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Hans-michael Poehling - One of the best experts on this subject based on the ideXlab platform.
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blue green opponency and trichromatic vision in the greenhouse whitefly trialeurodes vaporariorum explored using light emitting diodes
Annals of Applied Biology, 2019Co-Authors: Niklas Stukenberg, Hans-michael PoehlingAbstract:Visual Orientation in the greenhouse whitefly ( Trialeurodes vaporariorum Westwood, Hemiptera: Aleyrodidae) is the result of 9wavelength-specific behaviours9. Green-yellow elicits 9settling behaviour9 while ultraviolet (UV) radiation initiates 9migratory behaviour9. Electroretinograms of the photoreceptors9 spectral efficiency showed peaks in the green and the UV range and whitefly vision was said to be dichromatic. In order to study the Visual behaviour of T. vaporariorum , nineteen narrow-bandwidth LEDs covering the UV-A and visible range were used in combination with light scattering acrylic glass screens in a small-scale choice arena under greenhouse conditions. Multiple-choice and dual-choice assays were performed, resulting in LED-based behavioural action spectra of settling (green) and migratory behaviour (UV). A potential inhibitory blue-green chromatic mechanism was studied by combining yellow with different blueish LEDs. Intensity dependencies were illustrated by changing LED intensities. Regarding the 9settling response9, highest attraction was achieved by a green LED with a centroid wavelength of 550 nm, while a blue LED with 469 nm proved to be most inhibitory. Behaviour was distinctly intensity dependent. 9Migratory behaviour9 was elicited the most by the UV LED with the shortest available wavelength of 373 nm. The results clearly prove the presence of a green and a yet undescribed blue sensitive photoreceptor and a blue-green opponent mechanism. Furthermore, empirical colour choice models were built and receptor peaks were estimated around 510 - 520 nm (green), 480 - 490 nm (blue) and 340 - 370 nm (UV). Consequently, Trialeurodes vaporariorum possesses a trichromatic receptor setup.
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Blue-green opponency and trichromatic vision in the greenhouse whitefly (Trialeurodes vaporariorum)
2018Co-Authors: Niklas Stukenberg, Hans-michael PoehlingAbstract:Visual Orientation in the greenhouse whitefly ( Trialeurodes vaporariorum Westwood, Hemiptera: Aleyrodidae) is the result of 9wavelength-specific behaviours9. Green-yellow elicits 9settling behaviour9 while ultraviolet (UV) radiation initiates 9migratory behaviour9. Electroretinograms of the photoreceptors9 spectral efficiency showed peaks in the green and the UV range and whitefly vision was said to be dichromatic. In order to study the Visual behaviour of T. vaporariorum , nineteen narrow-bandwidth LEDs covering the UV-A and visible range were used in combination with light scattering acrylic glass screens in a small-scale choice arena under greenhouse conditions. Multiple-choice and dual-choice assays were performed, resulting in LED-based behavioural action spectra of settling (green) and migratory behaviour (UV). A potential inhibitory blue-green chromatic mechanism was studied by combining yellow with different blueish LEDs. Intensity dependencies were illustrated by changing LED intensities. Regarding the 9settling response9, highest attraction was achieved by a green LED with a centroid wavelength of 550 nm, while a blue LED with 469 nm proved to be most inhibitory. Behaviour was distinctly intensity dependent. 9Migratory behaviour9 was elicited the most by the UV LED with the shortest available wavelength of 373 nm. The results clearly prove the presence of a green and a yet undescribed blue sensitive photoreceptor and a blue-green opponent mechanism. Furthermore, empirical colour choice models were built and receptor peaks were estimated around 510 - 520 nm (green), 480 - 490 nm (blue) and 340 - 370 nm (UV). Consequently, Trialeurodes vaporariorum possesses a trichromatic receptor setup.
