1
|
Greene MJ, Boehm AE, Vanston JE, Pandiyan VP, Sabesan R, Tuten WS. Unique yellow shifts for small and brief stimuli in the central retina. J Vis 2024; 24:2. [PMID: 38833255 PMCID: PMC11156209 DOI: 10.1167/jov.24.6.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 05/01/2024] [Indexed: 06/06/2024] Open
Abstract
The spectral locus of unique yellow was determined for flashes of different sizes (<11 arcmin) and durations (<500 ms) presented in and near the fovea. An adaptive optics scanning laser ophthalmoscope was used to minimize the effects of higher-order aberrations during simultaneous stimulus delivery and retinal imaging. In certain subjects, parafoveal cones were classified as L, M, or S, which permitted the comparison of unique yellow measurements with variations in local L/M ratios within and between observers. Unique yellow shifted to longer wavelengths as stimulus size or duration was reduced. This effect is most pronounced for changes in size and more apparent in the fovea than in the parafovea. The observed variations in unique yellow are not entirely predicted from variations in L/M ratio and therefore implicate neural processes beyond photoreception.
Collapse
Affiliation(s)
- Maxwell J Greene
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, USA
| | - Alexandra E Boehm
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, USA
| | - John E Vanston
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, USA
| | - Vimal P Pandiyan
- Department of Ophthalmology, University of Washington, Seattle, WA, USA
| | - Ramkumar Sabesan
- Department of Ophthalmology, University of Washington, Seattle, WA, USA
| | - William S Tuten
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, USA
| |
Collapse
|
2
|
Hunter AML, Anderson RS, Redmond T, Garway-Heath DF, Mulholland PJ. Investigating the Spatiotemporal Summation of Perimetric Stimuli in Dry Age-Related Macular Degeneration. Transl Vis Sci Technol 2023; 12:37. [PMID: 38019498 PMCID: PMC10691387 DOI: 10.1167/tvst.12.11.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 09/26/2023] [Indexed: 11/30/2023] Open
Abstract
Purpose To measure achromatic spatial, temporal, and spatiotemporal summation in dry age-related macular degeneration (AMD) compared to healthy controls under conditions of photopic gaze-contingent perimetry. Methods Twenty participants with dry AMD (mean age, 74.6 years) and 20 healthy controls (mean age, 67.8 years) performed custom, gaze-contingent perimetry tests. An area-modulation test generated localized estimates of Ricco's area (RA) at 2.5° and 5° eccentricities along the 0°, 90°, 180°, and 270° meridians. Contrast thresholds were measured at the same test locations for stimuli of six durations (3.7-190.4 ms) with a Goldmann III stimulus (GIII, 0.43°) and RA-scaled stimuli. The upper limit (critical duration) of complete temporal summation (using the GIII stimulus) and spatiotemporal summation (using the RA stimuli) was estimated using iterative two-phase regression analysis. Results Median (interquartile range [IQR]) RA estimates were significantly larger in AMD participants (2.5°: 0.21 [0.09-0.41] deg2; 5°: 0.32 [0.15-0.65 deg2]) compared to healthy controls (2.5°: 0.08 [0.05-0.13] deg2; 5°: 0.15 [0.08-0.22] deg2) at all test locations (all P < 0.05). No significant difference in median critical duration was found in AMD participants with the GIII stimulus (19.6 [9.9-30.4] ms) and RA-scaled stimuli (22.9 [13.9-40.3] ms) compared to healthy controls (GIII: 17.0 [11.3-24.0] ms; RA-scaled: 22.4 [14.3-33.1] ms) at all test locations (all P > 0.05). Conclusions Spatial summation is altered in dry AMD, without commensurate changes in temporal summation. Translational Relevance The sensitivity of perimetry to AMD may be improved by utilizing stimuli that probe alterations in spatial summation in the disease.
