three topics are funded primarily through the Gravitational Biology and Ecology (GB&E)1 program and have been included in this review. The current NASA biomedical research program is considered in light of all nine subdiscipline areas. Research projects that have a primary focus on the interactions of the vestibular system with the cardiovascular or musculoskeletal systems are not covered here.
Altogether in FY 1999, NASA funded 39 projects relevant to sensorimotor integration; these are classified in Table 2.1 according to the nine subdiscipline areas described above. Funding for this research was contributed by three NASA programs (Biomedical Research and Countermeasures, Advanced Human Support Technologies, and Gravitational Biology and Ecology), the National Space Biomedical Research Institute (NSBRI), and a new cooperative National Institutes of Health (NIH)-NSBRI program. Within the Biomedical Research and Countermeasures (BR&C) program, sensorimotor integration research is included in three disciplines: (1) behavior and performance; (2) physiology: neuro-science; and (3) operational and clinical. The 12 projects funded through the GB&E program are concerned with the basic mechanisms underlying vestibular function or the effects of gravity on vestibular development. In FY 1999, the total funding for research on sensorimotor integration was approximately $7.8 million, which places this work in the top quarter of NASA’s Biomedical Research (NASA, 1999). In FY 1998, the funding level for sensorimotor integration research was approximately $6 million, with 40 projects being supported. The increase in funding in FY 1999 reflected the new cooperative NIH-NSBRI program for the support of vestibular research, which had a funding level of $1.4 million, 80 percent of which was provided by the National Institute of Deafness and Communicative Disorders.
Studies on sensorimotor integration are carried out in all four components of the NASA life sciences research enterprise, including the laboratories at Johnson Space Center (JSC), Ames Research Center (ARC), and numerous universities funded either through the NASA Research Announcement (NRA) mechanism or through the NSBRI. In addition to conducting intramural research, scientists at JSC and ARC routinely collaborate on university-based research programs. JSC scientists have also been involved in setting up laboratories in Star City, Russia, to investigate postural control, locomotion, and visual target acquisition after long-duration spaceflight. The Neurological Function Section at JSC is focused on human studies of posture and locomotion, vestibulo-ocular reflex and oculomotor control, and visual adaptation and space motion sickness. Specialized facilities exist for pre- and postflight studies of visuospatial adaptation and postural stability. At ARC, both human and animal studies are conducted on spatial orientation, vestibulo-ocular reflexes and oculomotor control, and space motion sickness. ARC has facilities for centrifuge studies on humans to determine the time course of adaptation to different g-levels and the effects of altered gravity on human behavior and performance. The center also has several facilities for testing the responses of the vestibular system to linear and angular acceleration in small animals and in human subjects.
There are three major research projects supported entirely by the NSBRI in the area of neuro-vestibular adaptation, two of which have a coinvestigator at JSC. These are focused on adaptation of vestibular reflexes to different gravitoinertial force conditions; spatial orientation and mobility, in particular visually induced tilt and reorientation illusions; and eye, head, and body movements during locomotion and their stability in a range of environments. A fourth project on neurovestibular adaptation