## 3 Results
\begin{table}
\begin{tabular}{c c c c c c} \hline
**EEG Indices** & **Site** & **Before Inhalation (uV\({}^{2}\))** & **During Inhalation (uV\({}^{2}\))** & **\(t\)-Test** & **\(p\) Value \({}^{*}\)** \\ \hline AHB & Cp6 & 14.0263 \(\pm\) 9.7133 & 10.5390 \(\pm\) 9.3952 & 2.636 & 0.027 \\ \hline ALB & Cp6 & 5.6537 \(\pm\) 3.3128 & 3.9980 \(\pm\) 3.1012 & 2.372 & 0.042 \\ \hline  & T8 & 0.5053 \(\pm\) 0.1354 & 0.3485 \(\pm\) 0.1156 & 3.304 & 0.009 \\ RST & Cp6 & 0.4796 \(\pm\) 0.1091 & 0.2978 \(\pm\) 0.0877 & 2.390 & 0.041 \\  & P3 & 0.3233 \(\pm\) 0.0912 & 0.2372 \(\pm\) 0.0873 & 2.361 & 0.043 \\ \hline  & T4 & 0.4222 \(\pm\) 0.0933 & 0.3111 \(\pm\) 0.0890 & 2.364 & 0.042 \\ RMT & P3 & 0.3821 \(\pm\) 0.0825 & 0.2468 \(\pm\) 0.0675 & 2.453 & 0.037 \\ \hline  & P3 & 0.7054 \(\pm\) 0.1484 & 0.4840 \(\pm\) 0.1505 & 2.836 & 0.020 \\ RSMT & Cp2 & 0.8552 \(\pm\) 0.1538 & 0.5914 \(\pm\) 0.1688 & 2.386 & 0.041 \\ \hline  & F4 & 11.7798 \(\pm\) 1.4694 & 10.0464 \(\pm\) 1.5986 & 2.681 & 0.025 \\  & T4 & 11.5295 \(\pm\) 1.1366 & 9.5337 \(\pm\) 1.3479 & 3.302 & 0.009 \\  & P3 & 10.8765 \(\pm\) 0.7135 & 8.8013 \(\pm\) 0.9192 & 3.328 & 0.009 \\  & P4 & 11.3525 \(\pm\) 0.8768 & 9.6497 \(\pm\) 1.3301 & 2.290 & 0.048 \\  & O1 & 12.2498 \(\pm\) 1.5447 & 10.3577 \(\pm\) 1.7093 & 3.198 & 0.011 \\ SEF50 & O2 & 12.1338 \(\pm\) 1.3258 & 10.3088 \(\pm\) 1.6092 & 2.981 & 0.015 \\  & T8 & 15.8264 \(\pm\) 1.5940 & 11.1938 \(\pm\) 1.5220 & 5.191 & 0.001 \\  & Cz & 11.6516 \(\pm\) 1.4254 & 9.7900 \(\pm\) 1.6372 & 2.688 & 0.025 \\  & Cp2 & 11.9202 \(\pm\) 1.4366 & 9.7839 \(\pm\) 1.5728 & 3.500 & 0.007 \\  & Cp6 & 12.3901 \(\pm\) 1.3353 & 10.1624 \(\pm\) 1.5718 & 3.696 & 0.005 \\ \hline  & Fp1 & 32.0923 \(\pm\) 1.8613 & 24.8718 \(\pm\) 3.5291 & 2.685 & 0.025 \\  & Fp2 & 33.0078 \(\pm\) 1.6117 & 24.3164 \(\pm\) 3.2836 & 2.628 & 0.027 \\  & F3 & 27.7039 \(\pm\) 2.1683 & 21.5942 \(\pm\) 2.9508 & 3.007 & 0.015 \\ SEP90 & F4 & 26.8921 \(\pm\) 2.6945 & 22.2107 \(\pm\) 2.9661 & 2.415 & 0.039 \\  & P4 & 27.1973 \(\pm\) 2.3330 & 21.8201 \(\pm\) 2.7859 & 2.956 & 0.016 \\  & T8 & 35.4553 \(\pm\) 2.7690 & 29.2480 \(\pm\) 3.5502 & 3.153 & 0.012 \\  & Cp2 & 28.4241 \(\pm\) 2.8740 & 22.2290 \(\pm\) 2.8799 & 2.846 & 0.019 \\  & T7 & 32.9712 \(\pm\) 2.1259 & 27.1912 \(\pm\) 3.4314 & 2.641 & 0.027 \\ \hline  & Fc1 & 10.4675 \(\pm\) 0.1555 & 10.0952 \(\pm\) 0.1387 & 2.667 & 0.026 \\ ASF & T8 & 10.4492 \(\pm\) 0.1373 & 10.0342 \(\pm\) 0.1520 & 2.449 & 0.037 \\  & Af4 & 10.4187 \(\pm\) 0.1328 & 10.0159 \(\pm\) 0.1606 & 2.490 & 0.034 \\  & Fpz & 10.4187 \(\pm\) 0.1214 & 10.0281 \(\pm\) 0.1651 & 2.331 & 0.045 \\ \hline \end{tabular}  
* AHB, absolute high beta; ALB, absolute low beta; RST, ratio of SMR to theta; RMT, ratio of mid beta to theta; RSMT, ratio of SMR mid beta to theta; SEF50, spectral edge frequency 50%; SEP90, spectral edge frequency 90%; ASEF, spectral edge frequency 50% of alpha. The results are significant changes of absolute and ratio values before and during the inhalation of geosmin with the exclusion of relative values (Out of 25 EEG indices). Significant changes were not observed during the inhalation of geosmin for men. Values are expressed as the mean \(\pm\) standard deviation.
* * Significant difference (\(p<0.05\)), Number of subjects—10.  
\end{table} 
Table 2: Significant changes of EEG power spectra during the inhalation of geosmin in women. observed in 10 and eight regions, respectively. On the other hand, 2-methylisoborneol exhibited changes only in the relative and other ratio values such as alpha, slow alpha, low beta, mid beta, high beta, RST, RMT, RSMT, and SEF90 (Table 3). Among them, RMT values significantly changed in eight regions (O2, F8, Cz, Pz, Af4, Fc2, Cp5, and Cp6). In addition, 2-methylisoborneol odor mainly exhibited changes at Cp5 region for the ratio spectrum values than other regions. Figure 4 illustrates the schematic representation of significant changes of EEG indices during the inhalation of geosmin and 2-methylisoborneol. \begin{table}