Collapse
Affiliation(s)
- Aoife M. L. Hunter
- Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
| | - Roger S. Anderson
- Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
- National Institute for Health Research Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Tony Redmond
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - David F. Garway-Heath
- National Institute for Health Research Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Pádraig J. Mulholland
- Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, UK
- National Institute for Health Research Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| |
Collapse
|
3
|
Morgan JIW, Chui TYP, Grieve K. Twenty-five years of clinical applications using adaptive optics ophthalmoscopy [Invited]. BIOMEDICAL OPTICS EXPRESS 2023; 14:387-428. [PMID: 36698659 PMCID: PMC9841996 DOI: 10.1364/boe.472274] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/22/2022] [Accepted: 11/27/2022] [Indexed: 05/02/2023]
Abstract
Twenty-five years ago, adaptive optics (AO) was combined with fundus photography, thereby initiating a new era in the field of ophthalmic imaging. Since that time, clinical applications of AO ophthalmoscopy to investigate visual system structure and function in both health and disease abound. To date, AO ophthalmoscopy has enabled visualization of most cell types in the retina, offered insight into retinal and systemic disease pathogenesis, and been integrated into clinical trials. This article reviews clinical applications of AO ophthalmoscopy and addresses remaining challenges for AO ophthalmoscopy to become fully integrated into standard ophthalmic care.
Collapse
Affiliation(s)
- Jessica I. W. Morgan
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Contributed equally
| | - Toco Y. P. Chui
- Department of Ophthalmology, The New York Eye and Ear Infirmary of Mount Sinai, New York, NY 10003, USA
- Contributed equally
| | - Kate Grieve
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, and CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, F-75012 Paris, France
- Contributed equally
| |
Collapse
|
4
|
Warner RL, Brainard DH, Morgan JIW. Repeatability and reciprocity of the cone optoretinogram. BIOMEDICAL OPTICS EXPRESS 2022; 13:6561-6573. [PMID: 36589578 PMCID: PMC9774868 DOI: 10.1364/boe.471990] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/08/2022] [Accepted: 11/08/2022] [Indexed: 05/02/2023]
Abstract
Optoretinography has enabled noninvasive visualization of physiological changes in cone photoreceptors exposed to light. Understanding the cone optoretinogram in healthy subjects is essential for establishing it as a biomarker for cone function in disease. Here, we measure the population cone intensity optoretinogram in healthy adults, for multiple irradiance/duration combinations of visible stimuli with equal energy. We study the within and between session repeatability and reciprocity of the ORG in five healthy subjects. We find the cone optoretinogram exhibits equivalent amplitudes for equal-energy stimuli. We also find good within-subject repeatability, which allows us to show differences across the five subjects.
Collapse
Affiliation(s)
- R. L. Warner
- Scheie Eye Institute, Department of
Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - D. H. Brainard
- Psychology Department, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - J. I. W. Morgan
- Scheie Eye Institute, Department of
Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center for Advanced Retinal and Ocular
Therapeutics, University of Pennsylvania,
Philadelphia, PA, 19104, USA
| |
Collapse
|
5
|
Domdei N, Reiniger JL, Holz FG, Harmening WM. The Relationship Between Visual Sensitivity and Eccentricity, Cone Density and Outer Segment Length in the Human Foveola. Invest Ophthalmol Vis Sci 2021; 62:31. [PMID: 34289495 PMCID: PMC8300048 DOI: 10.1167/iovs.62.9.31] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Purpose The cellular topography of the human foveola, the central 1° diameter of the fovea, is strikingly non-uniform, with a steep increase of cone photoreceptor density and outer segment (OS) length toward its center. Here, we assessed to what extent the specific cellular organization of the foveola of an individual is reflected in visual sensitivity and if sensitivity peaks at the preferred retinal locus of fixation (PRL). Methods Increment sensitivity to small-spot, cone-targeted visual stimuli (1 × 1 arcmin, 543-nm light) was recorded psychophysically in four human participants at 17 locations concentric within a 0.2° diameter on and around the PRL with adaptive optics scanning laser ophthalmoscopy-based microstimulation. Sensitivity test spots were aligned with cell-resolved maps of cone density and cone OS length. Results Peak sensitivity was at neither the PRL nor the topographical center of the cone mosaic. Within the central 0.1° diameter, a plateau-like sensitivity profile was observed. Cone density and maximal OS length differed significantly across participants, correlating with their peak sensitivity. Based on these results, biophysical simulation allowed to develop a model of visual sensitivity in the foveola, with distance from the PRL (eccentricity), cone density, and OS length as parameters. Conclusions Small-spot sensitivity thresholds in healthy retinas will help to establish the range of normal foveolar function in cell-targeted vision testing. Because of the high reproducibility in replicate testing, threshold variability not explained by our model is assumed to be caused by individual cone and bipolar cell weighting at the specific target locations.
