RT info:eu-repo/semantics/article
T1 Influence of background size, luminance and eccentricity on different adaptation mechanisms
A1 Hernán Gloriani, Alejandro
A1 Martínez Matesanz, Cristina Beatriz
A1 Barrionuevo, Pablo Alejandro
A1 Arranz de la Fuente, Isabel
A1 Issolio, Luis
A1 Mar Sardaña, Santiago
A1 Aparicio Calzada, Juan Antonio
K1 Psychophysics
K1 Psicofísica
K1 Visual adaptation
K1 Adaptación visual
K1 Photon noise
K1 Ruido de fotones
K1 2209.15 Optometría
AB Mechanisms of light adaptation have been traditionally explained with reference to psychophysical experimentation. However, the neural substrata involved in those mechanisms remain to be elucidated. Our study analyzed links between psychophysical measurements and retinal physiological evidence with consideration for the phenomena of rod-cone interactions, photon noise, and spatial summation. Threshold test luminances were obtained with steady background fields at mesopic and photopic light levels (i.e., 0.06–110 cd/m2) for retinal eccentricities from 0° to 15° using three combinations of background/test field sizes (i.e., 10°/2°, 10°/0.45°, and 1°/0.45°). A two-channel Maxwellian view optical system was employed to eliminate pupil effects on the measured thresholds. A model based on visual mechanisms that were described in the literature was optimized to fit the measured luminance thresholds in all experimental conditions. Our results can be described by a combination of visual mechanisms. We determined how spatial summation changed with eccentricity and how subtractive adaptation changed with eccentricity and background field size. According to our model, photon noise plays a significant role to explain contrast detection thresholds measured with the 1/0.45° background/test size combination at mesopic luminances and at off-axis eccentricities. In these conditions, our data reflect the presence of rod-cone interaction for eccentricities between 6° and 9° and luminances between 0.6 and 5 cd/m2. In spite of the increasing noise effects with eccentricity, results also show that the visual system tends to maintain a constant signal-to-noise ratio in the off-axis detection task over the whole mesopic range.
PB Elsevier
SN 0042-6989
YR 2016
FD 2016
LK http://uvadoc.uva.es/handle/10324/45123
UL http://uvadoc.uva.es/handle/10324/45123
LA eng
NO Vision Research, 2016, vol. 125. p. 12-22
NO Producción Científica
DS UVaDOC
RD 24-nov-2024