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Visual Orientation of the black fungus gnat bradysia difformis explored using leds
Entomologia Experimentalis Et Applicata, 2018Co-Authors: Niklas Stukenberg, Niklas Ahrens, Hans-michael PoehlingAbstract:Fungus gnats occur worldwide with more than 1 700 described species. They can cause serious damages on ornamentals, crop plants, and edible mushrooms, and are considered to be a serious pest in the last years. Bradysia difformisFrey (Diptera: Sciaridae) represents a common species in Europe. Usually, yellow sticky traps are used for monitoring and control in greenhouses and fluorescent tube‐based light traps are additionally applied for control in mushroom cultivation. The importance of such Visual trapping measures for efficient monitoring or alternative control increases in biological and integrated plant protection. However, detailed color preferences of fungus gnats are mostly unknown. We studied the Visual Orientation of B. difformis with light‐emitting diodes (LEDs) in a broad range of peak wavelengths from 371 nm (ultraviolet, UV) to 619 nm (amber). We determined attractive wavelengths in consecutive choice experiments in daylight and darkness. Highest numbers of adult B. difformis were attracted to UV radiation (382 nm) followed by green‐yellow light (532–592 nm). The responses to UV and the green‐yellow range were relatively unspecific and mostly independent from intensity. Combination of UV and yellow LEDs improved trapping efficacy compared to a single UV or yellow LED trap, as well as compared to a common yellow sticky trap. When both wavelengths were compared to a black surface to increase contrasts, the black surface was preferred over yellow, but was less attractive than UV. Thus, B. difformis displays two, probably wavelength‐specific, behaviors to UV radiation and green‐yellow light, with UV being the most attractive stimulus. These behaviors might be directly related to underlying photoreceptors, suggesting dichromatic vision in B. difformis.
Niklas Stukenberg - One of the best experts on this subject based on the ideXlab platform.
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blue green opponency and trichromatic vision in the greenhouse whitefly trialeurodes vaporariorum explored using light emitting diodes
Annals of Applied Biology, 2019Co-Authors: Niklas Stukenberg, Hans-michael PoehlingAbstract:Visual Orientation in the greenhouse whitefly ( Trialeurodes vaporariorum Westwood, Hemiptera: Aleyrodidae) is the result of 9wavelength-specific behaviours9. Green-yellow elicits 9settling behaviour9 while ultraviolet (UV) radiation initiates 9migratory behaviour9. Electroretinograms of the photoreceptors9 spectral efficiency showed peaks in the green and the UV range and whitefly vision was said to be dichromatic. In order to study the Visual behaviour of T. vaporariorum , nineteen narrow-bandwidth LEDs covering the UV-A and visible range were used in combination with light scattering acrylic glass screens in a small-scale choice arena under greenhouse conditions. Multiple-choice and dual-choice assays were performed, resulting in LED-based behavioural action spectra of settling (green) and migratory behaviour (UV). A potential inhibitory blue-green chromatic mechanism was studied by combining yellow with different blueish LEDs. Intensity dependencies were illustrated by changing LED intensities. Regarding the 9settling response9, highest attraction was achieved by a green LED with a centroid wavelength of 550 nm, while a blue LED with 469 nm proved to be most inhibitory. Behaviour was distinctly intensity dependent. 9Migratory behaviour9 was elicited the most by the UV LED with the shortest available wavelength of 373 nm. The results clearly prove the presence of a green and a yet undescribed blue sensitive photoreceptor and a blue-green opponent mechanism. Furthermore, empirical colour choice models were built and receptor peaks were estimated around 510 - 520 nm (green), 480 - 490 nm (blue) and 340 - 370 nm (UV). Consequently, Trialeurodes vaporariorum possesses a trichromatic receptor setup.
