Temporal patterns in electrical nerve stimulation: burst gap code shapes tactile frequency perception

Published: March 29, 2021, 1:03 a.m.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.04.10.033241v1?rss=1 Authors: Ng, K. K. W., Olausson, C., Vickery, R. M., Birznieks, I. Abstract: We have described a novel temporal encoding mechanism in the somatosensory system, where tactile pulses grouped into periodic bursts create a perceived frequency based on the duration of the silent gap between bursts, rather than the mean rate or the periodicity. This coding strategy may offer new opportunities for transmitting information to the brain using various sensory neural prostheses and brain-machine interfaces. However, it was not known whether the same coding mechanisms apply when electrical, rather than mechanical, stimulation is used. Here, we demonstrate that the predictions of the burst gap coding model for frequency perception apply to burst stimuli delivered with electrical pulses, re-emphasising the importance of the temporal structure of spike patterns in neural processing and perception of tactile stimuli. Reciprocally, the electrical stimulation data confirm that the results observed with mechanical stimulation do indeed depend on neural processing mechanisms in the central nervous system and are not due to mechanical effects in the skin or afferent population activation patterns. Our results suggest that spike intervals contribute to perceived frequency with perceptual weights that depend on their duration, and that a generalised frequency processing system would explain the constancy of vibrotactile frequency perception across different receptor types. Copy rights belong to original authors. Visit the link for more info