Changes of EEG beta band power and functional connectivity during spaceflight: a retrospective study

Figures

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  Fig. 1. Changes in beta band relative power (eyes-closed) between flight conditions. (a) Statistical comparison between conditions. The bar graph depicts the mean ± SD of the beta band power for each flight condition (*p < 0.05, **p < 0.01, ***p < 0.001). (b–d) Brain figures in the dashed boxes represent the areas with higher statistical power changes in the beta band comparing areas between (b) pre-flight versus in-flight conditions, (c) post-flight versus in-flight conditions, (d) pre-flight versus post-flight conditions. The colorbar is displayed as a family-wise corrected significance level of q value > 5, corresponding with a minimum p value of 0.05. The q statistic value was obtained from the results of the post-hoc Tuckey test of the multiple comparison corrections. Thus, the darker the blue color represents brain regions with higher statistical power. The five subjects are mentioned by the respective code letter under each bar. Brain figures were generated using ‘Image Processing Toolbox’ and ‘Medical Imaging Toolbox’ from Matlab R2023b (version 23.2, https://www.mathworks.com/products/matlab.html).

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  Fig. 2. Changes in beta band relative power (eyes-open) between flight conditions. (a) Statistical comparison between conditions. The bar graph depicts the mean ± SD of the beta band power for each flight condition (*p < 0.05, **p < 0.01, ***p < 0.001). (b–d) Brain figures in the dashed boxes represent the areas with higher statistical power changes in the beta band comparing areas between (b) pre-flight versus in-flight conditions, (c) post-flight versus in-flight conditions, (d) pre-flight versus post-flight conditions. The colorbar is displayed as a family-wise corrected significance level of q value > 5, corresponding with a minimum p value of 0.05. The q statistic value was obtained from the results of the post-hoc Tuckey test of the multiple comparison corrections. Thus, the darker the blue color represents brain regions with higher statistical power. The five subjects are mentioned by the respective code letter under each bar. Brain figures were generated using ‘Image Processing Toolbox’ and ‘Medical Imaging Toolbox’ from Matlab R2023b (version 23.2, https://www.mathworks.com/products/matlab.html).

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  Fig. 3. Differences between eyes-closed and eyes-open in beta band relative power between flight conditions. (a) Comparison between eyes-closed and eyes-open in the pre-flight condition (p = 0.1184). (b) Comparison between eyes-closed and eyes-open in the in-flight condition (p = 0.3495). (c) Comparison between eyes-closed and eyes-open in the post-flight condition (p < 0.0001). Bar graphs depict the mean ± SD of the beta band power for each flight condition per subject. The dark blue in a bar indicates the eyes-closed condition, whereas the light blue bar indicates eyes-open condition. The five subjects are mentioned by their respective code letter under each bar. (*p < 0.05, **p < 0.01, ***p < 0.001).

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  Fig. 4. Changes in beta FC strength (eyes-closed) between flight conditions. (a) Statistical comparison between conditions. The bar graph depicts the mean ± SD of the beta band FC strength for each flight condition (*p < 0.05, **p < 0.01, ***p < 0.001). (b–d) Brain figures in the dashed boxes represent the areas with higher statistical FC changes in the beta band comparing areas between (b) pre-flight versus in-flight conditions, (c) post-flight versus in-flight conditions, (d) pre-flight versus post-flight conditions. The colorbar is displayed as a family-wise corrected significance level of q value > 5, corresponding with a minimum p value of 0.05. The q statistic value was obtained from the results of the post-hoc Tuckey test of the multiple comparison corrections. Thus, the darker the red color represents brain regions with higher statistical power. The five subjects are mentioned by the respective code letter under each bar. Brain figures were generated using ‘Image Processing Toolbox’ and ‘Medical Imaging Toolbox’ from Matlab R2023b (version 23.2, https://www.mathworks.com/products/matlab.html).

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  Fig. 5. Changes in beta FC strength (eyes-open) between flight conditions. (a) Statistical comparison between conditions. The bar graph depicts the mean ± SD of the beta band FC strength for each flight condition (*p < 0.05, **p < 0.01, ***p < 0.001). (b–d) Brain figures in the dashed boxes represent the areas with higher statistical FC changes in the beta band comparing areas between (b) pre-flight versus in-flight conditions, (c) post-flight versus in-flight conditions, (d) pre-flight versus post-flight conditions. The colorbar is displayed as a family-wise corrected significance level of q value > 5, corresponding with a minimum p value of 0.05. The q statistic value was obtained from the results of the post-hoc Tuckey test of the multiple comparison corrections. Thus, the darker the red color represents brain regions with higher statistical power. The five subjects are mentioned by the respective code letter under each bar. Brain figures were generated using ‘Image Processing Toolbox’ and ‘Medical Imaging Toolbox’ from Matlab R2023b (version 23.2, https://www.mathworks.com/products/matlab.html).

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  Fig. 6. Differences between eyes-closed and eyes-open in beta band FC strength between flight conditions. (a) Comparison between eyes-closed and eyes-open in the pre-flight condition (p < 0.05). (b) Comparison between eyes-closed and eyes-open in the in-flight condition (p < 0.05). (c) Comparison between eyes-closed and eyes-open in the post-flight condition (p < 0.001). Bar graphs depict the mean ± SD of the beta band power for each flight condition per subject. The dark blue in a bar indicates the eyes-closed condition, whereas the light blue bar indicates eyes-open condition. The five subjects are mentioned by their respective code letter under each bar (*p < 0.05, **p < 0.01, ***p < 0.001).