Spectral Sensitivity of Photoreceptors and Colour Vision in the Solitary Bee, Osmia Rufa

1988 ◽  
Vol 136 (1) ◽  
pp. 35-52
Author(s):  
R. MENZEL ◽  
E. STEINMANN ◽  
J. DE SOUZA ◽  
W. BACKHAUS
Keyword(s):  
Spectral Sensitivity ◽  
Colour Vision ◽  
Three Dimensional ◽  
Just Noticeable Difference ◽  
Species Discrimination ◽  
Colour Space ◽  
Absorption Function ◽  
Perceptual Distance ◽  
Line Elements ◽  
Colour Signals

The spectral sensitivity of single photoreceptors of Osmia rufa was determined by a fast voltage-clamp technique. Three receptor types were found whose spectral sensitivity functions followed a rhodopsin-like photopigment absorption function with λmax values at 348nm (ultraviolet receptor), 436nm (blue receptor) and 572nm (green receptor). The λmax of the green receptor in Osmia rufa is shifted to much longer wavelengths compared with other insect species. Discrimination of colour signals was tested after training a bee at the entrance to its nest. The colour signals were filter discs (70 mm in diameter) with a hole (10 mm in diameter) in the centre and the bees quickly learned to use the coloured disc as a marker of the nest entrance. Tests were dual forced-choice tests with two coloured discs closely positioned next to each other. 94 different tests were each repeated 5–15 times and were performed after training to 12 different colour signals. A photoreceptor model was used to calculate the loci of the colour signals in a three-dimensional colour space and in a chromaticity diagram. The perceptual distance between the colour loci was calculated as line elements (minimum number of just noticeable difference, jnd-steps), which were based on the noiseproperties of the photoreceptors. The discrimination determined by the behavioural tests correlated very well with the jnd-steps. The correlation was better for the line elements in the colour plane than in the colour space. Osmia rufa was compared with the honeybee Apis mellifera and the stingless bee Melipona quadrifasciata. There is no difference in colour selection between Osmia and Apis, whereas Melipona discriminates less well in the violet-blue region. The model calculation was used to compare the chromaticity diagrams and the spectral discrimination functions of the three species. It is concluded that the receptor model used in this study predicts the discrimination behaviour of the three bee species very well. Therefore, comparative studies on colour vision in flowervisiting insects may be based on spectral measurements of the photoreceptors, and in many cases this reduces the extent of laborious behavioural studies.

scholarly journals Does conspicuousness scale linearly with colour distance? A test using reef fish

2020 ◽  
Vol 287 (1935) ◽  
pp. 20201456
Author(s):  
Carl Santiago ◽  
Naomi F. Green ◽  
Nadia Hamilton ◽  
John A. Endler ◽  
Daniel C. Osorio ◽  
...  
Keyword(s):  
Reef Fish ◽  
Just Noticeable Difference ◽  
Colour Space ◽  
Perceptual Distance ◽  
The One ◽  
The Relationship ◽  
Colour Signals ◽  
Behavioural Evidence ◽  
Receptor Noise ◽  
Colour Distance

To be effective, animal colour signals must attract attention—and therefore need to be conspicuous. To understand the signal function, it is useful to evaluate their conspicuousness to relevant viewers under various environmental conditions, including when visual scenes are cluttered by objects of varying colour. A widely used metric of colour difference (Δ S ) is based on the receptor noise limited (RNL) model, which was originally proposed to determine when two similar colours appear different from one another, termed the discrimination threshold (or just noticeable difference). Estimates of the perceptual distances between colours that exceed this threshold—termed ‘suprathreshold’ colour differences—often assume that a colour's conspicuousness scales linearly with colour distance, and that this scale is independent of the direction in colour space. Currently, there is little behavioural evidence to support these assumptions. This study evaluated the relationship between Δ S and conspicuousness in suprathreshold colours using an Ishihara-style test with a coral reef fish, Rhinecanthus aculeatus . As our measure of conspicuousness, we tested whether fish, when presented with two colourful targets, preferred to peck at the one with a greater Δ S ­ from the average distractor colour. We found the relationship between Δ S and conspicuousness followed­­ a sigmoidal function, with high Δ S colours perceived as equally conspicuous. We found that the relationship between Δ S and conspicuousness varied across colour space (i.e. for different hues). The sigmoidal detectability curve was little affected by colour variation in the background or when colour distance was calculated using a model that does not incorporate receptor noise. These results suggest that the RNL model may provide accurate estimates for perceptual distance for small suprathreshold distance colours, even in complex viewing environments, but must be used with caution with perceptual distances exceeding­ ­10 Δ S .

