Neurocognitive Changes and Neuroplastic Adaptations in Altered Gravitational Environments

Human adaptation to altered gravitational environments remains a key challenge for space missions and translational biomedicine. The dynamic human brain, responds to microgravity through complex neurophysiological and neuroplastic adaptations. This chapter explores neurocognitive and neuroplastic responses to simulated microgravity using a 20° head-down tilt (HDT) model, a validated analog for spaceflight-induced cephalad fluid shifts. Electrophysiological analyses employing event-related potentials (ERPs), specifically P300 and Contingent Negative Variation (CNV), revealed significant neurocognitive modulation during acute HDT exposure. These findings were corroborated by subjective discomfort and autonomic changes, reflecting the integrated physiological stress of altered hydrostatic gradients. The translational implications extend to clinical rehabilitation, where HDT-induced changes in ERP markers provide valuable analogs for cognitive slowing seen in concussion, depression, and prolonged immobility. By bridging aerospace physiology and clinical neuroscience, this work establishes a foundational framework for understanding gravity-induced neuroplasticity, impacting both astronaut safety and advancements in neurorehabilitation.