“EEG signal quality and noise characteristics in spaceflight”
Patrique Fiedler*, Jens Haueisen, Ana M. Cebolla Alvarez, Guy Cheron, Pablo Cuesta, Fernando Maestú, and Michael Funke
* Institute of Biomedical Engineering and Informatics, TU Ilmenau, Ilmenau, Germany
patrique.fiedler@tu-ilmenau.de

Long-duration space missions critically depend on the cognitive performance of the crew. The physical effects of spaceflight are known for decades. Adverse cognitive effects have been reported (Takács et al., 2021), requiring further investigation, and close monitoring. Due to mobility, high spatial and temporal resolution, Electroencephalography (EEG) is a suitable modality for neuroscientific in-flight real-time brain monitoring. However, to date, no systematic investigations on signal quality and interferences in spaceflight environments have been reported.  
We compare the signal characteristics of spaceflight and on-earth EEG recordings to identify eventual shortcomings in signal quality. We analyse previously recorded and published data during spaceflight (Cebolla et al., 2016), comparing the signal characteristics to recordings performed on earth using the same device, and EEG systems with active shielding noise reduction (asalab and eego systems, ANT Neuro). We furthermore include both gel-based and dry electrode data in the comparison. 
Our results show that no increased noise level is evident for the EEG recordings during spaceflight, compared to recordings on earth. The absence of powerline interference in the inflight recordings may support simplified analysis. Moreover, the spectral power of the inflight recordings is in the order of magnitude of the on-earth recordings performed using active shielding noise reduction measures. 
We conclude that EEG recordings during spaceflight are possible without considerable environmental noise interference differences and may further profit from the use of easy to apply, gel-free dry electrode technology.