Collapse
Affiliation(s)
- Niklas Domdei
- Department of Ophthalmology, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Jenny L Reiniger
- Department of Ophthalmology, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Frank G Holz
- Department of Ophthalmology, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Wolf M Harmening
- Department of Ophthalmology, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| |
Collapse
|
6
|
Abstract
In this review, I develop an empirically based model of optical image formation by the human eye, followed by neural sampling by retinal ganglion cells, to demonstrate the perceptual effects of blur, aliasing, and distortion of visual space in the brain. The optical model takes account of ocular aberrations and their variation across the visual field, in addition to variations of defocus due to variation of target vergence in three-dimensional scenes. Neural sampling by retinal ganglion cells with receptive field size and spacing that increases with eccentricity is used to visualize the neural image carried by the optic nerve to the brain. Anatomical parameters are derived from psychophysical studies of sampling-limited visual resolution of sinusoidal interference fringes. Retinotopic projection of the neural image onto brainstem nuclei reveals features of the neural image in a perceptually uniform brain space where location and size of visual objects may be measured by counting neurons.
Collapse
Affiliation(s)
- Larry N Thibos
- School of Optometry, Indiana University, Bloomington, Indiana 47405, USA;
| |
Collapse
|
7
|
Siderov J, Pluháček F, Bedell HE. Upturn of the contour-interaction function at small flanking bar-to-target separations. Vision Res 2020; 167:1-7. [DOI: 10.1016/j.visres.2019.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 12/05/2019] [Accepted: 12/11/2019] [Indexed: 11/25/2022]
|
8
|
Abstract
Textbook trichromacy accounts for human color vision in terms of spectral sampling by three classes of cone photoreceptors. This account neglects entangling of color and pattern information created by wavelength-dependent optical blur (chromatic aberrations) and interleaved spatial sampling of the retinal image by the three classes of cones. Recent experimental, computational, and neurophysiological work is now considering color and pattern vision at the elementary scale of daylight vison, that is at the scale of individual cones. The results provide insight about rich interactions between color and pattern vision as well as the role of the statistical structure of natural scenes in shaping visual processing.
Collapse
Affiliation(s)
- David H Brainard
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, 19104
| |
Collapse
|
9
|
Domdei N, Linden M, Reiniger JL, Holz FG, Harmening WM. Eye tracking-based estimation and compensation of chromatic offsets for multi-wavelength retinal microstimulation with foveal cone precision. BIOMEDICAL OPTICS EXPRESS 2019; 10:4126-4141. [PMID: 31452999 PMCID: PMC6701545 DOI: 10.1364/boe.10.004126] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/07/2019] [Accepted: 06/07/2019] [Indexed: 05/20/2023]
Abstract
Multi-wavelength ophthalmic imaging and stimulation of photoreceptor cells require consideration of chromatic dispersion of the eye, manifesting in longitudinal and transverse chromatic aberrations. Contemporary image-based techniques to measure and correct transverse chromatic aberration (TCA) and the resulting transverse chromatic offset (TCO) in an adaptive optics retinal imaging system are precise but lack compensation of small but significant shifts in eye position occurring during in vivo testing. Here, we present a method that requires only a single measurement of TCO during controlled movements of the eye to map retinal chromatic image shifts to the image space of a pupil camera. After such calibration, TCO can be compensated by continuously monitoring eye position during experimentation and by interpolating correction vectors from a linear fit to the calibration data. The average change rate of TCO per head shift and the correlation between Kappa and the individual foveal TCA are close to the expectations based on a chromatic eye model. Our solution enables continuous compensation of TCO with high spatial precision and avoids high light intensities required for re-measuring TCO after eye position changes, which is necessary for foveal cone-targeted psychophysical experimentation.
