Despite humanity’s decades-long relationship with spaceflight, we still do not know the range of gravity levels (or gravity doses) that sustain normal physiological function. This is a concern because astronauts are required to utilize bimanual coordination, a domain of sensorimotor function and physiology, for numerous operational tasks. Critical tasks involving bimanual coordination, such as landing a spacecraft or piloting a rover, may be required during micro/partial gravity or during rapid G-transitions. Previous investigations have provided evidence of decrements in sensorimotor performance in hypo-gravity and hyper-gravity environments. However, these experiments focused primarily on unimanual control, and there is a lack of research on bimanual coordination performance in altered gravity.
We will use various analogs (i.e., head down tilt (HDT)/head up tilt (HUT), short-radius centrifuge, and parabolic flight) to simulate altered gravity. Subjects will be asked to complete two different bimanual coordination tasks at various G-levels (0 to 1.8 G). The first task will require subjects to coordinate forces produced by their left and right triceps while the second task will involve coordinating elbow flexor-extensor movements. We will then compare performance on these tasks between each gravity level that we test. Additionally, we are interested in looking for any evidence of bimanual coordination adaptation after repeated exposure to altered gravity.
Experiments conducted using the centrifuge and parabolic flight also allow us to study bimanual coordination performance during G-transitions. We will use data from these experiments to determine the relationship between gravity dose and bimanual coordination performance and estimate the range of gravity levels that elicits an “Earth-like” performance. During the parabolic flight experiments, we will also investigate the potential impact of an anti motion sickness drug (Promethazine) on bimanual coordination. Work on this project is being done in collaboration with Dr. Bonnie J. Dunbar’s Aerospace Human Systems Laboratory and Dr. Deanna Kennedy’s Neuromuscular Coordination Lab.