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Blue-green opponency and trichromatic vision in the greenhouse whitefly (Trialeurodes vaporariorum)
2018Co-Authors: Niklas Stukenberg, Hans-michael PoehlingAbstract:Visual Orientation in the greenhouse whitefly ( Trialeurodes vaporariorum Westwood, Hemiptera: Aleyrodidae) is the result of 9wavelength-specific behaviours9. Green-yellow elicits 9settling behaviour9 while ultraviolet (UV) radiation initiates 9migratory behaviour9. Electroretinograms of the photoreceptors9 spectral efficiency showed peaks in the green and the UV range and whitefly vision was said to be dichromatic. In order to study the Visual behaviour of T. vaporariorum , nineteen narrow-bandwidth LEDs covering the UV-A and visible range were used in combination with light scattering acrylic glass screens in a small-scale choice arena under greenhouse conditions. Multiple-choice and dual-choice assays were performed, resulting in LED-based behavioural action spectra of settling (green) and migratory behaviour (UV). A potential inhibitory blue-green chromatic mechanism was studied by combining yellow with different blueish LEDs. Intensity dependencies were illustrated by changing LED intensities. Regarding the 9settling response9, highest attraction was achieved by a green LED with a centroid wavelength of 550 nm, while a blue LED with 469 nm proved to be most inhibitory. Behaviour was distinctly intensity dependent. 9Migratory behaviour9 was elicited the most by the UV LED with the shortest available wavelength of 373 nm. The results clearly prove the presence of a green and a yet undescribed blue sensitive photoreceptor and a blue-green opponent mechanism. Furthermore, empirical colour choice models were built and receptor peaks were estimated around 510 - 520 nm (green), 480 - 490 nm (blue) and 340 - 370 nm (UV). Consequently, Trialeurodes vaporariorum possesses a trichromatic receptor setup.
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Visual Orientation of the black fungus gnat bradysia difformis explored using leds
Entomologia Experimentalis Et Applicata, 2018Co-Authors: Niklas Stukenberg, Niklas Ahrens, Hans-michael PoehlingAbstract:Fungus gnats occur worldwide with more than 1 700 described species. They can cause serious damages on ornamentals, crop plants, and edible mushrooms, and are considered to be a serious pest in the last years. Bradysia difformisFrey (Diptera: Sciaridae) represents a common species in Europe. Usually, yellow sticky traps are used for monitoring and control in greenhouses and fluorescent tube‐based light traps are additionally applied for control in mushroom cultivation. The importance of such Visual trapping measures for efficient monitoring or alternative control increases in biological and integrated plant protection. However, detailed color preferences of fungus gnats are mostly unknown. We studied the Visual Orientation of B. difformis with light‐emitting diodes (LEDs) in a broad range of peak wavelengths from 371 nm (ultraviolet, UV) to 619 nm (amber). We determined attractive wavelengths in consecutive choice experiments in daylight and darkness. Highest numbers of adult B. difformis were attracted to UV radiation (382 nm) followed by green‐yellow light (532–592 nm). The responses to UV and the green‐yellow range were relatively unspecific and mostly independent from intensity. Combination of UV and yellow LEDs improved trapping efficacy compared to a single UV or yellow LED trap, as well as compared to a common yellow sticky trap. When both wavelengths were compared to a black surface to increase contrasts, the black surface was preferred over yellow, but was less attractive than UV. Thus, B. difformis displays two, probably wavelength‐specific, behaviors to UV radiation and green‐yellow light, with UV being the most attractive stimulus. These behaviors might be directly related to underlying photoreceptors, suggesting dichromatic vision in B. difformis.
Franco Lepore - One of the best experts on this subject based on the ideXlab platform.
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from cortical blindness to conscious Visual perception theories on neuronal networks and Visual training strategies
Frontiers in Systems Neuroscience, 2017Co-Authors: Vanessa Hadid, Franco LeporeAbstract:Homonymous hemianopia (HH) is the most common cortical Visual impairment leading to blindness in the contralateral hemifield. It is associated with many inconveniences and daily restrictions such as exploration and Visual Orientation difficulties. However, patients with HH can preserve the remarkable ability to unconsciously perceive Visual stimuli presented in their blindfield, a phenomenon known as blindsight. Unfortunately, the nature of this captivating residual ability is still misunderstood and the rehabilitation strategies have been insufficiently exploited. This paper discusses type I and type II blindsight in a neuronal framework of altered global workspace, resulting from inefficient perception, attention and conscious networks. To enhance synchronisation and create global availability for residual abilities to reach Visual consciousness, rehabilitation tools need to stimulate subcortical extrastriate pathways through V5/MT. Multisensory bottom-up compensation combined with top-down restitution training could target pre-existing and new neuronal mechanisms to recreate a framework for potential functionality.