Collapse
|
10
|
Cottaris NP, Jiang H, Ding X, Wandell BA, Brainard DH. A computational-observer model of spatial contrast sensitivity: Effects of wave-front-based optics, cone-mosaic structure, and inference engine. J Vis 2019; 19:8. [PMID: 30943530 DOI: 10.1167/19.4.8] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We present a computational-observer model of the human spatial contrast-sensitivity function based on the Image Systems Engineering Toolbox for Biology (ISETBio) simulation framework. We demonstrate that ISETBio-derived contrast-sensitivity functions agree well with ones derived using traditional ideal-observer approaches, when the mosaic, optics, and inference engine are matched. Further simulations extend earlier work by considering more realistic cone mosaics, more recent measurements of human physiological optics, and the effect of varying the inference engine used to link visual representations to psychophysical performance. Relative to earlier calculations, our simulations show that the spatial structure of realistic cone mosaics reduces the upper bounds on performance at low spatial frequencies, whereas realistic optics derived from modern wave-front measurements lead to increased upper bounds at high spatial frequencies. Finally, we demonstrate that the type of inference engine used has a substantial effect on the absolute level of predicted performance. Indeed, the performance gap between an ideal observer with exact knowledge of the relevant signals and human observers is greatly reduced when the inference engine has to learn aspects of the visual task. ISETBio-derived estimates of stimulus representations at various stages along the visual pathway provide a powerful tool for computing the limits of human performance.
Collapse
Affiliation(s)
- Nicolas P Cottaris
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Haomiao Jiang
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Xiaomao Ding
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Brian A Wandell
- Department of Psychology, Stanford University, Stanford, CA, USA
| | - David H Brainard
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
11
|
Schmidt BP, Boehm AE, Foote KG, Roorda A. The spectral identity of foveal cones is preserved in hue perception. J Vis 2019; 18:19. [PMID: 30372729 PMCID: PMC6205561 DOI: 10.1167/18.11.19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Organisms are faced with the challenge of making inferences about the physical world from incomplete incoming sensory information. One strategy to combat ambiguity in this process is to combine new information with prior experiences. We investigated the strategy of combining these information sources in color vision. Single cones in human subjects were stimulated and the associated percepts were recorded. Subjects rated each flash for brightness, hue, and saturation. Brightness ratings were proportional to stimulus intensity. Saturation was independent of intensity, but varied between cones. Hue, in contrast, was assigned in a stereotyped manner that was predicted by cone type. These experiments revealed that, near the fovea, long and middle wavelength sensitive cones produce sensations that can be reliably distinguished on the basis of hue, but not saturation or brightness. Taken together, these observations implicate the high-resolution, color-opponent parvocellular pathway in this low-level visual task.
