Temporal Modulation of Transcutaneous Electrical Nerve Stimulation Influences Sensory Perception

The incorporation of sensory feedback in prosthetics can lead to a range of benefits, such as improved hand control, increased prosthesis embodiment, and the reduction of phantom limb pain. However, the creation of reliable sensory feedback is complicated by the temporal modulation of the nervous system. Sensory fibres in the hand are primed to react to changing conditions, firing when discrete mechanical events occur. In this study, we investigate the minimal possible stimulation needed to distinguish different sensory patterns that can be used to indicate events. We presented a two-alternative forced-choice task of transcutaneous electrical nerve stimuli to 10 participants. The results showed that different stimuli can be distinguished when double pulses have an inter-stimulus-interval of 10 ms. Additionally, providing a pause of at least 350 ms between stimuli increases the discrimination of the perception. These results suggest that humans can distinguish different patterns of transcutaneous electrical nerve stimulation with as little as two stimuli, illustrating the possibility of providing event-related stimulation.