Extended Data Fig. 1: Spectral analysis of vibrations stimulus measured with a laser doppler vibrometer.
From: Emergence of a brainstem somatosensory tonotopic map for substrate vibration
a, Example of a displacement measured by the laser doppler vibrometer of a single 400-Hz vibration. The middle-half interval of spectral analysis was highlighted in red. b, Amplitude spectrum of the displacement produced by 10 trials of 400-Hz stimuli indicates that the physical vibration consisted of a single frequency component (nearly a pure sinusoid). Components apparent at the distant frequencies were highly attenuated relative to the stimulation frequency, similar to the background noise. c, Amplitude spectra were obtained for stimuli at all tested frequencies and four representative amplitudes from two different piezo actuators.
