Abstract
The maximum area of complete spatial summation (i.e., Ricco's area) for human short-wavelength-sensitive(S-) and long-wavelength-sensitive- (L-) cone mechanisms was measured psychophysically at the fovea and at 1.5°, 4°, 8°, and 20° along the vertical meridian in the superior retina. Increment thresholds were measured for three observers by a temporal two-alternative forced-choice procedure. Test stimuli ranging from -0.36 to 4.61 log area (min2) were presented on concentric 12.3° adapting and auxiliary fields, which isolated either an S- or an L-cone mechanism on the plateau of its respective threshold versus intensity function. Test flash durations were 50 and 10 ms for the S- and L-cone mechanisms, respectively. The data indicate that, from 0° to 20°, Ricco's area increases monotonically for the L-cone mechanism, is variable for the S-cone mechanism, and is larger for the S-cone mechanism than for the L-cone mechanism for essentially all retinal locations. This pattern of results most likely reflects differences in ganglion cell density and changes in neural convergence with retinal eccentricity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 641-650 |
| Number of pages | 10 |
| Journal | Journal of the Optical Society of America A: Optics and Image Science, and Vision |
| Volume | 17 |
| Issue number | 3 |
| State | Published - 2000 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Computer Vision and Pattern Recognition
Cite this
Spatial summation in human cone mechanisms from 0° to 20° in the superior retina. / Volbrecht, Vicki J.; Shrago, Erin E.; Schefrin, Brooke E.; Werner, John S.
In: Journal of the Optical Society of America A: Optics and Image Science, and Vision, Vol. 17, No. 3, 2000, p. 641-650.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Spatial summation in human cone mechanisms from 0° to 20° in the superior retina
AU - Volbrecht, Vicki J.
AU - Shrago, Erin E.
AU - Schefrin, Brooke E.
AU - Werner, John S
PY - 2000
Y1 - 2000
N2 - The maximum area of complete spatial summation (i.e., Ricco's area) for human short-wavelength-sensitive(S-) and long-wavelength-sensitive- (L-) cone mechanisms was measured psychophysically at the fovea and at 1.5°, 4°, 8°, and 20° along the vertical meridian in the superior retina. Increment thresholds were measured for three observers by a temporal two-alternative forced-choice procedure. Test stimuli ranging from -0.36 to 4.61 log area (min2) were presented on concentric 12.3° adapting and auxiliary fields, which isolated either an S- or an L-cone mechanism on the plateau of its respective threshold versus intensity function. Test flash durations were 50 and 10 ms for the S- and L-cone mechanisms, respectively. The data indicate that, from 0° to 20°, Ricco's area increases monotonically for the L-cone mechanism, is variable for the S-cone mechanism, and is larger for the S-cone mechanism than for the L-cone mechanism for essentially all retinal locations. This pattern of results most likely reflects differences in ganglion cell density and changes in neural convergence with retinal eccentricity.
AB - The maximum area of complete spatial summation (i.e., Ricco's area) for human short-wavelength-sensitive(S-) and long-wavelength-sensitive- (L-) cone mechanisms was measured psychophysically at the fovea and at 1.5°, 4°, 8°, and 20° along the vertical meridian in the superior retina. Increment thresholds were measured for three observers by a temporal two-alternative forced-choice procedure. Test stimuli ranging from -0.36 to 4.61 log area (min2) were presented on concentric 12.3° adapting and auxiliary fields, which isolated either an S- or an L-cone mechanism on the plateau of its respective threshold versus intensity function. Test flash durations were 50 and 10 ms for the S- and L-cone mechanisms, respectively. The data indicate that, from 0° to 20°, Ricco's area increases monotonically for the L-cone mechanism, is variable for the S-cone mechanism, and is larger for the S-cone mechanism than for the L-cone mechanism for essentially all retinal locations. This pattern of results most likely reflects differences in ganglion cell density and changes in neural convergence with retinal eccentricity.
UR - http://www.scopus.com/inward/record.url?scp=0034146761&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034146761&partnerID=8YFLogxK
M3 - Article
C2 - 10708046
AN - SCOPUS:0034146761
VL - 17
SP - 641
EP - 650
JO - Journal of the Optical Society of America. A, Optics and image science
JF - Journal of the Optical Society of America. A, Optics and image science
SN - 1084-7529
IS - 3
ER -