Collapse
Affiliation(s)
- Brian P Schmidt
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, CA, USA
| | - Alexandra E Boehm
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, CA, USA
| | - Katharina G Foote
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, CA, USA
| | - Austin Roorda
- School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, CA, USA
| |
Collapse
|
12
|
Tuten WS, Vergilio GK, Young GJ, Bennett J, Maguire AM, Aleman TS, Brainard DH, Morgan JIW. Visual Function at the Atrophic Border in Choroideremia Assessed with Adaptive Optics Microperimetry. Ophthalmol Retina 2019; 3:888-899. [PMID: 31235310 DOI: 10.1016/j.oret.2019.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/12/2019] [Accepted: 05/01/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE Recent advances in retinal imaging allow visualization of structural abnormalities in retinal disease at the cellular level. This study used adaptive optics (AO) microperimetry to assess visual sensitivity with high spatial precision and to examine how function varies across 2 phenotypic features observed in choroideremia: atrophic lesion borders and outer retinal tubulations (ORTs). DESIGN Cross-sectional study. PARTICIPANTS Twelve choroideremia patients. METHODS A custom AO scanning light ophthalmoscope (AOSLO) equipped with both confocal and nonconfocal split-detection imaging methods was used to image the photoreceptor inner and outer segment mosaics. For AO microperimetry, circular 550-nm stimuli were presented through the AOSLO system; stimuli were either 9.6 or 38.3 arcmin2 (approximately 60 or 15 times smaller than a Goldman III stimulus). Test locations were identified in structural images and stimuli were targeted to these locations using real-time retinal tracking combined with measurements of transverse chromatic aberration. Psychophysical detection thresholds were measured at the atrophic border in 12 patients. Additionally, visual sensitivity was probed along ORTs in 4 patients. MAIN OUTCOME MEASURE Visual sensitivity thresholds measured with AO microperimetry at retinal locations corresponding to structural phenotypes observed on AOSLO retinal images. RESULTS In choroideremia, sharp borders between intact central islands of the photoreceptor mosaic and complete atrophy of the outer retina and retinal pigment epithelium were observed in both split-detection and confocal structural images. Adaptive optics microperimetry at locations spanning these borders showed a commensurately sharp decrease in function, with readily measurable visual sensitivity on one side and dense scotoma on the other. These functional transitions often occurred over a distance smaller than the diameter of the Goldman III stimulus. Thresholds measured along ORTs showed dense scotoma over the tubule in all 4 participants, despite the visibility of remnant cone inner segments on the AO images. CONCLUSIONS Choroideremia patients exhibited sharp functional transitions that collocated with structural transitions from intact to severely degenerated retina. We found no evidence of visual sensitivity over ORTs. Measuring cone function with high resolution offered insight into disease mechanisms and may enable precise assessment of whether experimental therapies, such as gene therapy, provide a functional benefit.
Collapse
Affiliation(s)
- William S Tuten
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Grace K Vergilio
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania; Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Gloria J Young
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania; Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jean Bennett
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania; Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Albert M Maguire
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania; Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Tomas S Aleman
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania; Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David H Brainard
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jessica I W Morgan
- Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania; Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania.
| |
Collapse
|
13
|
Kupers ER, Carrasco M, Winawer J. Modeling visual performance differences 'around' the visual field: A computational observer approach. PLoS Comput Biol 2019; 15:e1007063. [PMID: 31125331 PMCID: PMC6553792 DOI: 10.1371/journal.pcbi.1007063] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 06/06/2019] [Accepted: 05/02/2019] [Indexed: 01/25/2023] Open
Abstract
Visual performance depends on polar angle, even when eccentricity is held constant; on many psychophysical tasks observers perform best when stimuli are presented on the horizontal meridian, worst on the upper vertical, and intermediate on the lower vertical meridian. This variation in performance 'around' the visual field can be as pronounced as that of doubling the stimulus eccentricity. The causes of these asymmetries in performance are largely unknown. Some factors in the eye, e.g. cone density, are positively correlated with the reported variations in visual performance with polar angle. However, the question remains whether these correlations can quantitatively explain the perceptual differences observed 'around' the visual field. To investigate the extent to which the earliest stages of vision-optical quality and cone density-contribute to performance differences with polar angle, we created a computational observer model. The model uses the open-source software package ISETBIO to simulate an orientation discrimination task for which visual performance differs with polar angle. The model starts from the photons emitted by a display, which pass through simulated human optics with fixational eye movements, followed by cone isomerizations in the retina. Finally, we classify stimulus orientation using a support vector machine to learn a linear classifier on the photon absorptions. To account for the 30% increase in contrast thresholds for upper vertical compared to horizontal meridian, as observed psychophysically on the same task, our computational observer model would require either an increase of ~7 diopters of defocus or a reduction of 500% in cone density. These values far exceed the actual variations as a function of polar angle observed in human eyes. Therefore, we conclude that these factors in the eye only account for a small fraction of differences in visual performance with polar angle. Substantial additional asymmetries must arise in later retinal and/or cortical processing.
