RT Journal Article SR Electronic T1 Neural Coding of the Location and Direction of a Moving Object by a Spatially Distributed Population of Mechanoreceptors JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 9556 OP 9566 DO 10.1523/JNEUROSCI.22-21-09556.2002 VO 22 IS 21 A1 Robert M. Friedman A1 Partap S. Khalsa A1 Kenneth W. Greenquist A1 Robert H. LaMotte YR 2002 UL http://www.jneurosci.org/content/22/21/9556.abstract AB A neural code for the location and direction of an object moving over the fingerpad was constructed from the responses of a population of rapidly adapting type I (RAs) and slowly adapting type I (SAs) mechanoreceptive nerve fibers. The object was either a sphere with a radius of 5 mm or a toroid with radii of 5 mm on the major axis and either 1 or 3 mm on the minor axis. The object was stroked under constant velocity and contact force along eight different linear trajectories. The spatial locations of the centers of activity of the population responses (PLs) were determined from nonsimultaneously recorded responses of 99 RAs and 97 SAs with receptive fields spatially distributed over the fingerpad of the anesthetized monkey. The PL at each moment during each stroke was used as a neural code of object location. The angle between the direction of the trajectory of the PL and mediolateral axis was used to represent the direction of motion of the object. The location of contact between the object and skin was better represented in SA than in RA PLs, regardless of stroke direction or object curvature. The PL representation of stroke direction was linearly related to the actual direction of the object for both RAs and SAs but was less variable for SAs than for RAs. Both the SA and RA populations coded spatial position and direction of motion at acuities similar to those obtained in psychophysical studies in humans.