Opponent Center-Surround Contrast: Colour to Grey Conversion

2020 ◽  
Vol 2020 (1) ◽  
pp. 105-108
Author(s):  
Ali Alsam
Keyword(s):  
Evolutionary Algorithms ◽  
Three Dimensional ◽  
The State ◽  
Colour Space ◽  
Vision Science ◽  
State Of Art ◽  
Over Time

Vision is the science that informs us about the biological and evolutionary algorithms that our eyes, opticnerves and brains have chosen over time to see. This article is an attempt to solve the problem of colour to grey conversion, by borrowing ideas from vision science. We introduce an algorithm that measures contrast along the opponent colour directions and use the results to combine a three dimensional colour space into a grey. The results indicate that the proposed algorithm competes with the state of art algorithms.

scholarly journals Intruder colour and light environment jointly determine how nesting male stickleback respond to simulated territorial intrusions

2016 ◽  
Vol 12 (8) ◽  
pp. 20160467 ◽  
Author(s):  
Daniel I. Bolnick ◽  
Kimberly Hendrix ◽  
Lyndon Alexander Jordan ◽  
Thor Veen ◽  
Chad D. Brock
Keyword(s):  
Frequency Dependence ◽  
Three Dimensional ◽  
Light Environment ◽  
Depth Gradient ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Negative Frequency Dependent Selection ◽  
Colour Signals

Variation in male nuptial colour signals might be maintained by negative frequency-dependent selection. This can occur if males are more aggressive towards rivals with locally common colour phenotypes. To test this hypothesis, we introduced red or melanic three-dimensional printed-model males into the territories of nesting male stickleback from two optically distinct lakes with different coloured residents. Red-throated models were attacked more in the population with red males, while melanic models were attacked more in the melanic male lake. Aggression against red versus melanic models also varied across a depth gradient within each lake, implying that the local light environment also modulated the strength of negative frequency dependence acting on male nuptial colour.

Nonlinear integration of multispectral information: Human colour vision analogues to sensory integration in rattlesnake

2012 ◽  
Vol 25 (0) ◽  
pp. 179
Author(s):  
Vincent A. Billock ◽  
Brian H. Tsou
Keyword(s):  
Spectral Sensitivity ◽  
Information Integration ◽  
Sensory Integration ◽  
Colour Vision ◽  
Neural Model ◽  
Neural Firing ◽  
Visual Responses ◽  
Neural Synchronization ◽  
Synchronization Mechanism ◽  
Integration Problems

Information integration occurs at every sensory scale and although distinctions are made for integration between and within senses, integration at intermediate scales may exploit familiar mechanisms. Here, we explore this idea by applying a sensory integration mechanism to some poorly understood multispectral integration problems in human colour vision. Billock and Tsou (IMRF, 2011) used a binding-like neural synchronization mechanism to model intensity-dependent (inverse) enhancement of visual responses by auditory stimulation in cat. The same model also applies to mutual enhancement of visual and infrared responses in rattlesnake, suggesting that a similar mechanism could model integration of spectral information in human colour vision. For example, chromatic brightness is thought to be a vector-like nonlinear combination of luminance and chromatic channels; its neural correlate is unknown. We model its spectral sensitivity by pairwise excitatory synchronization between luminance (broadband) neurons and cortically rectified L+M- and S+M-L- LGN neurons. Similarly, the yellow lobe of the yellow-blue opponent channel is known to be a nonlinearly enhanced combination of long- and medium-wavelength-sensitive inputs, but no sensible neural model for this interaction has been advanced. We model the spectral sensitivity of ‘yellowness’ using excitatory synchronization between cortically rectified L+M+S- and M+L- LGN units. The inputs for both simulations were macaque neural firing rate data (DeValois et al., 1966). Fascinatingly, in both cases, multispectral integration in human colour vision was well modeled using the rattlesnake/cat neural synchronization equations without any use of fitting parameters. This is the first application of sensory integration concepts to human colour vision transformations.

