task in which subjects will be tasked to use a joystick to null out tilt motion disturbances with or without concomitant translational motion. Our final specific aim is to evaluate how a tactile prosthesis can be used to improve control performance. The results of this study will contribute to refining the ability of the tactile prosthesis to improve spatial orientation and navigation and serve as a countermeasure for tilt-translational disturbances during and following G-level changes.

Research Impact/Earth Benefits:

Task Progress & Bibliography Information FY2004 
Task Progress: New grant in FY2004; no progress report this period.

Bibliography Type: Description: (Last Updated: 10/25/2021)  Show Cumulative Bibliography Listing
 
 None in FY 2004