From infancy, people possess an innate understanding of how the world functions, allowing them to interact appropriately with their surroundings. This includes the accurate detection of gravity through an internal model of its effects. Previous research has shown that even during space flight, astronauts’ motor responses remain attuned to gravitational acceleration. For example, when asked to catch a ball projected “downward” from the ceiling, astronauts contracted their limb muscles too early, anticipating non-existent gravity effects.
In a recent study published in NPJ Microgravity, astronauts were asked to imagine throwing an imaginary ball toward the ceiling and catching it upon rebound, while imagining it moving under Earth gravity or in weightlessness. Surprisingly, the astronauts were able to implicitly reproduce the 0g conditions on the ground prior to their mission, and their performance improved over time in space. This demonstrates a dissociation between the motor control system and cognitive system, with the former driving automatic responses tuned to Earth’s gravity, while the latter allows for the imagination of 0g movements even on the ground.
Mental imagery can play an important role in training individuals to deal with unique conditions in spaceflight and may serve as a potential countermeasure for sensorimotor and cognitive dysfunctions resulting from spaceflight. Additionally, mental imagery protocols may offer benefits on Earth for brain-injured patients who face similar challenges as astronauts. The study highlights the importance of implicit knowledge and mental imagery in human adaptation to novel environments.