Sungshin Kima, Thierri Calliera, Gregg A. Tabotb, Robert A. Gauntc, Francesco V. Tenored, and Sliman J. Bensmaiaa,b,1
aDepartment of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637;
bCommittee on Computational Neuroscience, University of Chicago, Chicago, IL 60637;
cDepartment of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213;
dResearch and Exploratory Development Department, Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723
Abstract
Intracortical microstimulation (ICMS) is a powerful tool to investigate the functional role of neural circuits and may provide a means to restore sensation for patients for whom peripheral stimulation is not an option. In a series of psychophysical experiments with nonhuman primates, we investigate how stimulation parameters affect behavioral sensitivity to ICMS. Specifically, we deliver ICMS to primary somatosensory cortex through chronically implanted electrode arrays across a wide range of stimulation regimes. First, we investigate how the detectability of ICMS depends on stimulation parameters, including pulse width, frequency, amplitude, and pulse train duration. Then, we characterize the degree to which ICMS pulse trains that differ in amplitude lead to discriminable percepts across the range of perceptible and safe amplitudes. We also investigate how discriminability of pulse amplitude is modulated by other stimulation parameters-namely, frequency and duration. Perceptual judgments obtained across these various conditions will inform the design of stimulation regimes for neuroscience and neuroengineering applications.
neuroprosthetics, psychophysics, brain-machine interfaces, threshold, just noticeable difference
1To whom correspondence should be addressed.
Author contributions: R.A.G., F.V.T., and S.J.B. designed research; T.C. performed research; S.K. and G.A.T. analyzed data; and S.K., T.C., G.A.T., R.A.G., F.V.T., and S.J.B. wrote the paper.