The spectral identity of foveal cones is preserved in hue perception

Abstract

6 Organisms are faced with the challenge of making inferences about the physical world from incomplete 7 incoming sensory information. One strategy to combat ambiguity in this process is to combine new infor-8 mation with prior experiences. We investigated the strategy of combining these information sources in color 9 vision. Single cones in human subjects were stimulated and the associated percepts were recorded. Subjects 10 rated each flash for brightness, hue and saturation. Brightness ratings were proportional to stimulus inten-11 sity. Saturation was independent of intensity, but varied between cones. Hue, in contrast, was assigned in a 12 stereotyped manner that was predicted by cone type. These experiments revealed that long (L) and middle

Spatial summation of individual cones in human color vision

“…Consequently, signal to noise ratio 20 (SNR) is reduced and summation becomes sub-linear. The magnocellular pathway is 21 often cited as a possible neural correlate of this phenomenon [3][4][5]. Recently, this idea 22 was tested by Bruce [6], who measured summation on a cellular scale using an adaptive 23 optics scanning laser ophthalmoscope (AOSLO).…”

“…When a spot exceeds the size of a single 18 receptive field, the energy is split over multiple downstream neurons and each additional 19 January 11, 2019 1/15 55 individual cones and identified a few general trends. Firstly, the spectral sensitivity of a 56 probed cone is an important factor governing the elicited percept [21][22][23]. Secondly, 57 even cones with the same spectral sensitivity elicit different colors when probed with 58 identical stimuli [21,24].…”

“…Firstly, the spectral sensitivity of a 56 probed cone is an important factor governing the elicited percept [21][22][23]. Secondly, 57 even cones with the same spectral sensitivity elicit different colors when probed with 58 identical stimuli [21,24]. These observations have been interpreted as evidence that, 59 near the fovea, the visual system learns different information about each cone [21,25].…”

“…A multi-wavelength adaptive optics scanning laser ophthalmoscope (AOSLO) was used 81 to image and present stimuli to the retina. The AOSLO system [26][27][28] and the 82 procedures for stimulating single cones have been described elsewhere in 83 detail [20,21,23]. Briefly, light from a super-continuum laser (SuperK Extreme; NKT 84 Photonics) was split into three channels with interference filters (Semrock): (1) A 940 85 nm channel was used to measure monochromatic aberrations.…”

“…After each trial, subjects judged the hue and saturation with a scaling 160 procedure [21,37]. The subject indicated the percent of red, green, blue, yellow and 161 white contained in each stimulus using five button presses such that each press 162 represented 20% (5x20%=100%).…”