The vibro-tactile stimulations experiment to verify the optimal resonance frequency of human's tactile system

Human body can obtain proprioception through the tactile sense. When part of the body is stimulated by tactile vibration at a particular frequency, a periodic electrophysiological brain response is elicited in the EEG activity. This response, called the steady-state somatosensory evoked potentials (SSSEPs), has the same frequency components as the driving tactile stimulus and sometimes also higher harmonics. In this study, based on the characteristics of magnetic steel, we developed a somatosensory tactile actuator which could generate the constant low-frequency stimulus. And in order to verify the optimal resonance frequency of human's tactile system, vibro-tactile stimulations of different frequencies were carried out to different subjects' right index fingers. The experiment results showed that the largest response amplitudes are typically observed for stimulation frequencies near 21 Hz.