The investigators hypothesize that dexmedetomidine produces fewer changes as compared to propofol, and that those changes are consistent and recognizable when compared to activity in patients not exposed to any sedation. Typification of those changes would in the future allow for patients to undergo this surgery comfortably while not compromising the quality of the recording and of the final clinical outcome. The principal variable analyzed is the signal's power in each of the frequency bands, absolute and relative. The analysis will include usual clinical methods such as rapid Fourier transform (FFT) and window fast Fourier transform (WFFT), wavelet analysis, Gabor, and coherence.