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From Cortical Blindness to Conscious Visual Perception: Theories on Neuronal Networks and Visual Training Strategies
Frontiers Media S.A., 2017Co-Authors: Vanessa Hadid, Franco LeporeAbstract:Homonymous hemianopia (HH) is the most common cortical Visual impairment leading to blindness in the contralateral hemifield. It is associated with many inconveniences and daily restrictions such as exploration and Visual Orientation difficulties. However, patients with HH can preserve the remarkable ability to unconsciously perceive Visual stimuli presented in their blindfield, a phenomenon known as blindsight. Unfortunately, the nature of this captivating residual ability is still misunderstood and the rehabilitation strategies in terms of Visual training have been insufficiently exploited. This article discusses type I and type II blindsight in a neuronal framework of altered global workspace, resulting from inefficient perception, attention and conscious networks. To enhance synchronization and create global availability for residual abilities to reach Visual consciousness, rehabilitation tools need to stimulate subcortical extrastriate pathways through V5/MT. Multisensory bottom-up compensation combined with top-down restitution training could target pre-existing and new neuronal mechanisms to recreate a framework for potential functionality
Roger B H Tootell - One of the best experts on this subject based on the ideXlab platform.
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the radial bias a different slant on Visual Orientation sensitivity in human and nonhuman primates
Neuron, 2006Co-Authors: Yuka Sasaki, Reza Rajimehr, Byoung Woo Kim, L B Ekstrom, Wim Vanduffel, Roger B H TootellAbstract:It is generally assumed that sensitivity to different stimulus Orientations is mapped in a globally equivalent fashion across primate Visual cortex, at a spatial scale larger than that of Orientation columns. However, some evidence predicts instead that radial Orientations should produce higher activity than other Orientations, throughout Visual cortex. Here, this radial Orientation bias was robustly confirmed using (1) human psychophysics, plus fMRI in (2) humans and (3) behaving monkeys. In Visual cortex, fMRI activity was at least 20% higher in the retinotopic representations of polar angle which corresponded to the radial stimulus Orientations (relative to tangential). In a global demonstration of this, we activated complementary retinotopic quadrants of Visual cortex by simply changing stimulus Orientation, without changing stimulus location in the Visual field. This evidence reveals a neural link between Orientation sensitivity and the cortical retinotopy, which have previously been considered independent.
Mürside Sur - One of the best experts on this subject based on the ideXlab platform.
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Induction of Visual Orientation modules in auditory cortex
Nature, 2000Co-Authors: Jitendra Sharma, Alessandra Angelucci, Mürside SurAbstract:Modules of neurons sharing a common property are a basic organizational feature of mammalian sensory cortex. Primary Visual cortex (V1) is characterized by Orientation modules--groups of cells that share a preferred stimulus Orientation--which are organized into a highly ordered Orientation map. Here we show that in ferrets in which retinal projections are routed into the auditory pathway, Visually responsive neurons in 'rewired' primary auditory cortex are also organized into Orientation modules. The Orientation tuning of neurons within these modules is comparable to the tuning of cells in V1 but the Orientation map is less orderly. Horizontal connections in rewired cortex are more patchy and periodic than connections in normal auditory cortex, but less so than connections in V1. These data show that afferent activity has a profound influence on diverse components of cortical circuitry, including thalamocortical and local intracortical connections, which are involved in the generation of Orientation tuning, and long-range horizontal connections, which are important in creating an Orientation map.