Collapse
Affiliation(s)
- Eline R. Kupers
- Department of Psychology, New York University, New York, New York, United States of America
| | - Marisa Carrasco
- Department of Psychology, New York University, New York, New York, United States of America
- Center for Neural Science, New York University, New York, New York, United States of America
| | - Jonathan Winawer
- Department of Psychology, New York University, New York, New York, United States of America
- Center for Neural Science, New York University, New York, New York, United States of America
| |
Collapse
|
14
|
Thibos LN, Bradley A, Xu R, Lopez-Gil N. Ricco's law and absolute threshold for foveal detection of black holes. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2019; 36:B35-B43. [PMID: 31044953 DOI: 10.1364/josaa.36.000b35] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
Visual detection of small black objects surrounded by a light background depends on background luminance, pupil size, optical blur, and object size. Holding pupil and optics fixed, we measured the minimum background luminance needed for foveal detection of small black targets as a function of target size. For all three observers, absolute threshold varied inversely with target area when disk diameter subtended less than 10' of visual angle. For target diameter ≥10', threshold remained constant at about 0.3 Td, which was also the absolute threshold for detecting light spots 10' or larger in diameter on a black background. These results are consistent with Ricco's law of spatial summation: a "black hole" is just detectable when the background luminance is sufficiently high for its absence inside the Ricco area to reduce 555 nm photon flux by 7500 photons/s, which is the same change needed to detect light spots on a black surround. These results can be accounted for by a differential pair of Ricco detectors, each about the size of the receptive field center of magocellular retinal ganglion cells when projected into object space through the eye's weakly aberrated optical system. Statistical analysis of the model suggests the quantum fluctuations due to internal, biological noise (i.e., "scotons") are a greater handicap than the photon fluctuations inherent in the light stimulus at absolute foveal threshold.
Collapse
|
15
|
Kling A, Field GD, Brainard DH, Chichilnisky EJ. Probing Computation in the Primate Visual System at Single-Cone Resolution. Annu Rev Neurosci 2019; 42:169-186. [PMID: 30857477 DOI: 10.1146/annurev-neuro-070918-050233] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Daylight vision begins when light activates cone photoreceptors in the retina, creating spatial patterns of neural activity. These cone signals are then combined and processed in downstream neural circuits, ultimately producing visual perception. Recent technical advances have made it possible to deliver visual stimuli to the retina that probe this processing by the visual system at its elementary resolution of individual cones. Physiological recordings from nonhuman primate retinas reveal the spatial organization of cone signals in retinal ganglion cells, including how signals from cones of different types are combined to support both spatial and color vision. Psychophysical experiments with human subjects characterize the visual sensations evoked by stimulating a single cone, including the perception of color. Future combined physiological and psychophysical experiments focusing on probing the elementary visual inputs are likely to clarify how neural processing generates our perception of the visual world.
Collapse
Affiliation(s)
- A Kling
- Departments of Neurosurgery and Ophthalmology, Stanford University School of Medicine, Stanford, California 94305, USA;
| | - G D Field
- Department of Neurobiology, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - D H Brainard
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - E J Chichilnisky
- Departments of Neurosurgery and Ophthalmology, Stanford University School of Medicine, Stanford, California 94305, USA;
| |
Collapse
|