Neurocognitive assessment in microgravity: review of tools and benefits of increasing their clinical validity for long duration missions

Abstract

Introduction: Clinical complications are not expected in current space missions; however, for future long-duration missions to the Moon and Mars, a new perspective may be needed – a more clinical approach. Different risks, both environmental, such as radiation, accidents, and biopsychological, including neurological problems, represent potential sources of subsequent neurocognitive deficits. Aims: This study aims to review research studies published to this date in microgravity conditions using existing spaceflight neurocognitive assessment batteries. This study also discusses the different risks of neuropsychological impairment in spaceflight and the potential benefits of increasing the clinical validity of these tools with neurological clinical samples on Earth for future long-duration missions. Method: A PRISMA guidelines-based review of specialized literature on neurocognitive assessment batteries and human spaceflight was performed. Different factors including type of tool or battery used, sample size, mission duration, etc. were included in this review. After the scrutiny of 192 articles, a total of 27 studies were detailed in the review outcome. Results: Results showed that neuropsychological function research target has changed over the years, with working memory and perception studies being predominant in the 80s and 90s while reaction time being more frequent in recent research. We also found a lack of language-related research in microgravity and the predominance of two neurocognitive assessment batteries in microgravity research. Conclusions: With this study, we want to emphasize the importance of increasing the clinical validity of neurocognitive or neuropsychological assessment tools to be used in space, especially in long-duration missions because in this type of mission the risk of suffering a brain injury or neurological condition increases due to multiple factors. Testing these tools with neurological clinical samples and using machine learning, predictive systems may help crews in early detection of potential clinical, neurological, or neurocognitive problems during these long-duration missions to Mars and beyond.