Illusory Contours from Pictorially Three-Dimensional Inducing Elements: Counterevidence for Parks and Rock's Example

Perception ◽  
1993 ◽  
Vol 22 (7) ◽  
pp. 809-818 ◽  
Author(s):  
Franco Purghé
Keyword(s):  
Three Dimensional ◽  
Illusory Figure ◽  
Illusory Contours ◽  
Line Elements

In 1990 Parks and Rock claimed that, in pictorially three-dimensional (3-D) inducing patterns, an illusory figure does not emerge if a clear occlusion event is not present. A new pictorially 3-D pattern is presented which contradicts this claim. Two experiments were carried out. The first was aimed at ascertaining the presence of an illusory figure in the new 3-D pattern; the second was aimed at offering evidence that in Parks and Rock's pattern the disappearance of the illusory figure could be due to local interferences caused by the line elements in contact with the inducing borders. The results tend to contradict Parks and Rock's conclusions.

scholarly journals Photoreceptors and diurnal variation in spectral sensitivity in the fiddler crab Gelasimus dampieri

2020 ◽  
Vol 223 (23) ◽  
pp. jeb230979
Author(s):  
Anna-Lee Jessop ◽  
Yuri Ogawa ◽  
Zahra M. Bagheri ◽  
Julian C. Partridge ◽  
Jan M. Hemmi
Keyword(s):  
Spectral Sensitivity ◽  
Colour Vision ◽  
Fiddler Crab ◽  
Selective Adaptation ◽  
Diurnal Changes ◽  
Intracellular Recordings ◽  
Retinular Cell ◽  
Minimum Requirement ◽  
Peak Sensitivity ◽  
Retinular Cells

ABSTRACTColour signals, and the ability to detect them, are important for many animals and can be vital to their survival and fitness. Fiddler crabs use colour information to detect and recognise conspecifics, but their colour vision capabilities remain unclear. Many studies have attempted to measure their spectral sensitivity and identify contributing retinular cells, but the existing evidence is inconclusive. We used electroretinogram (ERG) measurements and intracellular recordings from retinular cells to estimate the spectral sensitivity of Gelasimus dampieri and to track diurnal changes in spectral sensitivity. G. dampieri has a broad spectral sensitivity and is most sensitive to wavelengths between 420 and 460 nm. Selective adaptation experiments uncovered an ultraviolet (UV) retinular cell with a peak sensitivity shorter than 360 nm. The species’ spectral sensitivity above 400 nm is too broad to be fitted by a single visual pigment and using optical modelling, we provide evidence that at least two medium-wavelength sensitive (MWS) visual pigments are contained within a second blue-green sensitive retinular cell. We also found a ∼25 nm diurnal shift in spectral sensitivity towards longer wavelengths in the evening in both ERG and intracellular recordings. Whether the shift is caused by screening pigment migration or changes in opsin expression remains unclear, but the observation shows the diel dynamism of colour vision in this species. Together, these findings support the notion that G. dampieri possesses the minimum requirement for colour vision, with UV and blue/green receptors, and help to explain some of the inconsistent results of previous research.

