biology and biotechnology

SPATIAL REORIENTATION FOLLOWING SPACEFLIGHT, DETAILED SUPPLEMENTARY OBJECTIVE 635

(SPATIAL, DSO 635)

Research Area: Human Research: Nervous and Vestibular Systems

Expedition(s): ● William H. Paloski, PhD, NASA’s Johnson Space Center,

Houston, Texas

RESEARCH OBJECTIVES

The Spatial Reorientation Following Spaceflight (Spatial)

study examines adaptive changes in spatial processing for

balance control following short-duration spaceflight.

The first specific aim of this study was to examine

adaptive changes in spatial processing for balance control

following spaceflight by incorporating static and dynamic

tilts that disassociate head and gravity reference frames.

Impairments to sensorimotor (sensory and motor)

coordination of body segments following spaceflight are

more pronounced after landing when the head is actively

tilted with respect to the trunk. This suggests that central

vestibular processing shifts from a gravitational frame of

reference (aligned with gravity vector) to a head frame of

reference (aligned to head position) in microgravity. A

major effect of such changes is a significant postural

instability. Decreases in functional performance may still

be underestimated when head and gravity reference

frames remained aligned. A second aim of this study was

to examine the feasibility of altering the re-adaptation

process by providing discordant visual-vestibular

somatosensory (sensory system perception) stimuli using

short-radius pitch centrifugation. Previous observations

suggested that conflicting sensory stimuli caused by an

unusual motion environment disrupted spatial orientation

and balance control in a returning crew member possibly by triggering a change in the central

vestibular system (inner ear, eyes, and the central nervous system).

EARTH BENEFITS

A better understanding of the characteristics of sensorimotor recovery from short-duration

spaceflights will help in understanding the mechanisms related to the adaptation of balance

control. The findings are also expected to demonstrate the feasibility of triggering state changes

between sensorimotor control sets using a centrifuge device. The results will also be of use to

clinical and military researchers interested in adaptive changes in spatial processing to altered

gravitational environments, and the fragility of the sensorimotor adaptive processes. These

findings will improve the understanding of the functional risks to crew members after

A view of the posturography (the study of
posture and its effects on health) system
located in the JSC Neuroscience
Laboratories. As a part of the medical
requirement test battery, posturography
is currently being performed on returning
short and long duration crewmembers to
assist in determining their return-to-duty
status. ESA image.