Vibrotactile stimulus duration threshold for perception of pulse to vibration transition Scientific Reports Application of biomimetic tongue substrate to investigate the role of friction and vibration in sensory texture perception ScienceDirect Application of biomimetic tongue substrate to investigate the role of friction and vibration in sensory texture perception ScienceDirect The vagus nerve is a primary carrier of information describing the state of the body to the brain, and transmitting information from the brain back to the body. It's a feedback mechanism PDF] Mechanical Vibrations by J. P. Den Hartog 9780486131856