 |
 Previous Article | Next Article 
Journal of Neuroscience, Vol 12, 827-839, Copyright © 1992 by Society for Neuroscience
Responses of human mechanoreceptive afferents to embossed dot arrays scanned across fingerpad skin
JR Phillips, RS Johansson and KO Johnson
University Laboratory of Physiology, Oxford, United Kingdom.
The spatial resolving capacities of the four classes of mechanoreceptive
afferents innervating human fingerpad skin were investigated to determine
which class sets the limit of tactile spatial resolution for scanning
stimuli. The stimulus consisted of an array of embossed dots (0.7 mm
diameter, 0.5 mm high) arranged in a tetragonal pattern with dot spacing
decreasing linearly from 6.4 mm at one end of the array to 0.87 mm at the
other. The pattern was wrapped around a drum and repeatedly scanned across
the receptive field of single afferents by continuously rotating the drum.
Responses to many closely spaced scans were obtained by imposing a lateral
shift of the pattern between each revolution. Impulses were recorded
microneurographically. Responses were plotted in raster form to produce a
neural image of the pattern. Responses of rapidly and slowly adapting type
I (FAI and SAI) afferents resolved dots down to a spacing of about 1.5 mm.
Responses of type II (FAII and SAII) afferents resolved dots down to a
spacing of about 3.5 mm. Variation in scanning speed (range, 20-90 mm/sec)
and contact force (range, 0.4-1.0 N) had minimal effects on spatial
resolution of all afferents. The response clusters associated with
individual widely spaced dots were used to investigate receptive field
structure. FAI and SAI fields (mean areas, 6.1 and 4.8 mm2, respectively)
each contained several zones of maximal sensitivity. FAI fields had five to
eight such zones, whereas SAI fields had three to five such zones. As dot
spacing decreased, neighboring dots interacted to affect the responses
associated with the individual zones within a field. Initially, one or more
zones were deactivated, effectively reducing receptive field size and
allowing representation of finer spatial detail than would be predicted
from the overall area of the receptive field. At very close dot spacings
responses were only obtained when more than one sensitive zone within a
field were simultaneously activated by different dots.
This article has been cited by other articles:
|
|
|
|
 
S. J. Bensmaia, J. C. Craig, T. Yoshioka, and K. O. Johnson
SA1 and RA Afferent Responses to Static and Vibrating Gratings
J Neurophysiol,
March 1, 2006;
95(3):
1771 - 1782.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. J. Bensmaia, J. C. Craig, and K. O. Johnson
Temporal Factors in Tactile Spatial Acuity: Evidence for RA Interference in Fine Spatial Processing
J Neurophysiol,
March 1, 2006;
95(3):
1783 - 1791.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. T. Blake and M. M. Merzenich
Changes of AI Receptive Fields With Sound Density
J Neurophysiol,
December 1, 2002;
88(6):
3409 - 3420.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. Birznieks, P. Jenmalm, A. W. Goodwin, and R. S. Johansson
Encoding of Direction of Fingertip Forces by Human Tactile Afferents
J. Neurosci.,
October 15, 2001;
21(20):
8222 - 8237.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. Yoshioka, B. Gibb, A. K. Dorsch, S. S. Hsiao, and K. O. Johnson
Neural Coding Mechanisms Underlying Perceived Roughness of Finely Textured Surfaces
J. Neurosci.,
September 1, 2001;
21(17):
6905 - 6916.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. R. Ponsford and R. W. Van Boven
Tactile spatial resolution in blind Braille readers
Neurology,
November 28, 2000;
55(10):
1597 - 1597.
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. W. V. Boven, R. H. Hamilton, T. Kauffman, J. P. Keenan, and A. Pascual-Leone
Tactile spatial resolution in blind Braille readers
Neurology,
June 27, 2000;
54(12):
2230 - 2236.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. W. Goodwin and H. E. Wheat
Effects of Nonuniform Fiber Sensitivity, Innervation Geometry, and Noise on Information Relayed by a Population of Slowly Adapting Type I Primary Afferents from the Fingerpad
J. Neurosci.,
September 15, 1999;
19(18):
8057 - 8070.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. Vega-Bermudez and K. O. Johnson
SA1 and RA Receptive Fields, Response Variability, and Population Responses Mapped with a Probe Array
J Neurophysiol,
June 1, 1999;
81(6):
2701 - 2710.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. Vega-Bermudez and K. O. Johnson
Surround Suppression in the Responses of Primate SA1 and RA Mechanoreceptive Afferents Mapped with a Probe Array
J Neurophysiol,
June 1, 1999;
81(6):
2711 - 2719.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. J. DiCarlo and K. O. Johnson
Velocity Invariance of Receptive Field Structure in Somatosensory Cortical Area 3b of the Alert Monkey
J. Neurosci.,
January 1, 1999;
19(1):
401 - 419.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. W. Goodwin, V. G. Macefield, and J. W. Bisley
Encoding of Object Curvature by Tactile Afferents From Human Fingers
J Neurophysiol,
December 1, 1997;
78(6):
2881 - 2888.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. T. Blake, K. O. Johnson, and S. S. Hsiao
Monkey Cutaneous SAI and RA Responses to Raised and Depressed Scanned Patterns: Effects of Width, Height, Orientation, and a Raised Surround
J Neurophysiol,
November 1, 1997;
78(5):
2503 - 2517.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. T. Blake, S. S. Hsiao, and K. O. Johnson
Neural Coding Mechanisms in Tactile Pattern Recognition: The Relative Contributions of Slowly and Rapidly Adapting Mechanoreceptors to Perceived Roughness
J. Neurosci.,
October 1, 1997;
17(19):
7480 - 7489.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Z. Mainen and T. Sejnowski
Reliability of spike timing in neocortical neurons
Science,
June 9, 1995;
268(5216):
1503 - 1506.
[Abstract]
[PDF]
|
|
|
|
