Comparative neurophysiology of spatial luminance contrast sensitivity.

Souza, Givago da Silva; Gomès, Bruno; Silveira, Luiz Carlos de Lima

doi:10.3922/j.psns.2011.1.005

Cited by 33 publications

(16 citation statements)

References 185 publications

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“…When determining the perception of colour patterns in other animals, it is therefore essential to consider spatial acuity (and viewing distance) as well as colour and luminance discrimination abilities (Endler, ). Humans have greater spatial acuity and contrast sensitivity than most vertebrates, except for some birds (Caves, Frank, & Johnsen, ; da Silva Souza, Gomes, & Silveira, ). We also have a different number of receptor classes, and different spectral sensitivity ranges compared to many animals (Cronin et al, ).…”

Section: Introductionmentioning

confidence: 99%

Quantitative Colour Pattern Analysis (QCPA): A comprehensive framework for the analysis of colour patterns in nature

et al. 2019

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1. To understand the function of colour signals in nature, we require robust quantitative analytical frameworks to enable us to estimate how animal and plant colour patterns appear against their natural background as viewed by ecologically relevant species. Due to the quantitative limitations of existing methods, colour and pattern are rarely analysed in conjunction with one another, despite a large body of literature and decades of research on the importance of spatio-chromatic colour pattern analyses. Furthermore, key physiological limitations of animal visual systems such as spatial acuity, spectral sensitivities, photoreceptor abundances and receptor noise levels are rarely considered together in colour pattern analyses.2. Here, we present a novel analytical framework, called the Quantitative Colour Pattern Analysis (QCPA). We have overcome many quantitative and qualitative limitations of existing colour pattern analyses by combining calibrated digital photography and visual modelling. We have integrated and updated existing spatio-chromatic colour pattern analyses, including adjacency, visual contrast and boundary strength analysis, to be implemented using calibrated digital photography through the Multispectral Image Analysis and Calibration (MICA) Toolbox.3. This combination of calibrated photography and spatio-chromatic colour pattern analyses is enabled by the inclusion of psychophysical colour and luminance discrimination thresholds for image segmentation, which we call 'Receptor Noise Limited Clustering', used here for the first time. Furthermore, QCPA provides a novel psycho-physiological approach to the modelling of spatial acuity using convolution in the spatial or frequency domains, followed by 'Receptor Noise Limited Ranked Filtering' to eliminate intermediate edge artefacts and recover sharp boundaries following smoothing. We also present a new type of colour pattern analysis, the 'local edge intensity analysis' as well as a range of novel psycho-physiological approaches to the visualization of spatio-chromatic data. QCPA combines novel and existing pattern analysis frameworks into what we hope is a unified, free and open source toolbox and introduces a range of novel analyticalThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

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Section: Introductionmentioning

confidence: 99%

Quantitative Colour Pattern Analysis (QCPA): A comprehensive framework for the analysis of colour patterns in nature

et al. 2019

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“…For example, the night-active mouse develops a rod-rich NR required for proper vision at night and therefore does not need to develop a cone-rich macula/fovea centralis. As such, during the day, visual acuity is impaired in mice when compared to birds or humans ( Da Silva Souza et al, 2011 ; Baker, 2013 ). In this study, we used the developing chick embryo as an ideal model system to better understand human eye development and disease.…”

Section: Discussionmentioning

confidence: 99%

BMP-induced reprograming of the retina into RPE requires WNT signalling in the developing chick optic cup

Steinfeld¹,

Steinfeld²,

Bausch³

et al. 2017

Biology Open

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In vertebrates, the retinal pigment epithelium (RPE) and photoreceptors of the neural retina (NR) comprise a functional unit required for vision. During vertebrate eye development, a conversion of the RPE into NR can be induced by growth factors in vivo at optic cup stages, but the reverse process, the conversion of NR tissue into RPE, has not been reported. Here, we show that bone morphogenetic protein (BMP) signalling can reprogram the NR into RPE at optic cup stages in chick. Shortly after BMP application, expression of Microphthalmia-associated transcription factor (Mitf) is induced in the NR and selective cell death on the basal side of the NR induces an RPE-like morphology. The newly induced RPE differentiates and expresses Melanosomalmatrix protein 115 (Mmp115) and RPE65. BMP-induced Wnt2b expression is observed in regions of the NR that become pigmented. Loss of function studies show that conversion of the NR into RPE requires both BMP and Wnt signalling. Simultaneous to the appearance of ectopic RPE tissue, BMP application reprogrammed the proximal RPE into multi-layered retinal tissue. The newly induced NR expresses visual segment homeobox-containing gene (Vsx2), and the ganglion and photoreceptor cell markers Brn3α and Visinin are detected. Our results show that high BMP concentrations are required to induce the conversion of NR into RPE, while low BMP concentrations can still induce transdifferentiation of the RPE into NR. This knowledge may contribute to the development of efficient standardized protocols for RPE and NR generation for cell replacement therapies.

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“…However, contrast sensitivity has been measured using sinusoidal gratings (da Silva Souza et al, 2011). In these experiments, contrast sensitivity is often measured as a function of the number of cycles deg −1 of a grating stimulus (Pelli and Bex, 2013).…”

Section: Discussionmentioning

confidence: 99%

Multimodal integration in behaving chickens

Verhaal

Luksch

2015

Journal of Experimental Biology

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In everyday life we constantly perceive and discriminate between a large variety of sensory inputs, the vast majority of which consist of more than one modality. We performed two experiments to investigate whether chickens use the information present in multimodal signals. To test whether audiovisual stimuli are better detected than visual or acoustic stimuli alone, we first measured the detection threshold with a staircase paradigm. We found that chickens were able to detect weaker stimuli using audiovisual stimuli. Next, we tested whether the multimodal nature of a stimulus also increases the discrimination between two stimuli by measuring the smallest difference that the animals could still distinguish from each other. We found that chickens can discriminate smaller differences using audiovisual stimuli in comparison to visual stimuli alone, but not in comparison to acoustic stimuli alone. Thus, even in a relatively unspecialized species such as the chicken, the benefits of multimodal integration are exploited for sensory processing.

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Comparative neurophysiology of spatial luminance contrast sensitivity.

Cited by 33 publications

References 185 publications

Quantitative Colour Pattern Analysis (QCPA): A comprehensive framework for the analysis of colour patterns in nature

Quantitative Colour Pattern Analysis (QCPA): A comprehensive framework for the analysis of colour patterns in nature

BMP-induced reprograming of the retina into RPE requires WNT signalling in the developing chick optic cup

Multimodal integration in behaving chickens

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