ANALYSIS ON ATTITUDE POSITION OF EARTH CENTERED INERTIAL (ECI) BASED ON RAZAKSAT DATA

2015 ◽  
Vol 76 (12) ◽  
Author(s):  
Mohd Zamri Hasan ◽  
Sazali Yaacob ◽  
Amran Ahmed ◽  
Nor Hazadura Hamzah ◽  
Shamshul Bahar Yaakob ◽  
...  
Keyword(s):  
Coordinate System ◽  
Reference Frame ◽  
Earth Rotation ◽  
Attitude Determination ◽  
Three Dimensional ◽  
Measurement Data ◽  
Inertial Reference Frame ◽  
Determination System ◽  
Line Elements

Attitude determination system (ADS) is a process to control the orientation of satellite to make sure that the orientation of satellite is relative to inertial reference frame such as Earth. Earth Centered Inertial (ECI) is one of reference frame for satellite that determines the attitude in three dimensional spacecraft. Since RazakSAT orbits on earth, ECI coordinate system will be used for satellite relative to earth rotation. This paper is about the analysis on attitude position of ECI and velocity at X, Y and Z axis based on RazakSAT data. Satellite Tools Kit (STK) is used to estimate the attitude and velocity based on Two Line Elements (TLE) of RazakSAT. The result is compared with RazakSAT measurement data to observe the accuracy of estimation by using STK.

scholarly journals Coevolution of coloration and colour vision?

2017 ◽  
Vol 372 (1724) ◽  
pp. 20160338 ◽  
Author(s):  
Olle Lind ◽  
Miriam J. Henze ◽  
Almut Kelber ◽  
Daniel Osorio
Keyword(s):  
Colour Vision ◽  
Evolutionary Relationship ◽  
Evolutionary Significance ◽  
Adaptive Landscape ◽  
Phenotypic Differences ◽  
Visual Systems ◽  
Future Work ◽  
Colour Signals ◽  
Perception Function ◽  
Key Characters

The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, and for the efficacy and honesty of biological communication. Here we outline current understanding of the diversity of colour vision in two contrasting groups: the phylogenetically conservative birds, and the more variable butterflies. Evidence for coevolution of colour signals and vision exists in both groups, but is limited to observations of phenotypic differences between visual systems, which might be correlated with coloration. Here, to illustrate how one might interpret the evolutionary significance of such differences, we used colour vision modelling based on an avian eye to evaluate the effects of variation in three key characters: photoreceptor spectral sensitivity, oil droplet pigmentation and the proportions of different photoreceptor types. The models predict that physiologically realistic changes in any one character will have little effect, but complementary shifts in all three can substantially affect discriminability of three types of natural spectra. These observations about the adaptive landscape of colour vision may help to explain the general conservatism of photoreceptor spectral sensitivities in birds. This approach can be extended to other types of eye and spectra to inform future work on coevolution of coloration and colour vision. This article is part of the themed issue ‘Animal coloration: production, perception, function and application’.

CHARLES BOURGEOIS (1759-1832), HIS ANTINEWTONIAN COLOUR THEORY AND THE RECONCILEMENT OF ART AND SCIENCE

Nuncius ◽  
2007 ◽  
Vol 22 (1) ◽  
pp. 15-48
Author(s):  
JOOST MERTENS
Keyword(s):  
White Light ◽  
Royal Academy ◽  
Three Dimensional ◽  
Colour Space ◽  
Art And Science ◽  
The Arts ◽  
General Rules ◽  
Colour Theory ◽  
Composite Nature ◽  
Academy Of Sciences

Abstracttitle ABSTRACT /title Between 1810 and 1825, Charles Bourgeois (1759-1832), miniaturist, pigment manufacturer and physicist, developed a colour optics that defied both the Newtonian view of the composite nature of white light and the widely accepted strict separation between science and the arts. In this paper four themes are discussed: the general rules of colour mixing and the resulting three-dimensional colour space CEI (Couleur, Excdent, Intensit); Bourgeois' theory of light as a vehicle for non-luminous colours; His attempt at disproving Newton's central principle of the unequal refrangibility of different colours; and his relation, or rather non-relation, with the Royal Academy of Sciences which considered Bourgeois' theory of light a piece of nonsense.

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